Release 2.1.2 (#2136)

* Implement missing unit-tests
* Bump version
* Update release notes

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,48 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Environment**
+- Patroni version:
+- PostgreSQL version:
+- DCS (and its version):
+
+**Patroni configuration file**
+```
+Please copy&paste your Patroni configuration file here
+```
+
+**patronictl show-config**
+```
+Please copy&paste the output of "patronictl show-config" command here
+```
+
+**Have you checked Patroni logs?**
+Please provide a snippet of Patroni log files here
+
+**Have you checked PostgreSQL logs?**
+Please provide a snippet here
+
+**Have you tried to use GitHub issue search?**
+Maybe there is already a similar issue solved.
+
+
+**Additional context**
+Add any other context about the problem here.

.github/workflows/install_deps.py

@@ -0,0 +1,189 @@
+import inspect
+import os
+import shutil
+import subprocess
+import stat
+import sys
+import tarfile
+import time
+import zipfile
+
+
+def install_requirements(what):
+    old_path = sys.path[:]
+    w = os.path.join(os.getcwd(), os.path.dirname(inspect.getfile(inspect.currentframe())))
+    sys.path.insert(0, os.path.dirname(os.path.dirname(w)))
+    try:
+        from setup import EXTRAS_REQUIRE, read
+    finally:
+        sys.path = old_path
+    requirements = ['mock>=2.0.0', 'flake8', 'pytest', 'pytest-cov'] if what == 'all' else ['behave']
+    requirements += ['coverage']
+    # try to split tests between psycopg2 and psycopg3
+    requirements += ['psycopg[binary]'] if sys.version_info >= (3, 6, 0) and\
+        (sys.platform != 'darwin' or what == 'etcd3') else ['psycopg2-binary']
+    for r in read('requirements.txt').split('\n'):
+        r = r.strip()
+        if r != '':
+            extras = {e for e, v in EXTRAS_REQUIRE.items() if v and any(r.startswith(x) for x in v)}
+            if not extras or what == 'all' or what in extras:
+                requirements.append(r)
+
+    subprocess.call([sys.executable, '-m', 'pip', 'install', '--upgrade', 'pip'])
+    r = subprocess.call([sys.executable, '-m', 'pip', 'install'] + requirements)
+    s = subprocess.call([sys.executable, '-m', 'pip', 'install', '--upgrade', 'setuptools'])
+    return s | r
+
+
+def install_packages(what):
+    from mapping import versions
+
+    packages = {
+        'zookeeper': ['zookeeper', 'zookeeper-bin', 'zookeeperd'],
+        'consul': ['consul'],
+    }
+    packages['exhibitor'] = packages['zookeeper']
+    packages = packages.get(what, [])
+    ver = versions.get(what)
+    subprocess.call(['sudo', 'sed', '-i', 's/pgdg main.*$/pgdg main {0}/'.format(ver),
+                     '/etc/apt/sources.list.d/pgdg.list'])
+    subprocess.call(['sudo', 'apt-get', 'update', '-y'])
+    return subprocess.call(['sudo', 'apt-get', 'install', '-y', 'postgresql-' + ver, 'expect-dev', 'wget'] + packages)
+
+
+def get_file(url, name):
+    try:
+        from urllib.request import urlretrieve
+    except ImportError:
+        from urllib import urlretrieve
+
+    print('Downloading ' + url)
+    urlretrieve(url, name)
+
+
+def untar(archive, name):
+    with tarfile.open(archive) as tar:
+        f = tar.extractfile(name)
+        dest = os.path.basename(name)
+        with open(dest, 'wb') as d:
+            shutil.copyfileobj(f, d)
+            return dest
+
+
+def unzip(archive, name):
+    with zipfile.ZipFile(archive, 'r') as z:
+        name = z.extract(name)
+        dest = os.path.basename(name)
+        shutil.move(name, dest)
+        return dest
+
+
+def unzip_all(archive):
+    print('Extracting ' + archive)
+    with zipfile.ZipFile(archive, 'r') as z:
+        z.extractall()
+
+
+def chmod_755(name):
+    os.chmod(name, stat.S_IRUSR | stat.S_IWUSR | stat.S_IXUSR |
+             stat.S_IRGRP | stat.S_IXGRP | stat.S_IROTH | stat.S_IXOTH)
+
+
+def unpack(archive, name):
+    print('Extracting {0} from {1}'.format(name, archive))
+    func = unzip if archive.endswith('.zip') else untar
+    name = func(archive, name)
+    chmod_755(name)
+    return name
+
+
+def install_etcd():
+    version = os.environ.get('ETCDVERSION', '3.3.13')
+    platform = {'linux2': 'linux', 'win32': 'windows', 'cygwin': 'windows'}.get(sys.platform, sys.platform)
+    dirname = 'etcd-v{0}-{1}-amd64'.format(version, platform)
+    ext = 'tar.gz' if platform == 'linux' else 'zip'
+    name = '{0}.{1}'.format(dirname, ext)
+    url = 'https://github.com/etcd-io/etcd/releases/download/v{0}/{1}'.format(version, name)
+    get_file(url, name)
+    ext = '.exe' if platform == 'windows' else ''
+    return int(unpack(name, '{0}/etcd{1}'.format(dirname, ext)) is None)
+
+
+def install_postgres():
+    version = os.environ.get('PGVERSION', '12.1-1')
+    platform = {'darwin': 'osx', 'win32': 'windows-x64', 'cygwin': 'windows-x64'}[sys.platform]
+    name = 'postgresql-{0}-{1}-binaries.zip'.format(version, platform)
+    get_file('http://get.enterprisedb.com/postgresql/' + name, name)
+    unzip_all(name)
+    bin_dir = os.path.join('pgsql', 'bin')
+    for f in os.listdir(bin_dir):
+        chmod_755(os.path.join(bin_dir, f))
+    subprocess.call(['pgsql/bin/postgres', '-V'])
+    return 0
+
+
+def setup_kubernetes():
+    get_file('https://storage.googleapis.com/minikube/k8sReleases/v1.7.0/localkube-linux-amd64', 'localkube')
+    chmod_755('localkube')
+
+    devnull = open(os.devnull, 'w')
+    subprocess.Popen(['sudo', 'nohup', './localkube', '--logtostderr=true', '--enable-dns=false'],
+                     stdout=devnull, stderr=devnull)
+    for _ in range(0, 120):
+        if subprocess.call(['wget', '-qO', '-', 'http://127.0.0.1:8080/'], stdout=devnull, stderr=devnull) == 0:
+            break
+        time.sleep(1)
+    else:
+        print('localkube did not start')
+        return 1
+
+    subprocess.call('sudo chmod 644 /var/lib/localkube/certs/*', shell=True)
+    print('Set up .kube/config')
+    kube = os.path.join(os.path.expanduser('~'), '.kube')
+    os.makedirs(kube)
+    with open(os.path.join(kube, 'config'), 'w') as f:
+        f.write("""apiVersion: v1
+clusters:
+- cluster:
+    certificate-authority: /var/lib/localkube/certs/ca.crt
+    server: https://127.0.0.1:8443
+  name: local
+contexts:
+- context:
+    cluster: local
+    user: myself
+  name: local
+current-context: local
+kind: Config
+preferences: {}
+users:
+- name: myself
+  user:
+    client-certificate: /var/lib/localkube/certs/apiserver.crt
+    client-key: /var/lib/localkube/certs/apiserver.key
+""")
+    return 0
+
+
+def main():
+    what = os.environ.get('DCS', sys.argv[1] if len(sys.argv) > 1 else 'all')
+
+    if what != 'all':
+        if sys.platform.startswith('linux'):
+            r = install_packages(what)
+            if r == 0 and what == 'kubernetes':
+                r = setup_kubernetes()
+        else:
+            r = install_postgres()
+
+        if r == 0 and what.startswith('etcd'):
+            r = install_etcd()
+
+        if r != 0:
+            return r
+
+    return install_requirements(what)
+
+
+if __name__ == '__main__':
+    sys.exit(main())

.github/workflows/mapping.py

@@ -0,0 +1 @@
+versions = {'etcd': '9.6', 'etcd3': '14', 'consul': '13', 'exhibitor': '12', 'raft': '11', 'kubernetes': '14'}

.github/workflows/run_tests.py

@@ -0,0 +1,50 @@
+import os
+import shutil
+import subprocess
+import sys
+import tempfile
+
+
+def main():
+    what = os.environ.get('DCS', sys.argv[1] if len(sys.argv) > 1 else 'all')
+
+    if what == 'all':
+        flake8 = subprocess.call([sys.executable, 'setup.py', 'flake8'])
+        test = subprocess.call([sys.executable, 'setup.py', 'test'])
+        version = '.'.join(map(str, sys.version_info[:2]))
+        shutil.move('.coverage', os.path.join(tempfile.gettempdir(), '.coverage.' + version))
+        return flake8 | test
+    elif what == 'combine':
+        tmp = tempfile.gettempdir()
+        for name in os.listdir(tmp):
+            if name.startswith('.coverage.'):
+                shutil.move(os.path.join(tmp, name), name)
+        return subprocess.call([sys.executable, '-m', 'coverage', 'combine'])
+
+    env = os.environ.copy()
+    if sys.platform.startswith('linux'):
+        from mapping import versions
+
+        version = versions.get(what)
+        path = '/usr/lib/postgresql/{0}/bin:.'.format(version)
+        unbuffer = ['timeout', '600', 'unbuffer']
+        args = ['--tags=-skip'] if what == 'etcd' else []
+    else:
+        path = os.path.abspath(os.path.join('pgsql', 'bin'))
+        if sys.platform == 'darwin':
+            path += ':.'
+        args = unbuffer = []
+    env['PATH'] = path + os.pathsep + env['PATH']
+    env['DCS'] = what
+
+    ret = subprocess.call(unbuffer + [sys.executable, '-m', 'behave'] + args, env=env)
+
+    if ret != 0:
+        if subprocess.call('grep . features/output/*_failed/*postgres?.*', shell=True) != 0:
+            subprocess.call('grep . features/output/*/*postgres?.*', shell=True)
+        return 1
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())

.github/workflows/tests.yaml

@@ -0,0 +1,177 @@
+name: Tests
+
+on:
+  pull_request:
+  push:
+    branches:
+    - master
+    tags:
+    - v.*
+
+jobs:
+  unit:
+    runs-on: ${{ matrix.os }}-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu, windows, macos]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python 2.7
+      uses: actions/setup-python@v2
+      with:
+        python-version: 2.7
+      if: matrix.os != 'windows'
+    - name: Install dependencies
+      run: python .github/workflows/install_deps.py
+      if: matrix.os != 'windows'
+    - name: Run tests and flake8
+      run: python .github/workflows/run_tests.py
+      if: matrix.os != 'windows'
+
+    - name: Set up Python 3.5
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.5
+    - name: Install dependencies
+      run: python .github/workflows/install_deps.py
+    - name: Run tests and flake8
+      run: python .github/workflows/run_tests.py
+
+    - name: Set up Python 3.6
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.6
+    - name: Install dependencies
+      run: python .github/workflows/install_deps.py
+    - name: Run tests and flake8
+      run: python .github/workflows/run_tests.py
+
+    - name: Set up Python 3.7
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.7
+    - name: Install dependencies
+      run: python .github/workflows/install_deps.py
+    - name: Run tests and flake8
+      run: python .github/workflows/run_tests.py
+
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.8
+    - name: Install dependencies
+      run: python .github/workflows/install_deps.py
+    - name: Run tests and flake8
+      run: python .github/workflows/run_tests.py
+
+    - name: Set up Python 3.9
+      uses: actions/setup-python@v2
+      with:
+        python-version: 3.9
+    - name: Install dependencies
+      run: python .github/workflows/install_deps.py
+    - name: Run tests and flake8
+      run: python .github/workflows/run_tests.py
+
+    - name: Combine coverage
+      run: python .github/workflows/run_tests.py combine
+
+    - name: Install coveralls
+      run: python -m pip install coveralls
+
+    - name: Upload Coverage
+      env:
+        COVERALLS_FLAG_NAME: unit-${{ matrix.os }}
+        COVERALLS_PARALLEL: 'true'
+        GITHUB_TOKEN: ${{ secrets.github_token }}
+      run: python -m coveralls --service=github
+
+    - name: Run codacy-coverage-reporter
+      uses: codacy/codacy-coverage-reporter-action@master
+      env:
+        SECRETS_AVAILABLE: ${{ secrets.CODACY_PROJECT_TOKEN != '' }}
+      with:
+        project-token: ${{ secrets.CODACY_PROJECT_TOKEN }}
+        coverage-reports: coverage.xml
+      if: ${{ matrix.os == 'ubuntu' && env.SECRETS_AVAILABLE == 'true' }}
+
+  behave:
+    runs-on: ${{ matrix.os }}-latest
+    env:
+      DCS: ${{ matrix.dcs }}
+      ETCDVERSION: 3.3.13
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu]
+        python-version: [2.7, 3.5, 3.8]
+        dcs: [etcd, etcd3, consul, exhibitor, kubernetes, raft]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Add postgresql apt repo
+      run: sudo sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
+    - name: Install dependencies
+      run: python .github/workflows/install_deps.py
+    - name: Run behave tests
+      run: python .github/workflows/run_tests.py
+    - uses: actions/setup-python@v2
+      with:
+        python-version: 3.9
+    - name: Install coveralls
+      run: python -m pip install coveralls
+    - name: Upload Coverage
+      env:
+        COVERALLS_FLAG_NAME: behave-${{ matrix.os }}-${{ matrix.dcs }}-${{ matrix.python-version }}
+        COVERALLS_PARALLEL: 'true'
+        GITHUB_TOKEN: ${{ secrets.github_token }}
+      run: python -m coveralls --service=github
+
+  behavem:
+    runs-on: ${{ matrix.os }}-latest
+    env:
+      DCS: ${{ matrix.dcs }}
+      ETCDVERSION: 3.3.13
+      PGVERSION: 12.1-1  # for windows and macos
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos]  #, windows]
+        python-version: [3.7]
+        dcs: [etcd, etcd3, raft]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: python .github/workflows/install_deps.py
+    - name: Run behave tests
+      run: python .github/workflows/run_tests.py
+    - name: Install coveralls
+      run: python -m pip install coveralls
+    - name: Upload Coverage
+      env:
+        COVERALLS_FLAG_NAME: behave-${{ matrix.os }}-${{ matrix.dcs }}-${{ matrix.python-version }}
+        COVERALLS_PARALLEL: 'true'
+        GITHUB_TOKEN: ${{ secrets.github_token }}
+      run: python -m coveralls --service=github
+
+  coveralls-finish:
+    name: Finalize coveralls.io
+    needs: [unit, behave, behavem]
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/setup-python@v2
+    - run: python -m pip install coveralls
+    - run: python -m coveralls --service=github --finish
+      env:
+        GITHUB_TOKEN: ${{ secrets.github_token }}

.travis.yml

@@ -1,157 +0,0 @@
-sudo: true
-dist: trusty
-language: python
-addons:
-  apt:
-    packages:
-      - expect-dev # for unbuffer
-env:
-  global:
-  - ETCDVERSION=3.0.17 ZKVERSION=3.4.14 CONSULVERSION=0.7.4
-  - PYVERSIONS="2.7 3.5 3.6"
-  - EXCLUDE_BEHAVE="3.5"
-  - BOTO_CONFIG=/doesnotexist
-matrix:
-  include:
-  - python: "3.5"
-    env: TEST_SUITE="python setup.py"
-  - python: "3.6"
-    env: DCS="etcd" TEST_SUITE="behave"
-  - python: "3.6"
-    env: DCS="exhibitor" TEST_SUITE="behave"
-  - python: "3.6"
-    env: DCS="consul" TEST_SUITE="behave"
-  - python: "3.6"
-    env: DCS="kubernetes" TEST_SUITE="behave"
-branches:
-  only:
-  - master
-  - /^v\d+\.\d+(\.\d+)?$/
-cache:
-  directories:
-  - $HOME/mycache
-before_cache:
-- |
-  rm -fr $HOME/mycache/python*
-  for pv in $PYVERSIONS; do
-      if [[ $TEST_SUITE != "behave" || $pv != $EXCLUDE_BEHAVE ]]; then
-          fpv=$(basename $(readlink $HOME/virtualenv/python${pv}))
-          mv $HOME/virtualenv/${fpv} $HOME/mycache/${fpv}
-      fi
-  done
-install:
-  - |
-    set -e
-
-    if [[ $TEST_SUITE == "behave" ]]; then
-        function get_consul() {
-            CC=~/mycache/consul_${CONSULVERSION}
-            if [[ ! -x $CC ]]; then
-                curl -L https://releases.hashicorp.com/consul/${CONSULVERSION}/consul_${CONSULVERSION}_linux_amd64.zip \
-                    | gunzip > $CC
-                [[ ${PIPESTATUS[0]} == 0 ]] || return 1
-                chmod +x $CC
-            fi
-            ln -s $CC consul
-        }
-
-        function get_etcd() {
-            EC=~/mycache/etcd_${ETCDVERSION}
-            if [[ ! -x $EC ]]; then
-                curl -L https://github.com/coreos/etcd/releases/download/v${ETCDVERSION}/etcd-v${ETCDVERSION}-linux-amd64.tar.gz \
-                    | tar xz -C . --strip=1 --wildcards --no-anchored etcd
-                [[ ${PIPESTATUS[0]} == 0 ]] || return 1
-                mv etcd $EC
-            fi
-            ln -s $EC etcd
-        }
-
-        function get_kubernetes() {
-            wget -O localkube "https://storage.googleapis.com/minikube/k8sReleases/v1.7.0/localkube-linux-amd64"
-            chmod +x localkube
-            sudo nohup ./localkube --logtostderr=true --enable-dns=false > localkube.log 2>&1 &
-
-            echo "Waiting for localkube to start..."
-            if ! timeout 120 sh -c "while ! curl -ks http://127.0.0.1:8080/ >/dev/null; do sleep 1; done"; then
-                sudo cat localkube.log
-                echo "localkube did not start"
-                exit 1
-            fi
-            echo "Check certificate permissions"
-            sudo chmod 644 /var/lib/localkube/certs/*
-            sudo ls -altr /var/lib/localkube/certs/
-
-            echo "Set up .kube/config"
-            mkdir ~/.kube
-            echo -e "apiVersion: v1\nclusters:\n- cluster:\n    certificate-authority: /var/lib/localkube/certs/ca.crt\n    server: https://127.0.0.1:8443\n  name: local\ncontexts:\n- context:\n    cluster: local\n    user: myself\n  name: local\ncurrent-context: local\nkind: Config\npreferences: {}\nusers:\n- name: myself\n  user:\n    client-certificate: /var/lib/localkube/certs/apiserver.crt\n    client-key: /var/lib/localkube/certs/apiserver.key\n" > ~/.kube/config
-        }
-
-        function get_exhibitor() {
-            ZC=~/mycache/zookeeper-${ZKVERSION}
-            if [[ ! -d $ZC ]]; then
-                curl -L http://www.apache.org/dist/zookeeper/zookeeper-${ZKVERSION}/zookeeper-${ZKVERSION}.tar.gz | tar xz
-                [[ ${PIPESTATUS[0]} == 0 ]] || return 1
-                mv zookeeper-${ZKVERSION}/conf/zoo_sample.cfg zookeeper-${ZKVERSION}/conf/zoo.cfg
-                mv zookeeper-${ZKVERSION} $ZC
-            fi
-            $ZC/bin/zkServer.sh start
-            # following lines are 'emulating' exhibitor REST API
-            while true; do
-                echo -e 'HTTP/1.0 200 OK\nContent-Type: application/json\n\n{"servers":["127.0.0.1"],"port":2181}' \
-                    | nc -l 8181 &> /dev/null
-            done&
-        }
-
-        attempt_num=1
-        until get_${DCS}; do
-            [[ $attempt_num -ge 3 ]] && exit 1
-            echo "Attempt $attempt_num failed! Trying again in $attempt_num seconds..."
-            sleep $(( attempt_num++ ))
-        done
-    fi
-
-    for pv in $PYVERSIONS; do
-        if [[ $TEST_SUITE != "behave" || $pv != $EXCLUDE_BEHAVE ]]; then
-            fpv=$(basename $(readlink $HOME/virtualenv/python$pv))
-            if [[ -d ~/mycache/${fpv} ]]; then
-                mv ~/virtualenv/${fpv} ~/virtualenv/${fpv}.bckp
-                mv ~/mycache/${fpv} ~/virtualenv/${fpv}
-            fi
-            source ~/virtualenv/python${pv}/bin/activate
-            # explicitly install all needed python modules to cache them
-            for p in '-r requirements.txt' 'psycopg2-binary behave codacy-coverage coverage coveralls flake8 mock pytest-cov pytest setuptools'; do
-                pip install $p --upgrade
-            done
-        fi
-    done
-script:
-  - |
-    for pv in $PYVERSIONS; do
-        if [[ $TEST_SUITE == "behave" && $pv == $EXCLUDE_BEHAVE ]]; then
-            continue
-        fi
-
-        source ~/virtualenv/python${pv}/bin/activate
-
-        if [[ $TEST_SUITE != "behave" ]]; then
-            echo Running unit tests using python${pv}
-            unbuffer $TEST_SUITE test
-            $TEST_SUITE flake8
-        elif [[ $pv != $EXCLUDE_BEHAVE ]]; then
-            echo Running acceptance tests using python${pv}
-            if ! PATH=.:/usr/lib/postgresql/9.6/bin:$PATH unbuffer $TEST_SUITE; then
-                # output all log files when tests are failing
-                grep . features/output/*_failed/*postgres?.*
-                exit 1
-            fi
-        fi
-    done
-
-    set +e
-after_success:
-  # before_cache is executed earlier than after_success, so we need to restore one of virtualenv directories
-  - fpv=$(basename $(readlink $HOME/virtualenv/python3.6)) && mv $HOME/mycache/${fpv} $HOME/virtualenv/${fpv}
-  - coveralls
-  - if [[ $TEST_SUITE != "behave" ]]; then python-codacy-coverage -r coverage.xml; fi
-  - if [[ $DCS == "exhibitor" ]]; then ~/mycache/zookeeper-${ZKVERSION}/bin/zkServer.sh stop; fi
-  - sudo kill $(jobs -p)

Dockerfile

@@ -14,7 +14,7 @@ ARG PGDATA
 ARG LC_ALL
 ARG LANG
 
-ENV ETCDVERSION=2.3.8 CONFDVERSION=0.16.0
+ENV ETCDVERSION=3.3.13 CONFDVERSION=0.16.0
 
 RUN set -ex \
     && export DEBIAN_FRONTEND=noninteractive \

README.rst

@@ -1,4 +1,4 @@
-|Build Status| |Coverage Status|
+|Tests Status| |Coverage Status|
 
 Patroni: A Template for PostgreSQL HA with ZooKeeper, etcd or Consul
 --------------------------------------------------------------------
@@ -12,6 +12,8 @@ Patroni is a template for you to create your own customized, high-availability s
 
 We call Patroni a "template" because it is far from being a one-size-fits-all or plug-and-play replication system. It will have its own caveats. Use wisely.
 
+Currently supported PostgreSQL versions: 9.3 to 14.
+
 **Note to Kubernetes users**: Patroni can run natively on top of Kubernetes. Take a look at the `Kubernetes <https://github.com/zalando/patroni/blob/master/docs/kubernetes.rst>`__ chapter of the Patroni documentation.
 
 .. contents::
@@ -59,7 +61,7 @@ To install requirements on a Mac, run the following:
 
     brew install postgresql etcd haproxy libyaml python
 
-**Psycopg2**
+**Psycopg**
 
 Starting from `psycopg2-2.8 <http://initd.org/psycopg/articles/2019/04/04/psycopg-28-released/>`__ the binary version of psycopg2 will no longer be installed by default. Installing it from the source code requires C compiler and postgres+python dev packages.
 Since in the python world it is not possible to specify dependency as ``psycopg2 OR psycopg2-binary`` you will have to decide how to install it.
@@ -86,6 +88,12 @@ There are a few options available:
 
     pip install psycopg2>=2.5.4
 
+4. Use psycopg 3.0 instead of psycopg2
+
+::
+
+    pip install psycopg[binary]
+
 **General installation for pip**
 
 Patroni can be installed with pip:
@@ -96,7 +104,7 @@ Patroni can be installed with pip:
 
 where dependencies can be either empty, or consist of one or more of the following:
 
-etcd
+etcd or etcd3
     `python-etcd` module in order to use Etcd as DCS
 consul
     `python-consul` module in order to use Consul as DCS
@@ -106,6 +114,8 @@ exhibitor
     `kazoo` module in order to use Exhibitor as DCS (same dependencies as for Zookeeper)
 kubernetes
     `kubernetes` module in order to use Kubernetes as DCS in Patroni
+raft
+    `pysyncobj` module in order to use python Raft implementation as DCS
 aws
     `boto` in order to use AWS callbacks
 
@@ -115,7 +125,7 @@ For example, the command in order to install Patroni together with dependencies
 
     pip install patroni[etcd,aws]
 
-Note that external tools to call in the replica creation or custom bootstap scripts (i.e. WAL-E) should be installed independently of Patroni.
+Note that external tools to call in the replica creation or custom bootstrap scripts (i.e. WAL-E) should be installed independently of Patroni.
 
 =======================
 Running and Configuring
@@ -124,7 +134,7 @@ Running and Configuring
 To get started, do the following from different terminals:
 ::
 
-    > etcd --data-dir=data/etcd
+    > etcd --data-dir=data/etcd --enable-v2=true
     > ./patroni.py postgres0.yml
     > ./patroni.py postgres1.yml
 
@@ -167,7 +177,7 @@ Applications Should Not Use Superusers
 
 When connecting from an application, always use a non-superuser. Patroni requires access to the database to function properly. By using a superuser from an application, you can potentially use the entire connection pool, including the connections reserved for superusers, with the ``superuser_reserved_connections`` setting. If Patroni cannot access the Primary because the connection pool is full, behavior will be undesirable.
 
-.. |Build Status| image:: https://travis-ci.org/zalando/patroni.svg?branch=master
-   :target: https://travis-ci.org/zalando/patroni
+.. |Tests Status| image:: https://github.com/zalando/patroni/actions/workflows/tests.yaml/badge.svg
+   :target: https://github.com/zalando/patroni/actions/workflows/tests.yaml?query=branch%3Amaster
 .. |Coverage Status| image:: https://coveralls.io/repos/zalando/patroni/badge.svg?branch=master
-   :target: https://coveralls.io/r/zalando/patroni?branch=master
+   :target: https://coveralls.io/github/zalando/patroni?branch=master

docker-compose.yml

@@ -6,57 +6,31 @@ networks:
     demo:
 
 services:
-    etcd1:
+    etcd1: &etcd
         image: patroni
         networks: [ demo ]
-        env_file: docker/etcd.env
+        environment:
+            ETCD_LISTEN_PEER_URLS: http://0.0.0.0:2380
+            ETCD_LISTEN_CLIENT_URLS: http://0.0.0.0:2379
+            ETCD_INITIAL_CLUSTER: etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380
+            ETCD_INITIAL_CLUSTER_STATE: new
+            ETCD_INITIAL_CLUSTER_TOKEN: tutorial
         container_name: demo-etcd1
         hostname: etcd1
         command: etcd -name etcd1 -initial-advertise-peer-urls http://etcd1:2380
 
     etcd2:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/etcd.env
+        <<: *etcd
         container_name: demo-etcd2
         hostname: etcd2
         command: etcd -name etcd2 -initial-advertise-peer-urls http://etcd2:2380
 
     etcd3:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/etcd.env
+        <<: *etcd
         container_name: demo-etcd3
         hostname: etcd3
         command: etcd -name etcd3 -initial-advertise-peer-urls http://etcd3:2380
 
-    patroni1:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/patroni.env
-        hostname: patroni1
-        container_name: demo-patroni1
-        environment:
-            PATRONI_NAME: patroni1
-
-    patroni2:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/patroni.env
-        hostname: patroni2
-        container_name: demo-patroni2
-        environment:
-            PATRONI_NAME: patroni2
-
-    patroni3:
-        image: patroni
-        networks: [ demo ]
-        env_file: docker/patroni.env
-        hostname: patroni3
-        container_name: demo-patroni3
-        environment:
-            PATRONI_NAME: patroni3
-
     haproxy:
         image: patroni
         networks: [ demo ]
@@ -67,3 +41,37 @@ services:
             - "5000:5000"
             - "5001:5001"
         command: haproxy
+        environment: &haproxy_env
+            ETCDCTL_ENDPOINTS: http://etcd1:2379,http://etcd2:2379,http://etcd3:2379
+            PATRONI_ETCD3_HOSTS: "'etcd1:2379','etcd2:2379','etcd3:2379'"
+            PATRONI_SCOPE: demo
+
+    patroni1:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni1
+        container_name: demo-patroni1
+        environment:
+            <<: *haproxy_env
+            PATRONI_NAME: patroni1
+
+    patroni2:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni2
+        container_name: demo-patroni2
+        environment:
+            <<: *haproxy_env
+            PATRONI_NAME: patroni2
+
+    patroni3:
+        image: patroni
+        networks: [ demo ]
+        env_file: docker/patroni.env
+        hostname: patroni3
+        container_name: demo-patroni3
+        environment:
+            <<: *haproxy_env
+            PATRONI_NAME: patroni3

docker/entrypoint.sh

@@ -25,7 +25,7 @@ case "$1" in
             while ! etcdctl cluster-health 2> /dev/null; do
                 sleep 1
             done
-            exec dumb-init $CONFD etcd -node $(echo $ETCDCTL_ENDPOINTS | sed 's/,/ -node /g')
+            exec dumb-init $CONFD etcdv3 -node $(echo $ETCDCTL_ENDPOINTS | sed 's/,/ -node /g')
         fi
         ;;
     etcd)
@@ -37,7 +37,7 @@ case "$1" in
 esac
 
 ## We start an etcd
-if [ -z "$PATRONI_ETCD_HOSTS" ] && [ -z "$PATRONI_ZOOKEEPER_HOSTS" ]; then
+if [ -z "$PATRONI_ETCD3_HOSTS" ] && [ -z "$PATRONI_ZOOKEEPER_HOSTS" ]; then
     export PATRONI_ETCD_URL="http://127.0.0.1:2379"
     etcd --data-dir /tmp/etcd.data -advertise-client-urls=$PATRONI_ETCD_URL -listen-client-urls=http://0.0.0.0:2379 > /var/log/etcd.log 2> /var/log/etcd.err &
 fi

docker/etcd.env

@@ -1,5 +0,0 @@
-ETCD_LISTEN_PEER_URLS=http://0.0.0.0:2380
-ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379
-ETCD_INITIAL_CLUSTER=etcd1=http://etcd1:2380,etcd2=http://etcd2:2380,etcd3=http://etcd3:2380
-ETCD_INITIAL_CLUSTER_STATE=new
-ETCD_INITIAL_CLUSTER_TOKEN=tutorial

docker/patroni.env

@@ -1,6 +1,3 @@
-PATRONI_SCOPE=demo
-PATRONI_ETCD_HOSTS='etcd1:2379','etcd2:2379','etcd3:2379'
-
 PATRONI_RESTAPI_USERNAME=admin
 PATRONI_RESTAPI_PASSWORD=admin
 PATRONI_SUPERUSER_USERNAME=postgres
@@ -9,6 +6,3 @@ PATRONI_REPLICATION_USERNAME=replicator
 PATRONI_REPLICATION_PASSWORD=replicate
 PATRONI_admin_PASSWORD=admin
 PATRONI_admin_OPTIONS=createdb,createrole
-
-# for etcdctl
-ETCDCTL_ENDPOINTS=http://etcd1:2379,http://etcd2:2379,http://etcd3:2379

docs/CONTRIBUTING.rst

@@ -10,6 +10,39 @@ Chatting
 
 Just want to chat with other Patroni users?  Looking for interactive troubleshooting help? Join us on channel #patroni in the `PostgreSQL Slack <https://postgres-slack.herokuapp.com/>`__.
 
+Running tests
+-------------
+
+Requirements for running behave tests:
+
+1. PostgreSQL packages need to be installed.
+2. PostgreSQL binaries must be available in your `PATH`. You may need to add them to the path with something like `PATH=/usr/lib/postgresql/11/bin:$PATH python -m behave`.
+3. If you'd like to test with external DCSs (e.g., Etcd, Consul, and Zookeeper) you'll need the packages installed and respective services running and accepting unencrypted/unprotected connections on localhost and default port. In the case of Etcd or Consul, the behave test suite could start them up if binaries are available in the `PATH`.
+
+ Install dependencies:
+
+.. code-block:: bash
+
+    # You may want to use Virtualenv or specify pip3.
+    pip install -r requirements.txt
+    pip install -r requirements.dev.txt
+
+After you have all dependencies installed, you can run the various test suites:
+
+.. code-block:: bash
+
+    # You may want to use Virtualenv or specify python3.
+
+    # Run flake8 to check syntax and formatting:
+    python setup.py flake8
+
+    # Run the pytest suite in tests/:
+    python setup.py test
+
+    # Run the behave (https://behave.readthedocs.io/en/latest/) test suite in features/;
+    # modify DCS as desired (raft has no dependencies so is the easiest to start with):
+    DCS=raft python -m behave
+
 Reporting issues
 ----------------
 

docs/ENVIRONMENT.rst

@@ -59,16 +59,36 @@ Etcd
 -  **PATRONI\_ETCD\_USE\_PROXIES**: If this parameter is set to true, Patroni will consider **hosts** as a list of proxies and will not perform a topology discovery of etcd cluster but stick to a fixed list of **hosts**.
 -  **PATRONI\_ETCD\_PROTOCOL**: http or https, if not specified http is used. If the **url** or **proxy** is specified - will take protocol from them.
 -  **PATRONI\_ETCD\_HOST**: the host:port for the etcd endpoint.
--  **PATRONI\_ETCD\_SRV**: Domain to search the SRV record(s) for cluster autodiscovery.
+-  **PATRONI\_ETCD\_SRV**: Domain to search the SRV record(s) for cluster autodiscovery. Patroni will try to query these SRV service names for specified domain (in that order until first success): ``_etcd-client-ssl``, ``_etcd-client``, ``_etcd-ssl``, ``_etcd``, ``_etcd-server-ssl``, ``_etcd-server``. If SRV records for ``_etcd-server-ssl`` or ``_etcd-server`` are retrieved then ETCD peer protocol is used do query ETCD for available members. Otherwise hosts from SRV records will be used.
+-  **PATRONI\_ETCD\_SRV\_SUFFIX**: Configures a suffix to the SRV name that is queried during discovery. Use this flag to differentiate between multiple etcd clusters under the same domain. Works only with conjunction with **PATRONI\_ETCD\_SRV**. For example, if ``PATRONI_ETCD_SRV_SUFFIX=foo`` and ``PATRONI_ETCD_SRV=example.org`` are set, the following DNS SRV query is made:``_etcd-client-ssl-foo._tcp.example.com`` (and so on for every possible ETCD SRV service name).
 -  **PATRONI\_ETCD\_USERNAME**: username for etcd authentication.
 -  **PATRONI\_ETCD\_PASSWORD**: password for etcd authentication.
 -  **PATRONI\_ETCD\_CACERT**: The ca certificate. If present it will enable validation.
 -  **PATRONI\_ETCD\_CERT**: File with the client certificate.
 -  **PATRONI\_ETCD\_KEY**: File with the client key. Can be empty if the key is part of certificate.
 
+Etcdv3
+------
+Environment names for Etcdv3 are similar as for Etcd, you just need to use ``ETCD3`` instead of ``ETCD`` in the variable name. Example: ``PATRONI_ETCD3_HOST``, ``PATRONI_ETCD3_CACERT``, and so on.
+
+.. warning::
+    Keys created with protocol version 2 are not visible with protocol version 3 and the other way around, therefore it is not possible to switch from Etcd to Etcdv3 just by updating Patroni configuration.
+
+
 ZooKeeper
 ---------
--  **PATRONI\_ZOOKEEPER\_HOSTS**: comma separated list of ZooKeeper cluster members: "'host1:port1','host2:port2','etc...'". It is important to quote every single entity!
+-  **PATRONI\_ZOOKEEPER\_HOSTS**: Comma separated list of ZooKeeper cluster members: "'host1:port1','host2:port2','etc...'". It is important to quote every single entity!
+-  **PATRONI\_ZOOKEEPER\_USE\_SSL**: (optional) Whether SSL is used or not. Defaults to ``false``. If set to ``false``, all SSL specific parameters are ignored.
+-  **PATRONI\_ZOOKEEPER\_CACERT**: (optional) The CA certificate. If present it will enable validation.
+-  **PATRONI\_ZOOKEEPER\_CERT**: (optional) File with the client certificate.
+-  **PATRONI\_ZOOKEEPER\_KEY**: (optional) File with the client key.
+-  **PATRONI\_ZOOKEEPER\_KEY\_PASSWORD**: (optional) The client key password.
+-  **PATRONI\_ZOOKEEPER\_VERIFY**: (optional) Whether to verify certificate or not. Defaults to ``true``.
+-  **PATRONI\_ZOOKEEPER\_SET\_ACLS**: (optional) If set, configure Kazoo to apply a default ACL to each ZNode that it creates. ACLs will assume 'x509' schema and should be specified as a dictionary with the principal as the key and one or more permissions as a list in the value.  Permissions may be one of ``CREATE``, ``READ``, ``WRITE``, ``DELETE`` or ``ADMIN``.  For example, ``set_acls: {CN=principal1: [CREATE, READ], CN=principal2: [ALL]}``.
+
+.. note::
+    It is required to install ``kazoo>=2.6.0`` to support SSL.
+
 
 Exhibitor
 ---------
@@ -79,6 +99,7 @@ Exhibitor
 
 Kubernetes
 ----------
+-  **PATRONI\_KUBERNETES\_BYPASS\_API\_SERVICE**: (optional) When communicating with the Kubernetes API, Patroni is usually relying on the `kubernetes` service, the address of which is exposed in the pods via the `KUBERNETES_SERVICE_HOST` environment variable. If `PATRONI_KUBERNETES_BYPASS_API_SERVICE` is set to ``true``, Patroni will resolve the list of API nodes behind the service and connect directly to them.
 -  **PATRONI\_KUBERNETES\_NAMESPACE**: (optional) Kubernetes namespace where the Patroni pod is running. Default value is `default`.
 -  **PATRONI\_KUBERNETES\_LABELS**: Labels in format ``{label1: value1, label2: value2}``. These labels will be used to find existing objects (Pods and either Endpoints or ConfigMaps) associated with the current cluster. Also Patroni will set them on every object (Endpoint or ConfigMap) it creates.
 -  **PATRONI\_KUBERNETES\_SCOPE\_LABEL**: (optional) name of the label containing cluster name. Default value is `cluster-name`.
@@ -86,6 +107,16 @@ Kubernetes
 -  **PATRONI\_KUBERNETES\_USE\_ENDPOINTS**: (optional) if set to true, Patroni will use Endpoints instead of ConfigMaps to run leader elections and keep cluster state.
 -  **PATRONI\_KUBERNETES\_POD\_IP**: (optional) IP address of the pod Patroni is running in. This value is required when `PATRONI_KUBERNETES_USE_ENDPOINTS` is enabled and is used to populate the leader endpoint subsets when the pod's PostgreSQL is promoted.
 -  **PATRONI\_KUBERNETES\_PORTS**: (optional) if the Service object has the name for the port, the same name must appear in the Endpoint object, otherwise service won't work. For example, if your service is defined as ``{Kind: Service, spec: {ports: [{name: postgresql, port: 5432, targetPort: 5432}]}}``, then you have to set ``PATRONI_KUBERNETES_PORTS='[{"name": "postgresql", "port": 5432}]'`` and Patroni will use it for updating subsets of the leader Endpoint. This parameter is used only if `PATRONI_KUBERNETES_USE_ENDPOINTS` is set.
+-  **PATRONI\_KUBERNETES\_CACERT**: (optional) Specifies the file with the CA_BUNDLE file with certificates of trusted CAs to use while verifying Kubernetes API SSL certs. If not provided, patroni will use the value provided by the ServiceAccount secret.
+
+Raft
+----
+
+-  **PATRONI\_RAFT\_SELF\_ADDR**: ``ip:port`` to listen on for Raft connections. The ``self_addr`` must be accessible from other nodes of the cluster. If not set, the node will not participate in consensus.
+-  **PATRONI\_RAFT\_BIND\_ADDR**: (optional) ``ip:port`` to listen on for Raft connections. If not specified the ``self_addr`` will be used.
+-  **PATRONI\_RAFT\_PARTNER\_ADDRS**: list of other Patroni nodes in the cluster in format ``"'ip1:port1','ip2:port2'"``. It is important to quote every single entity!
+-  **PATRONI\_RAFT\_DATA\_DIR**: directory where to store Raft log and snapshot. If not specified the current working directory is used.
+-  **PATRONI\_RAFT\_PASSWORD**: (optional) Encrypt Raft traffic with a specified password, requires ``cryptography`` python module.
 
 PostgreSQL
 ----------
@@ -99,23 +130,35 @@ PostgreSQL
 -  **PATRONI\_REPLICATION\_PASSWORD**: replication password; the user will be created during initialization.
 -  **PATRONI\_REPLICATION\_SSLMODE**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
 -  **PATRONI\_REPLICATION\_SSLKEY**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+-  **PATRONI\_REPLICATION\_SSLPASSWORD**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``PATRONI_REPLICATION_SSLKEY``.
 -  **PATRONI\_REPLICATION\_SSLCERT**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
 -  **PATRONI\_REPLICATION\_SSLROOTCERT**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
 -  **PATRONI\_REPLICATION\_SSLCRL**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_REPLICATION\_SSLCRLDIR**: (optional) maps to the `sslcrldir <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRLDIR>`__ connection parameter, which specifies the location of a directory with files containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_REPLICATION\_GSSENCMODE**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+-  **PATRONI\_REPLICATION\_CHANNEL\_BINDING**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
 -  **PATRONI\_SUPERUSER\_USERNAME**: name for the superuser, set during initialization (initdb) and later used by Patroni to connect to the postgres. Also this user is used by pg_rewind.
 -  **PATRONI\_SUPERUSER\_PASSWORD**: password for the superuser, set during initialization (initdb).
 -  **PATRONI\_SUPERUSER\_SSLMODE**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
 -  **PATRONI\_SUPERUSER\_SSLKEY**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+-  **PATRONI\_SUPERUSER\_SSLPASSWORD**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``PATRONI_SUPERUSER_SSLKEY``.
 -  **PATRONI\_SUPERUSER\_SSLCERT**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
 -  **PATRONI\_SUPERUSER\_SSLROOTCERT**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
 -  **PATRONI\_SUPERUSER\_SSLCRL**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_SUPERUSER\_SSLCRLDIR**: (optional) maps to the `sslcrldir <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRLDIR>`__ connection parameter, which specifies the location of a directory with files containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_SUPERUSER\_GSSENCMODE**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+-  **PATRONI\_SUPERUSER\_CHANNEL\_BINDING**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
 -  **PATRONI\_REWIND\_USERNAME**: name for the user for ``pg_rewind``; the user will be created during initialization of postgres 11+ and all necessary `permissions <https://www.postgresql.org/docs/11/app-pgrewind.html#id-1.9.5.8.8>`__ will be granted.
 -  **PATRONI\_REWIND\_PASSWORD**: password for the user for ``pg_rewind``; the user will be created during initialization.
 -  **PATRONI\_REWIND\_SSLMODE**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
 -  **PATRONI\_REWIND\_SSLKEY**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+-  **PATRONI\_REWIND\_SSLPASSWORD**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``PATRONI_REWIND_SSLKEY``.
 -  **PATRONI\_REWIND\_SSLCERT**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
 -  **PATRONI\_REWIND\_SSLROOTCERT**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
 -  **PATRONI\_REWIND\_SSLCRL**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_REWIND\_SSLCRLDIR**: (optional) maps to the `sslcrldir <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRLDIR>`__ connection parameter, which specifies the location of a directory with files containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+-  **PATRONI\_REWIND\_GSSENCMODE**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+-  **PATRONI\_REWIND\_CHANNEL\_BINDING**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
 
 REST API
 --------
@@ -125,12 +168,18 @@ REST API
 -  **PATRONI\_RESTAPI\_PASSWORD**: Basic-auth password to protect unsafe REST API endpoints.
 -  **PATRONI\_RESTAPI\_CERTFILE**: Specifies the file with the certificate in the PEM format. If the certfile is not specified or is left empty, the API server will work without SSL.
 -  **PATRONI\_RESTAPI\_KEYFILE**: Specifies the file with the secret key in the PEM format.
+-  **PATRONI\_RESTAPI\_KEYFILE\_PASSWORD**: Specifies a password for decrypting the keyfile.
 -  **PATRONI\_RESTAPI\_CAFILE**: Specifies the file with the CA_BUNDLE with certificates of trusted CAs to use while verifying client certs.
--  **PATRONI\_RESTAPI\_VERIFY\_CLIENT**: ``none``, ``optional`` or ``required``. When ``none`` REST API will not check client certificates. When ``required`` client certificates are required for all REST API calls. When ``optional`` client certificates are required for all unsafe REST API endpoints. If ``verify_client`` is set to ``optional`` or ``required`` basic-auth is not checked.
+-  **PATRONI\_RESTAPI\_CIPHERS**: (optional) Specifies the permitted cipher suites (e.g. "ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES128-GCM-SHA256:!SSLv1:!SSLv2:!SSLv3:!TLSv1:!TLSv1.1")
+-  **PATRONI\_RESTAPI\_VERIFY\_CLIENT**: ``none`` (default), ``optional`` or ``required``. When ``none`` REST API will not check client certificates. When ``required`` client certificates are required for all REST API calls. When ``optional`` client certificates are required for all unsafe REST API endpoints. When ``required`` is used, then client authentication succeeds, if the certificate signature verification succeeds. For ``optional`` the client cert will only be checked for ``PUT``, ``POST``, ``PATCH``, and ``DELETE`` requests.
+-  **PATRONI\_RESTAPI\_ALLOWLIST**: (optional): Specifies the set of hosts that are allowed to call unsafe REST API endpoints. The single element could be a host name, an IP address or a network address using CIDR notation. By default ``allow all`` is used. In case if ``allowlist`` or ``allowlist_include_members`` are set, anything that is not included is rejected.
+-  **PATRONI\_RESTAPI\_ALLOWLIST\_INCLUDE\_MEMBERS**: (optional): If set to ``true`` it allows accessing unsafe REST API endpoints from other cluster members registered in DCS (IP address or hostname is taken from the members ``api_url``). Be careful, it might happen that OS will use a different IP for outgoing connections.
+-  **PATRONI\_RESTAPI\_HTTP\_EXTRA\_HEADERS**: (optional) HTTP headers let the REST API server pass additional information with an HTTP response.
+-  **PATRONI\_RESTAPI\_HTTPS\_EXTRA\_HEADERS**: (optional) HTTPS headers let the REST API server pass additional information with an HTTP response when TLS is enabled. This will also pass additional information set in ``http_extra_headers``.
 
 CTL
 ---
--  **PATRONICTL\_CONFIG\_FILE**: location of the configuration file. 
+-  **PATRONICTL\_CONFIG\_FILE**: location of the configuration file.
 -  **PATRONI\_CTL\_INSECURE**: Allow connections to REST API without verifying SSL certs.
 -  **PATRONI\_CTL\_CACERT**: Specifies the file with the CA_BUNDLE file or directory with certificates of trusted CAs to use while verifying REST API SSL certs. If not provided patronictl will use the value provided for REST API "cafile" parameter.
 -  **PATRONI\_CTL\_CERTFILE**: Specifies the file with the client certificate in the PEM format. If not provided patronictl will use the value provided for REST API "certfile" parameter.

docs/README.rst

@@ -35,7 +35,7 @@ To install requirements on a Mac, run the following:
 
 .. _psycopg2_install_options:
 
-**Psycopg2**
+**Psycopg**
 
 Starting from `psycopg2-2.8 <http://initd.org/psycopg/articles/2019/04/04/psycopg-28-released/>`__ the binary version of psycopg2 will no longer be installed by default. Installing it from the source code requires C compiler and postgres+python dev packages.
 Since in the python world it is not possible to specify dependency as ``psycopg2 OR psycopg2-binary`` you will have to decide how to install it.
@@ -62,6 +62,12 @@ There are a few options available:
 
     pip install psycopg2>=2.5.4
 
+4. Use psycopg 3.0 instead of psycopg2
+
+::
+
+    pip install psycopg[binary]>=3.0.0
+
 **General installation for pip**
 
 Patroni can be installed with pip:
@@ -72,7 +78,7 @@ Patroni can be installed with pip:
 
 where dependencies can be either empty, or consist of one or more of the following:
 
-etcd
+etcd or etcd3
     `python-etcd` module in order to use Etcd as DCS
 consul
     `python-consul` module in order to use Consul as DCS
@@ -82,6 +88,8 @@ exhibitor
     `kazoo` module in order to use Exhibitor as DCS (same dependencies as for Zookeeper)
 kubernetes
     `kubernetes` module in order to use Kubernetes as DCS in Patroni
+raft
+    `pysyncobj` module in order to use python Raft implementation as DCS
 aws
     `boto` in order to use AWS callbacks
 
@@ -97,6 +105,13 @@ independently of Patroni.
 
 .. _running_configuring:
 
+Planning the Number of PostgreSQL Nodes
+---------------------------------------
+
+Patroni/PostgreSQL nodes are decoupled from DCS nodes (except when Patroni implements RAFT on its own) and therefore
+there is no requirement on the minimal number of nodes. Running a cluster consisting of one master and one standby is 
+perfectly fine. You can add more standby nodes later.
+
 Running and Configuring
 -----------------------
 
@@ -154,3 +169,20 @@ When connecting from an application, always use a non-superuser. Patroni require
    :target: https://travis-ci.org/zalando/patroni
 .. |Coverage Status| image:: https://coveralls.io/repos/zalando/patroni/badge.svg?branch=master
    :target: https://coveralls.io/r/zalando/patroni?branch=master
+
+Testing Your HA Solution
+--------------------------------------
+Testing an HA solution is a time consuming process, with many variables. This is particularly true considering a cross-platform application. You need a trained system administrator or a consultant to do this work. It is not something we can cover in depth in the documentation.
+
+That said, here are some pieces of your infrastructure you should be sure to test:
+
+* Network (the network in front of your system as well as the NICs [physical or virtual] themselves)
+* Disk IO 
+* file limits (nofile in Linux)
+* RAM. Even if you have oomkiller turned off as suggested, the unavailability of RAM could cause issues.
+* CPU
+* Virtualization Contention (overcommitting the hypervisor)
+* Any cgroup limitation (likely to be related to the above)
+* ``kill -9`` of any postgres process (except postmaster!). This is a decent simulation of a segfault.
+
+One thing that you should not do is run ``kill -9`` on a postmaster process. This is because doing so does not mimic any real life scenario. If you are concerned your infrastructure is insecure and an attacker could run ``kill -9``, no amount of HA process is going to fix that. The attacker will simply kill the process again, or cause chaos in another way.

docs/SETTINGS.rst

@@ -15,6 +15,7 @@ Dynamic configuration is stored in the DCS (Distributed Configuration Store) and
 -  **ttl**: the TTL to acquire the leader lock (in seconds). Think of it as the length of time before initiation of the automatic failover process. Default value: 30
 -  **retry\_timeout**: timeout for DCS and PostgreSQL operation retries (in seconds). DCS or network issues shorter than this will not cause Patroni to demote the leader. Default value: 10
 -  **maximum\_lag\_on\_failover**: the maximum bytes a follower may lag to be able to participate in leader election.
+-  **maximum\_lag\_on\_syncnode**: the maximum bytes a synchronous follower may lag before it is considered as an unhealthy candidate and swapped by healthy asynchronous follower. Patroni utilize the max replica lsn if there is more than one follower, otherwise it will use leader's current wal lsn. Default is -1, Patroni will not take action to swap synchronous unhealthy follower when the value is set to 0 or below. Please set the value high enough so Patroni won't swap synchrounous follower fequently during high transaction volume.
 -  **max\_timelines\_history**: maximum number of timeline history items kept in DCS.  Default value: 0. When set to 0, it keeps the full history in DCS.
 -  **master\_start\_timeout**: the amount of time a master is allowed to recover from failures before failover is triggered (in seconds). Default is 300 seconds. When set to 0 failover is done immediately after a crash is detected if possible. When using asynchronous replication a failover can cause lost transactions. Worst case failover time for master failure is: loop\_wait + master\_start\_timeout + loop\_wait, unless master\_start\_timeout is zero, in which case it's just loop\_wait. Set the value according to your durability/availability tradeoff.
 - **master\_stop\_timeout**: The number of seconds Patroni is allowed to wait when stopping Postgres and effective only when synchronous_mode is enabled. When set to > 0 and the synchronous_mode is enabled, Patroni sends SIGKILL to the postmaster if the stop operation is running for more than the value set by master_stop_timeout. Set the value according to your durability/availability tradeoff. If the parameter is not set or set <= 0, master_stop_timeout does not apply.
@@ -33,11 +34,37 @@ Dynamic configuration is stored in the DCS (Distributed Configuration Store) and
     -  **restore\_command**: command to restore WAL records from the remote master to standby leader, can be different from the list defined in :ref:`postgresql_settings`
     -  **archive\_cleanup\_command**: cleanup command for standby leader
     -  **recovery\_min\_apply\_delay**: how long to wait before actually apply WAL records on a standby leader
--  **slots**: define permanent replication slots. These slots will be preserved during switchover/failover. Patroni will try to create slots before opening connections to the cluster.
+-  **slots**: define permanent replication slots. These slots will be preserved during switchover/failover. The logical slots are copied from the primary to a standby with restart, and after that their position advanced every **loop_wait** seconds (if necessary). Copying logical slot files performed via ``libpq`` connection and using either rewind or superuser credentials (see **postgresql.authentication** section). There is always a chance that the logical slot position on the replica is a bit behind the former primary, therefore application should be prepared that some messages could be received the second time after the failover. The easiest way of doing so - tracking ``confirmed_flush_lsn``. Enabling permanent logical replication slots requires **postgresql.use_slots** to be set and will also automatically enable the ``hot_standby_feedback``. Since the failover of logical replication slots is unsafe on PostgreSQL 9.6 and older and PostgreSQL version 10 is missing some important functions, the feature only works with PostgreSQL 11+.
     -  **my_slot_name**: the name of replication slot. If the permanent slot name matches with the name of the current primary it will not be created. Everything else is the responsibility of the operator to make sure that there are no clashes in names between replication slots automatically created by Patroni for members and permanent replication slots.
         -  **type**: slot type. Could be ``physical`` or ``logical``. If the slot is logical, you have to additionally define ``database`` and ``plugin``.
         -  **database**: the database name where logical slots should be created.
         -  **plugin**: the plugin name for the logical slot.
+-  **ignore_slots**: list of sets of replication slot properties for which Patroni should ignore matching slots. This configuration/feature/etc. is useful when some replication slots are managed outside of Patroni. Any subset of matching properties will cause a slot to be ignored.
+    -  **name**: the name of the replication slot.
+    -  **type**: slot type. Can be ``physical`` or ``logical``. If the slot is logical, you may additionally define ``database`` and/or ``plugin``.
+    -  **database**: the database name (when matching a ``logical`` slot).
+    -  **plugin**: the logical decoding plugin (when matching a ``logical`` slot).
+
+Note: **slots** is a hashmap while **ignore_slots** is an array. For example:
+
+.. code:: YAML
+
+        slots:
+          permanent_logical_slot_name:
+            type: logical
+            database: my_db
+            plugin: test_decoding
+          permanent_physical_slot_name:
+            type: physical
+          ...
+        ignore_slots:
+          - name: ignored_logical_slot_name
+            type: logical
+            database: my_db
+            plugin: test_decoding
+          - name: ignored_physical_slot_name
+            type: physical
+          ...
 
 Global/Universal
 ----------------
@@ -63,25 +90,26 @@ Log
 
 Bootstrap configuration
 -----------------------
--  **dcs**: This section will be written into `/<namespace>/<scope>/config` of the given configuration store after initializing of new cluster. The global dynamic configuration for the cluster. Under the ``bootstrap.dcs`` you can put any of the parameters described in the :ref:`Dynamic Configuration settings <dynamic_configuration_settings>` and after Patroni initialized (bootstrapped) the new cluster, it will write this section into `/<namespace>/<scope>/config` of the configuration store. All later changes of ``bootstrap.dcs`` will not take any effect! If you want to change them please use either ``patronictl edit-config`` or Patroni :ref:`REST API <rest_api>`.
--  **method**: custom script to use for bootstrapping this cluster.
-   See :ref:`custom bootstrap methods documentation <custom_bootstrap>` for details.
-   When ``initdb`` is specified revert to the default ``initdb`` command. ``initdb`` is also triggered when no ``method``
-   parameter is present in the configuration file.
--  **initdb**: List options to be passed on to initdb.
-        -  **- data-checksums**: Must be enabled when pg_rewind is needed on 9.3.
-        -  **- encoding: UTF8**: default encoding for new databases.
-        -  **- locale: UTF8**: default locale for new databases.
--  **pg\_hba**: list of lines that you should add to pg\_hba.conf.
-        -  **- host all all 0.0.0.0/0 md5**.
-        -  **- host replication replicator 127.0.0.1/32 md5**: A line like this is required for replication.
--  **users**: Some additional users which need to be created after initializing new cluster
-    -  **admin**: the name of user
-        -  **password: zalando**:
-        -  **options**: list of options for CREATE USER statement
-            -  **- createrole**
-            -  **- createdb**
--  **post\_bootstrap** or **post\_init**: An additional script that will be executed after initializing the cluster. The script receives a connection string URL (with the cluster superuser as a user name). The PGPASSFILE variable is set to the location of pgpass file.
+-  **bootstrap**:
+    -  **dcs**: This section will be written into `/<namespace>/<scope>/config` of the given configuration store after initializing of new cluster. The global dynamic configuration for the cluster. Under the ``bootstrap.dcs`` you can put any of the parameters described in the :ref:`Dynamic Configuration settings <dynamic_configuration_settings>` and after Patroni initialized (bootstrapped) the new cluster, it will write this section into `/<namespace>/<scope>/config` of the configuration store. All later changes of ``bootstrap.dcs`` will not take any effect! If you want to change them please use either ``patronictl edit-config`` or Patroni :ref:`REST API <rest_api>`.
+    -  **method**: custom script to use for bootstrapping this cluster.
+       See :ref:`custom bootstrap methods documentation <custom_bootstrap>` for details.
+       When ``initdb`` is specified revert to the default ``initdb`` command. ``initdb`` is also triggered when no ``method``
+       parameter is present in the configuration file.
+    -  **initdb**: List options to be passed on to initdb.
+            -  **- data-checksums**: Must be enabled when pg_rewind is needed on 9.3.
+            -  **- encoding: UTF8**: default encoding for new databases.
+            -  **- locale: UTF8**: default locale for new databases.
+    -  **pg\_hba**: list of lines that you should add to pg\_hba.conf.
+            -  **- host all all 0.0.0.0/0 md5**.
+            -  **- host replication replicator 127.0.0.1/32 md5**: A line like this is required for replication.
+    -  **users**: Some additional users which need to be created after initializing new cluster
+        -  **admin**: the name of user
+            -  **password: zalando**:
+            -  **options**: list of options for CREATE USER statement
+                -  **- createrole**
+                -  **- createdb**
+    -  **post\_bootstrap** or **post\_init**: An additional script that will be executed after initializing the cluster. The script receives a connection string URL (with the cluster superuser as a user name). The PGPASSFILE variable is set to the location of pgpass file.
 
 .. _consul_settings:
 
@@ -102,8 +130,23 @@ Most of the parameters are optional, but you have to specify one of the **host**
 -  **consistency**: (optional) Select consul consistency mode. Possible values are ``default``, ``consistent``, or ``stale`` (more details in `consul API reference <https://www.consul.io/api/features/consistency.html/>`__)
 -  **checks**: (optional) list of Consul health checks used for the session. By default an empty list is used.
 -  **register\_service**: (optional) whether or not to register a service with the name defined by the scope parameter and the tag master, replica or standby-leader depending on the node's role. Defaults to **false**.
+-  **service\_tags**: (optional) additional static tags to add to the Consul service apart from the role (``master``/``replica``/``standby-leader``).  By default an empty list is used.
 -  **service\_check\_interval**: (optional) how often to perform health check against registered url.
 
+The ``token`` needs to have the following ACL permissions:
+
+::
+
+    service_prefix "${scope}" {
+        policy = "write"
+    }
+    key_prefix "${namespace}/${scope}" {
+        policy = "write"
+    }
+    session_prefix "" {
+        policy = "write"
+    }
+
 Etcd
 ----
 Most of the parameters are optional, but you have to specify one of the **host**, **hosts**, **url**, **proxy** or **srv**
@@ -113,7 +156,8 @@ Most of the parameters are optional, but you have to specify one of the **host**
 -  **use\_proxies**: If this parameter is set to true, Patroni will consider **hosts** as a list of proxies and will not perform a topology discovery of etcd cluster.
 -  **url**: url for the etcd.
 -  **proxy**: proxy url for the etcd. If you are connecting to the etcd using proxy, use this parameter instead of **url**.
--  **srv**: Domain to search the SRV record(s) for cluster autodiscovery.
+-  **srv**: Domain to search the SRV record(s) for cluster autodiscovery. Patroni will try to query these SRV service names for specified domain (in that order until first success): ``_etcd-client-ssl``, ``_etcd-client``, ``_etcd-ssl``, ``_etcd``, ``_etcd-server-ssl``, ``_etcd-server``. If SRV records for ``_etcd-server-ssl`` or ``_etcd-server`` are retrieved then ETCD peer protocol is used do query ETCD for available members. Otherwise hosts from SRV records will be used.
+-  **srv\_suffix**: Configures a suffix to the SRV name that is queried during discovery. Use this flag to differentiate between multiple etcd clusters under the same domain. Works only with conjunction with **srv**. For example, if ``srv_suffix: foo`` and ``srv: example.org`` are set, the following DNS SRV query is made:``_etcd-client-ssl-foo._tcp.example.com`` (and so on for every possible ETCD SRV service name).
 -  **protocol**: (optional) http or https, if not specified http is used. If the **url** or **proxy** is specified - will take protocol from them.
 -  **username**: (optional) username for etcd authentication.
 -  **password**: (optional) password for etcd authentication.
@@ -121,9 +165,28 @@ Most of the parameters are optional, but you have to specify one of the **host**
 -  **cert**: (optional) file with the client certificate.
 -  **key**: (optional) file with the client key. Can be empty if the key is part of **cert**.
 
+Etcdv3
+------
+If you want that Patroni works with Etcd cluster via protocol version 3, you need to use the ``etcd3`` section in the Patroni configuration file. All configuration parameters are the same as for ``etcd``.
+
+.. warning::
+    Keys created with protocol version 2 are not visible with protocol version 3 and the other way around, therefore it is not possible to switch from ``etcd`` to ``etcd3`` just by updating Patroni config file.
+
+
 ZooKeeper
 ----------
--  **hosts**: list of ZooKeeper cluster members in format: ['host1:port1', 'host2:port2', 'etc...'].
+-  **hosts**: List of ZooKeeper cluster members in format: ['host1:port1', 'host2:port2', 'etc...'].
+-  **use_ssl**: (optional) Whether SSL is used or not. Defaults to ``false``. If set to ``false``, all SSL specific parameters are ignored.
+-  **cacert**: (optional) The CA certificate. If present it will enable validation.
+-  **cert**: (optional) File with the client certificate.
+-  **key**: (optional) File with the client key.
+-  **key_password**: (optional) The client key password.
+-  **verify**: (optional) Whether to verify certificate or not. Defaults to ``true``.
+-  **set_acls**: (optional) If set, configure Kazoo to apply a default ACL to each ZNode that it creates. ACLs will assume 'x509' schema and should be specified as a dictionary with the principal as the key and one or more permissions as a list in the value.  Permissions may be one of ``CREATE``, ``READ``, ``WRITE``, ``DELETE`` or ``ADMIN``.  For example, ``set_acls: {CN=principal1: [CREATE, READ], CN=principal2: [ALL]}``. 
+
+.. note::
+    It is required to install ``kazoo>=2.6.0`` to support SSL.
+
 
 Exhibitor
 ---------
@@ -135,6 +198,7 @@ Exhibitor
 
 Kubernetes
 ----------
+-  **bypass\_api\_service**: (optional) When communicating with the Kubernetes API, Patroni is usually relying on the `kubernetes` service, the address of which is exposed in the pods via the `KUBERNETES_SERVICE_HOST` environment variable. If `bypass_api_service` is set to ``true``, Patroni will resolve the list of API nodes behind the service and connect directly to them.
 -  **namespace**: (optional) Kubernetes namespace where Patroni pod is running. Default value is `default`.
 -  **labels**: Labels in format ``{label1: value1, label2: value2}``. These labels will be used to find existing objects (Pods and either Endpoints or ConfigMaps) associated with the current cluster. Also Patroni will set them on every object (Endpoint or ConfigMap) it creates.
 -  **scope\_label**: (optional) name of the label containing cluster name. Default value is `cluster-name`.
@@ -142,88 +206,163 @@ Kubernetes
 -  **use\_endpoints**: (optional) if set to true, Patroni will use Endpoints instead of ConfigMaps to run leader elections and keep cluster state.
 -  **pod\_ip**: (optional) IP address of the pod Patroni is running in. This value is required when `use_endpoints` is enabled and is used to populate the leader endpoint subsets when the pod's PostgreSQL is promoted.
 -  **ports**: (optional) if the Service object has the name for the port, the same name must appear in the Endpoint object, otherwise service won't work. For example, if your service is defined as ``{Kind: Service, spec: {ports: [{name: postgresql, port: 5432, targetPort: 5432}]}}``, then you have to set ``kubernetes.ports: [{"name": "postgresql", "port": 5432}]`` and Patroni will use it for updating subsets of the leader Endpoint. This parameter is used only if `kubernetes.use_endpoints` is set.
+-  **cacert**: (optional) Specifies the file with the CA_BUNDLE file with certificates of trusted CAs to use while verifying Kubernetes API SSL certs. If not provided, patroni will use the value provided by the ServiceAccount secret.
+
+
+.. _raft_settings:
+
+Raft
+----
+-  **self\_addr**: ``ip:port`` to listen on for Raft connections. The ``self_addr`` must be accessible from other nodes of the cluster. If not set, the node will not participate in consensus.
+-  **bind\_addr**: (optional) ``ip:port`` to listen on for Raft connections. If not specified the ``self_addr`` will be used.
+-  **partner\_addrs**: list of other Patroni nodes in the cluster in format: ['ip1:port', 'ip2:port', 'etc...']
+-  **data\_dir**: directory where to store Raft log and snapshot. If not specified the current working directory is used.
+-  **password**: (optional) Encrypt Raft traffic with a specified password, requires ``cryptography`` python module.
+
+  Short FAQ about Raft implementation
+
+  - Q: How to list all the nodes providing consensus?
+
+    A: ``syncobj_admin -conn host:port`` -status where the host:port is the address of one of the cluster nodes
+
+  - Q: Node that was a part of consensus and has gone and I can't reuse the same IP for other node. How to remove this node from the consensus?
+
+    A: ``syncobj_admin -conn host:port -remove host2:port2`` where the ``host2:port2`` is the address of the node you want to remove from consensus.
+
+  - Q: Where to get the ``syncobj_admin`` utility?
+
+    A: It is installed together with ``pysyncobj`` module (python RAFT implementation), which is Patroni dependency.
+
+  - Q: it is possible to run Patroni node without adding in to the consensus?
+
+    A: Yes, just comment out or remove ``raft.self_addr`` from Patroni configuration.
+
+  - Q: It is possible to run Patroni and PostgreSQL only on two nodes?
+
+    A: Yes, on the third node you can run ``patroni_raft_controller`` (without Patroni and PostgreSQL). In such a setup, one can temporarily lose one node without affecting the primary.
+
 
 .. _postgresql_settings:
 
 PostgreSQL
 ----------
--  **authentication**:
-    -  **superuser**:
-        -  **username**: name for the superuser, set during initialization (initdb) and later used by Patroni to connect to the postgres.
-        -  **password**: password for the superuser, set during initialization (initdb).
-        -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
-        -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
-        -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
-        -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
-        -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
-    -  **replication**:
-        -  **username**: replication username; the user will be created during initialization. Replicas will use this user to access master via streaming replication
-        -  **password**: replication password; the user will be created during initialization.
-        -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
-        -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
-        -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
-        -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
-        -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
-    -  **rewind**:
-        -  **username**: name for the user for ``pg_rewind``; the user will be created during initialization of postgres 11+ and all necessary `permissions <https://www.postgresql.org/docs/11/app-pgrewind.html#id-1.9.5.8.8>`__ will be granted.
-        -  **password**: password for the user for ``pg_rewind``; the user will be created during initialization.
-        -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
-        -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
-        -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
-        -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
-        -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
--  **callbacks**: callback scripts to run on certain actions. Patroni will pass the action, role and cluster name. (See scripts/aws.py as an example of how to write them.)
-        -  **on\_reload**: run this script when configuration reload is triggered.
-        -  **on\_restart**: run this script when the postgres restarts (without changing role).
-        -  **on\_role\_change**: run this script when the postgres is being promoted or demoted.
-        -  **on\_start**: run this script when the postgres starts.
-        -  **on\_stop**: run this script when the postgres stops.
--  **connect\_address**: IP address + port through which Postgres is accessible from other nodes and applications.
--  **create\_replica\_methods**: an ordered list of the create methods for turning a Patroni node into a new replica.
-   "basebackup" is the default method; other methods are assumed to refer to scripts, each of which is configured as its
-   own config item. See :ref:`custom replica creation methods documentation <custom_replica_creation>` for further explanation.
--  **data\_dir**: The location of the Postgres data directory, either :ref:`existing <existing_data>` or to be initialized by Patroni.
--  **config\_dir**: The location of the Postgres configuration directory, defaults to the data directory. Must be writable by Patroni.
--  **bin\_dir**: Path to PostgreSQL binaries (pg_ctl, pg_rewind, pg_basebackup, postgres). The default value is an empty string meaning that PATH environment variable will be used to find the executables.
--  **listen**: IP address + port that Postgres listens to; must be accessible from other nodes in the cluster, if you're using streaming replication. Multiple comma-separated addresses are permitted, as long as the port component is appended after to the last one with a colon, i.e. ``listen: 127.0.0.1,127.0.0.2:5432``. Patroni will use the first address from this list to establish local connections to the PostgreSQL node.
--  **use\_unix\_socket**: specifies that Patroni should prefer to use unix sockets to connect to the cluster. Default value is ``false``. If ``unix_socket_directories`` is defined, Patroni will use the first suitable value from it to connect to the cluster and fallback to tcp if nothing is suitable. If ``unix_socket_directories`` is not specified in ``postgresql.parameters``, Patroni will assume that the default value should be used and omit ``host`` from the connection parameters.
--  **pgpass**: path to the `.pgpass <https://www.postgresql.org/docs/current/static/libpq-pgpass.html>`__ password file. Patroni creates this file before executing pg\_basebackup, the post_init script and under some other circumstances. The location must be writable by Patroni.
--  **recovery\_conf**: additional configuration settings written to recovery.conf when configuring follower.
--  **custom\_conf** : path to an optional custom ``postgresql.conf`` file, that will be used in place of ``postgresql.base.conf``. The file must exist on all cluster nodes, be readable by PostgreSQL and will be included from its location on the real ``postgresql.conf``. Note that Patroni will not monitor this file for changes, nor backup it. However, its settings can still be overridden by Patroni's own configuration facilities - see :ref:`dynamic configuration <dynamic_configuration>` for details.
--  **parameters**: list of configuration settings for Postgres. Many of these are required for replication to work.
--  **pg\_hba**: list of lines that Patroni will use to generate ``pg_hba.conf``. This parameter has higher priority than ``bootstrap.pg_hba``. Together with :ref:`dynamic configuration <dynamic_configuration>` it simplifies management of ``pg_hba.conf``.
-        -  **- host all all 0.0.0.0/0 md5**.
-        -  **- host replication replicator 127.0.0.1/32 md5**: A line like this is required for replication.
--  **pg\_ident**: list of lines that Patroni will use to generate ``pg_ident.conf``. Together with :ref:`dynamic configuration <dynamic_configuration>` it simplifies management of ``pg_ident.conf``.
-        -  **- mapname1 systemname1 pguser1**.
-        -  **- mapname1 systemname2 pguser2**.
--  **pg\_ctl\_timeout**: How long should pg_ctl wait when doing ``start``, ``stop`` or ``restart``. Default value is 60 seconds.
--  **use\_pg\_rewind**: try to use pg\_rewind on the former leader when it joins cluster as a replica.
--  **remove\_data\_directory\_on\_rewind\_failure**: If this option is enabled, Patroni will remove the PostgreSQL data directory and recreate the replica. Otherwise it will try to follow the new leader. Default value is **false**.
--  **remove\_data\_directory\_on\_diverged\_timelines**: Patroni will remove the PostgreSQL data directory and recreate the replica if it notices that timelines are diverging and the former master can not start streaming from the new master. This option is useful when ``pg_rewind`` can not be used. Default value is **false**.
--  **replica\_method**: for each create_replica_methods other than basebackup, you would add a configuration section of the same name. At a minimum, this should include "command" with a full path to the actual script to be executed. Other configuration parameters will be passed along to the script in the form "parameter=value".
+-  **postgresql**:
+    -  **authentication**:
+        -  **superuser**:
+            -  **username**: name for the superuser, set during initialization (initdb) and later used by Patroni to connect to the postgres.
+            -  **password**: password for the superuser, set during initialization (initdb).
+            -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
+            -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+            -  **sslpassword**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``sslkey``.
+            -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
+            -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
+            -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+            -  **sslcrldir**: (optional) maps to the `sslcrldir <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRLDIR>`__ connection parameter, which specifies the location of a directory with files containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+            -  **gssencmode**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+            -  **channel_binding**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
+        -  **replication**:
+            -  **username**: replication username; the user will be created during initialization. Replicas will use this user to access master via streaming replication
+            -  **password**: replication password; the user will be created during initialization.
+            -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
+            -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+            -  **sslpassword**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``sslkey``.
+            -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
+            -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
+            -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+            -  **sslcrldir**: (optional) maps to the `sslcrldir <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRLDIR>`__ connection parameter, which specifies the location of a directory with files containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+            -  **gssencmode**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+            -  **channel_binding**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
+        -  **rewind**:
+            -  **username**: name for the user for ``pg_rewind``; the user will be created during initialization of postgres 11+ and all necessary `permissions <https://www.postgresql.org/docs/11/app-pgrewind.html#id-1.9.5.8.8>`__ will be granted.
+            -  **password**: password for the user for ``pg_rewind``; the user will be created during initialization.
+            -  **sslmode**: (optional) maps to the `sslmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLMODE>`__ connection parameter, which allows a client to specify the type of TLS negotiation mode with the server. For more information on how each mode works, please visit the `PostgreSQL documentation <https://www.postgresql.org/docs/current/libpq-ssl.html#LIBPQ-SSL-SSLMODE-STATEMENTS>`__. The default mode is ``prefer``.
+            -  **sslkey**: (optional) maps to the `sslkey <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLKEY>`__ connection parameter, which specifies the location of the secret key used with the client's certificate.
+            -  **sslpassword**: (optional) maps to the `sslpassword <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLPASSWORD>`__ connection parameter, which specifies the password for the secret key specified in ``sslkey``.
+            -  **sslcert**: (optional) maps to the `sslcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCERT>`__ connection parameter, which specifies the location of the client certificate.
+            -  **sslrootcert**: (optional) maps to the `sslrootcert <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLROOTCERT>`__ connection parameter, which specifies the location of a file containing one ore more certificate authorities (CA) certificates that the client will use to verify a server's certificate.
+            -  **sslcrl**: (optional) maps to the `sslcrl <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRL>`__ connection parameter, which specifies the location of a file containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+            -  **sslcrldir**: (optional) maps to the `sslcrldir <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-SSLCRLDIR>`__ connection parameter, which specifies the location of a directory with files containing a certificate revocation list. A client will reject connecting to any server that has a certificate present in this list.
+            -  **gssencmode**: (optional) maps to the `gssencmode <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-GSSENCMODE>`__ connection parameter, which determines whether or with what priority a secure GSS TCP/IP connection will be negotiated with the server
+            -  **channel_binding**: (optional) maps to the `channel_binding <https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNECT-CHANNEL-BINDING>`__ connection parameter, which controls the client's use of channel binding.
+    -  **callbacks**: callback scripts to run on certain actions. Patroni will pass the action, role and cluster name. (See scripts/aws.py as an example of how to write them.)
+            -  **on\_reload**: run this script when configuration reload is triggered.
+            -  **on\_restart**: run this script when the postgres restarts (without changing role).
+            -  **on\_role\_change**: run this script when the postgres is being promoted or demoted.
+            -  **on\_start**: run this script when the postgres starts.
+            -  **on\_stop**: run this script when the postgres stops.
+    -  **connect\_address**: IP address + port through which Postgres is accessible from other nodes and applications.
+    -  **create\_replica\_methods**: an ordered list of the create methods for turning a Patroni node into a new replica.
+       "basebackup" is the default method; other methods are assumed to refer to scripts, each of which is configured as its
+       own config item. See :ref:`custom replica creation methods documentation <custom_replica_creation>` for further explanation.
+    -  **data\_dir**: The location of the Postgres data directory, either :ref:`existing <existing_data>` or to be initialized by Patroni.
+    -  **config\_dir**: The location of the Postgres configuration directory, defaults to the data directory. Must be writable by Patroni.
+    -  **bin\_dir**: Path to PostgreSQL binaries (pg_ctl, pg_rewind, pg_basebackup, postgres). The default value is an empty string meaning that PATH environment variable will be used to find the executables.
+    -  **listen**: IP address + port that Postgres listens to; must be accessible from other nodes in the cluster, if you're using streaming replication. Multiple comma-separated addresses are permitted, as long as the port component is appended after to the last one with a colon, i.e. ``listen: 127.0.0.1,127.0.0.2:5432``. Patroni will use the first address from this list to establish local connections to the PostgreSQL node.
+    -  **use\_unix\_socket**: specifies that Patroni should prefer to use unix sockets to connect to the cluster. Default value is ``false``. If ``unix_socket_directories`` is defined, Patroni will use the first suitable value from it to connect to the cluster and fallback to tcp if nothing is suitable. If ``unix_socket_directories`` is not specified in ``postgresql.parameters``, Patroni will assume that the default value should be used and omit ``host`` from the connection parameters.
+    -  **use\_unix\_socket\_repl**: specifies that Patroni should prefer to use unix sockets for replication user cluster connection. Default value is ``false``. If ``unix_socket_directories`` is defined, Patroni will use the first suitable value from it to connect to the cluster and fallback to tcp if nothing is suitable. If ``unix_socket_directories`` is not specified in ``postgresql.parameters``, Patroni will assume that the default value should be used and omit ``host`` from the connection parameters.
+    -  **pgpass**: path to the `.pgpass <https://www.postgresql.org/docs/current/static/libpq-pgpass.html>`__ password file. Patroni creates this file before executing pg\_basebackup, the post_init script and under some other circumstances. The location must be writable by Patroni.
+    -  **recovery\_conf**: additional configuration settings written to recovery.conf when configuring follower.
+    -  **custom\_conf** : path to an optional custom ``postgresql.conf`` file, that will be used in place of ``postgresql.base.conf``. The file must exist on all cluster nodes, be readable by PostgreSQL and will be included from its location on the real ``postgresql.conf``. Note that Patroni will not monitor this file for changes, nor backup it. However, its settings can still be overridden by Patroni's own configuration facilities - see :ref:`dynamic configuration <dynamic_configuration>` for details.
+    -  **parameters**: list of configuration settings for Postgres. Many of these are required for replication to work.
+    -  **pg\_hba**: list of lines that Patroni will use to generate ``pg_hba.conf``. This parameter has higher priority than ``bootstrap.pg_hba``. Together with :ref:`dynamic configuration <dynamic_configuration>` it simplifies management of ``pg_hba.conf``.
+            -  **- host all all 0.0.0.0/0 md5**.
+            -  **- host replication replicator 127.0.0.1/32 md5**: A line like this is required for replication.
+    -  **pg\_ident**: list of lines that Patroni will use to generate ``pg_ident.conf``. Together with :ref:`dynamic configuration <dynamic_configuration>` it simplifies management of ``pg_ident.conf``.
+            -  **- mapname1 systemname1 pguser1**.
+            -  **- mapname1 systemname2 pguser2**.
+    -  **pg\_ctl\_timeout**: How long should pg_ctl wait when doing ``start``, ``stop`` or ``restart``. Default value is 60 seconds.
+    -  **use\_pg\_rewind**: try to use pg\_rewind on the former leader when it joins cluster as a replica.
+    -  **remove\_data\_directory\_on\_rewind\_failure**: If this option is enabled, Patroni will remove the PostgreSQL data directory and recreate the replica. Otherwise it will try to follow the new leader. Default value is **false**.
+    -  **remove\_data\_directory\_on\_diverged\_timelines**: Patroni will remove the PostgreSQL data directory and recreate the replica if it notices that timelines are diverging and the former master can not start streaming from the new master. This option is useful when ``pg_rewind`` can not be used. Default value is **false**.
+    -  **replica\_method**: for each create_replica_methods other than basebackup, you would add a configuration section of the same name. At a minimum, this should include "command" with a full path to the actual script to be executed. Other configuration parameters will be passed along to the script in the form "parameter=value".
+    -  **pre\_promote**: a fencing script that executes during a failover after acquiring the leader lock but before promoting the replica. If the script exits with a non-zero code, Patroni does not promote the replica and removes the leader key from DCS.
 
 REST API
 --------
--  **connect\_address**: IP address (or hostname) and port, to access the Patroni's :ref:`REST API <rest_api>`. All the members of the cluster must be able to connect to this address, so unless the Patroni setup is intended for a demo inside the localhost, this address must be a non "localhost" or loopback address (ie: "localhost" or "127.0.0.1"). It can serve as an endpoint for HTTP health checks (read below about the "listen" REST API parameter), and also for user queries (either directly or via the REST API), as well as for the health checks done by the cluster members during leader elections (for example, to determine whether the master is still running, or if there is a node which has a WAL position that is ahead of the one doing the query; etc.) The connect_address is put in the member key in DCS, making it possible to translate the member name into the address to connect to its REST API.
+-  **restapi**:
+        -  **connect\_address**: IP address (or hostname) and port, to access the Patroni's :ref:`REST API <rest_api>`. All the members of the cluster must be able to connect to this address, so unless the Patroni setup is intended for a demo inside the localhost, this address must be a non "localhost" or loopback address (ie: "localhost" or "127.0.0.1"). It can serve as an endpoint for HTTP health checks (read below about the "listen" REST API parameter), and also for user queries (either directly or via the REST API), as well as for the health checks done by the cluster members during leader elections (for example, to determine whether the master is still running, or if there is a node which has a WAL position that is ahead of the one doing the query; etc.) The connect_address is put in the member key in DCS, making it possible to translate the member name into the address to connect to its REST API.
 
--  **listen**: IP address (or hostname) and port that Patroni will listen to for the REST API - to provide also the same health checks and cluster messaging between the participating nodes, as described above. to provide health-check information for HAProxy (or any other load balancer capable of doing a HTTP "OPTION" or "GET" checks).
+        -  **listen**: IP address (or hostname) and port that Patroni will listen to for the REST API - to provide also the same health checks and cluster messaging between the participating nodes, as described above. to provide health-check information for HAProxy (or any other load balancer capable of doing a HTTP "OPTION" or "GET" checks).
 
--  **Optional**:
-        -  **authentication**:
+        -  **authentication**: (optional)
             -  **username**: Basic-auth username to protect unsafe REST API endpoints.
             -  **password**: Basic-auth password to protect unsafe REST API endpoints.
+        -  **certfile**: (optional): Specifies the file with the certificate in the PEM format. If the certfile is not specified or is left empty, the API server will work without SSL.
+        -  **keyfile**: (optional): Specifies the file with the secret key in the PEM format.
+        -  **keyfile_password**: (optional): Specifies a password for decrypting the keyfile.
+        -  **cafile**: (optional): Specifies the file with the CA_BUNDLE with certificates of trusted CAs to use while verifying client certs.
+        -  **ciphers**: (optional): Specifies the permitted cipher suites (e.g. "ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES128-GCM-SHA256:!SSLv1:!SSLv2:!SSLv3:!TLSv1:!TLSv1.1")
+        -  **verify\_client**: (optional): ``none`` (default), ``optional`` or ``required``. When ``none`` REST API will not check client certificates. When ``required`` client certificates are required for all REST API calls. When ``optional`` client certificates are required for all unsafe REST API endpoints. When ``required`` is used, then client authentication succeeds, if the certificate signature verification succeeds.  For ``optional`` the client cert will only be checked for ``PUT``, ``POST``, ``PATCH``, and ``DELETE`` requests.
+        -  **allowlist**: (optional): Specifies the set of hosts that are allowed to call unsafe REST API endpoints. The single element could be a host name, an IP address or a network address using CIDR notation. By default ``allow all`` is used. In case if ``allowlist`` or ``allowlist_include_members`` are set, anything that is not included is rejected.
+        -  **allowlist\_include\_members**: (optional): If set to ``true`` it allows accessing unsafe REST API endpoints from other cluster members registered in DCS (IP address or hostname is taken from the members ``api_url``). Be careful, it might happen that OS will use a different IP for outgoing connections.
+        -  **http\_extra\_headers**: (optional): HTTP headers let the REST API server pass additional information with an HTTP response.
+        -  **https\_extra\_headers**: (optional): HTTPS headers let the REST API server pass additional information with an HTTP response when TLS is enabled. This will also pass additional information set in ``http_extra_headers``.
 
-        -  **certfile**: Specifies the file with the certificate in the PEM format. If the certfile is not specified or is left empty, the API server will work without SSL.
-        -  **keyfile**: Specifies the file with the secret key in the PEM format.
-        -  **cafile**: Specifies the file with the CA_BUNDLE with certificates of trusted CAs to use while verifying client certs.
-        -  **verify\_client**: ``none``, ``optional`` or ``required``. When ``none`` REST API will not check client certificates. When ``required`` client certificates are required for all REST API calls. When ``optional`` client certificates are required for all unsafe REST API endpoints. If ``verify_client`` is set to ``optional`` or ``required`` basic-auth is not checked.
+Here is an example of both **http_extra_headers** and **https_extra_headers**:
+
+.. code:: YAML
+
+        restapi:
+          listen: <listen>
+          connect_address: <connect_address>
+          authentication:
+            username: <username>
+            password: <password>
+          http_extra_headers:
+            'X-Frame-Options': 'SAMEORIGIN'
+            'X-XSS-Protection': '1; mode=block'
+            'X-Content-Type-Options': 'nosniff'
+          cafile: <ca file>
+          certfile: <cert>
+          keyfile: <key>
+          https_extra_headers:
+            'Strict-Transport-Security': 'max-age=31536000; includeSubDomains'
 
 .. _patronictl_settings:
 
 CTL
 ---
--  **Optional**:
+- **ctl**: (optional)
     -  **insecure**: Allow connections to REST API without verifying SSL certs.
     -  **cacert**: Specifies the file with the CA_BUNDLE file or directory with certificates of trusted CAs to use while verifying REST API SSL certs. If not provided patronictl will use the value provided for REST API "cafile" parameter.
     -  **certfile**: Specifies the file with the client certificate in the PEM format. If not provided patronictl will use the value provided for REST API "certfile" parameter.
@@ -235,6 +374,8 @@ Watchdog
 - **device**: Path to watchdog device. Defaults to ``/dev/watchdog``.
 - **safety_margin**: Number of seconds of safety margin between watchdog triggering and leader key expiration.
 
+.. _tags_settings:
+
 Tags
 ----
 - **nofailover**: ``true`` or ``false``, controls whether this node is allowed to participate in the leader race and become a leader. Defaults to ``false``
@@ -242,3 +383,12 @@ Tags
 - **noloadbalance**: ``true`` or ``false``. If set to ``true`` the node will return HTTP Status Code 503 for the ``GET /replica`` REST API health-check and therefore will be excluded from the load-balancing. Defaults to ``false``.
 - **replicatefrom**: The IP address/hostname of another replica. Used to support cascading replication.
 - **nosync**: ``true`` or ``false``. If set to ``true`` the node will never be selected as a synchronous replica.
+
+In addition to these predefined tags, you can also add your own ones:
+
+- **key1**: ``true``
+- **key2**: ``false``
+- **key3**: ``1.4``
+- **key4**: ``"RandomString"``
+
+Tags are visible in the :ref:`REST API <rest_api>` and ``patronictl list`` You can also check for an instance health using these tags. If the tag isn't defined for an instance, or if the respective value doesn't match the querying value, it will return HTTP Status Code 503.

docs/conf.py

@@ -194,4 +194,7 @@ intersphinx_mapping = {'https://docs.python.org/': None}
 # A possibility to have an own stylesheet, to add new rules or override existing ones
 # For the latter case, the CSS specificity of the rules should be higher than the default ones
 def setup(app):
-   app.add_stylesheet("custom.css")
+    if hasattr(app, 'add_css_file'):
+        app.add_css_file('custom.css')
+    else:
+        app.add_stylesheet('custom.css')

docs/dynamic_configuration.rst

@@ -20,6 +20,8 @@ Patroni configuration is stored in the DCS (Distributed Configuration Store). Th
 	It is possible to set/override some of the "Local" configuration parameters with environment variables.
 	Environment configuration is very useful when you are running in a dynamic environment and you don't know some of the parameters in advance (for example it's not possible to know your external IP address when you are running inside ``docker``).
 
+The local configuration can be either a single YAML file or a directory. When it is a directory, all YAML files in that directory are loaded one by one in sorted order. In case a key is defined in multiple files, the occurrence in the last file takes precedence.
+
 Some of the PostgreSQL parameters must hold the same values on the master and the replicas. For those, values set either in the local patroni configuration files or via the environment variables take no effect. To alter or set their values one must change the shared configuration in the DCS. Below is the actual list of such parameters together with the default values:
 
 - max_connections: 100
@@ -35,6 +37,7 @@ For the parameters below, PostgreSQL does not require equal values among the mas
 - max_wal_senders: 5
 - max_replication_slots: 5
 - wal_keep_segments: 8
+- wal_keep_size: 128MB
 
 These parameters are validated to ensure they are sane, or meet a minimum value.
 

docs/existing_data.rst

@@ -23,6 +23,21 @@ A Patroni cluster can be started with a data directory from a single-node Postgr
 3. Start Patroni (e.g. ``patroni /etc/patroni/patroni.yml``). It automatically detects that PostgreSQL daemon is already running but its configuration might be out-of-date.
 4. Ask Patroni to restart the node with ``patronictl restart cluster-name node-name``. This step is only required if PostgreSQL configuration is out-of-date.
 
+Major Upgrade of PostgreSQL Version
+===================================
+
+The only possible way to do a major upgrade currently is:
+
+1. Stop Patroni
+2. Upgrade PostgreSQL binaries and perform `pg_upgrade <https://www.postgresql.org/docs/current/pgupgrade.html>`_ on the master node
+3. Update patroni.yml
+4. Remove the initialize key from DCS or wipe complete cluster state from DCS. The second one could be achieved by running ``patronictl remove <cluster-name>``. It is necessary because pg_upgrade runs initdb which actually creates a new database with a new PostgreSQL system identifier.
+5. If you wiped the cluster state in the previous step, you may wish to copy patroni.dynamic.json from old data dir to the new one.  It will help you to retain some PostgreSQL parameters you had set before.
+6. Start Patroni on the master node.
+7. Upgrade PostgreSQL binaries, update patroni.yml and wipe the data_dir on standby nodes.
+8. Start Patroni on the standby nodes and wait for the replication to complete.
+
+Running pg_upgrade on standby nodes is not supported by PostgreSQL. If you know what you are doing, you can try the rsync procedure described in https://www.postgresql.org/docs/current/pgupgrade.html instead of wiping data_dir on standby nodes. The safest way is however to let Patroni replicate the data for you.
 
 FAQ
 ---

docs/index.rst

@@ -10,6 +10,8 @@ Patroni is a template for you to create your own customized, high-availability s
 
 We call Patroni a "template" because it is far from being a one-size-fits-all or plug-and-play replication system. It will have its own caveats. Use wisely. There are many ways to run high availability with PostgreSQL; for a list, see the `PostgreSQL Documentation <https://wiki.postgresql.org/wiki/Replication,_Clustering,_and_Connection_Pooling>`__.
 
+Currently supported PostgreSQL versions: 9.3 to 14.
+
 **Note to Kubernetes users**: Patroni can run natively on top of Kubernetes. Take a look at the :ref:`Kubernetes <kubernetes>` chapter of the Patroni documentation.
 
 
@@ -20,8 +22,10 @@ We call Patroni a "template" because it is far from being a one-size-fits-all or
    README
    dynamic_configuration
    rest_api
+   existing_data
    ENVIRONMENT
    SETTINGS
+   security
    replica_bootstrap
    replication_modes
    pause

docs/releases.rst

@@ -3,6 +3,604 @@
 Release notes
 =============
 
+Version 2.1.2
+-------------
+
+**New features**
+
+- Compatibility with ``psycopg>=3.0`` (Alexander Kukushkin)
+
+  By default ``psycopg2`` is preferred. `psycopg>=3.0` will be used only if ``psycopg2`` is not available or its version is too old.
+
+- Add ``dcs_last_seen`` field to the REST API (Michael Banck)
+
+  This field notes the last time (as unix epoch) a cluster member has successfully communicated with the DCS. This is useful to identify and/or analyze network partitions.
+
+- Release the leader lock when ``pg_controldata`` reports "shut down" (Alexander)
+
+  To solve the problem of slow switchover/shutdown in case ``archive_command`` is slow/failing, Patroni will remove the leader key immediately after ``pg_controldata`` started reporting PGDATA as ``shut down`` cleanly and it verified that there is at least one replica that received all changes. If there are no replicas that fulfill this condition the leader key is not removed and the old behavior is retained, i.e. Patroni will keep updating the lock.
+
+- Add ``sslcrldir`` connection parameter support (Kostiantyn Nemchenko)
+
+  The new connection parameter was introduced in the PostgreSQL v14.
+
+- Allow setting ACLs for ZNodes in Zookeeper (Alwyn Davis)
+
+  Introduce a new configuration option ``zookeeper.set_acls`` so that Kazoo will apply a default ACL for each ZNode that it creates.
+
+
+**Stability improvements**
+
+- Delay the next attempt of recovery till next HA loop (Alexander)
+
+  If Postgres crashed due to out of disk space (for example) and fails to start because of that Patroni is too eagerly trying to recover it flooding logs.
+
+- Add log before demoting, which can take some time (Michael)
+
+  It can take some time for the demote to finish and it might not be obvious from looking at the logs what exactly is going on.
+
+- Improve "I am" status messages (Michael)
+
+  ``no action. I am a secondary ({0})`` vs ``no action. I am ({0}), a secondary``
+
+- Cast to int ``wal_keep_segments`` when converting to ``wal_keep_size`` (Jorge Solórzano)
+
+  It is possible to specify ``wal_keep_segments`` as a string in the global :ref:`dynamic configuration <dynamic_configuration>` and due to Python being a dynamically typed language the string was simply multiplied. Example: ``wal_keep_segments: "100"`` was converted to ``100100100100100100100100100100100100100100100100MB``.
+
+- Allow switchover only to sync nodes when synchronous replication is enabled (Alexander)
+
+  In addition to that do the leader race only against known synchronous nodes.
+
+- Use cached role as a fallback when Postgres is slow (Alexander)
+
+  In some extreme cases Postgres could be so slow that the normal monitoring query does not finish in a few seconds. The ``statement_timeout`` exception not being properly handled could lead to the situation where Postgres was not demoted on time when the leader key expired or the update failed. In case of such exception Patroni will use the cached ``role`` to determine whether Postgres is running as a primary.
+
+- Avoid unnecessary updates of the member ZNode (Alexander)
+
+  If no values have changed in the members data, the update should not happen.
+
+- Optimize checkpoint after promote (Alexander)
+
+  Avoid doing ``CHECKPOINT`` if the latest timeline is already stored in ``pg_control``. It helps to avoid unnecessary ``CHECKPOINT`` right after initializing the new cluster with ``initdb``.
+
+- Prefer members without ``nofailover`` when picking sync nodes (Alexander)
+
+  Previously sync nodes were selected only based on the replication lag, hence the node with ``nofailover`` tag had the same chances to become synchronous as any other node. That behavior was confusing and dangerous at the same time because in case of a failed primary the failover could not happen automatically.
+
+- Remove duplicate hosts from the etcd machine cache (Michael)
+
+  Advertised client URLs in the etcd cluster could be misconfigured. Removing duplicates in Patroni in this case is a low-hanging fruit.
+
+
+**Bugfixes**
+
+- Skip temporary replication slots while doing slot management (Alexander)
+
+  Starting from v10 ``pg_basebackup`` creates a temporary replication slot for WAL streaming and Patroni was trying to drop it because the slot name looks unknown. In order to fix it, we skip all temporary slots when querying ``pg_stat_replication_slots`` view.
+
+- Ensure ``pg_replication_slot_advance()`` doesn't timeout (Alexander)
+
+  Patroni was using the default ``statement_timeout`` in this case and once the call failed there are very high chances that it will never recover, resulting in increased size of ``pg_wal`` and ``pg_catalog`` bloat.
+
+- The ``/status`` wasn't updated on demote (Alexander)
+
+  After demoting PostgreSQL the old leader updates the last LSN in DCS. Starting from ``2.1.0`` the new ``/status`` key was introduced, but the optime was still written to the ``/optime/leader``.
+
+- Handle DCS exceptions when demoting (Alexander)
+
+  While demoting the master due to failure to update the leader lock it could happen that DCS goes completely down and the ``get_cluster()`` call raises an exception. Not being handled properly it results in Postgres remaining stopped until DCS recovers.
+
+- The ``use_unix_socket_repl`` didn't work is some cases (Alexander)
+
+  Specifically, if ``postgresql.unix_socket_directories`` is not set. In this case Patroni is supposed to use the default value from ``libpq``.
+
+- Fix a few issues with Patroni REST API (Alexander)
+
+  The ``clusters_unlocked`` sometimes could be not defined, what resulted in exceptions in the ``GET /metrics`` endpoint. In addition to that the error handling method was assuming that the ``connect_address`` tuple always has two elements, while in fact there could be more in case of IPv6.
+
+- Wait for newly promoted node to finish recovery before deciding to rewind (Alexander)
+
+  It could take some time before the actual promote happens and the new timeline is created. Without waiting replicas could come to the conclusion that rewind isn't required.
+
+- Handle missing timelines in a history file when deciding to rewind (Alexander)
+
+  If the current replica timeline is missing in the history file on the primary the replica was falsely assuming that rewind isn't required.
+
+
+Version 2.1.1
+-------------
+
+**New features**
+
+- Support for ETCD SRV name suffix (David Pavlicek)
+
+  Etcd allows to differentiate between multiple Etcd clusters under the same domain and from now on Patroni also supports it.
+
+- Enrich history with the new leader (huiyalin525)
+
+  It adds the new column to the ``patronictl history`` output.
+
+- Make the CA bundle configurable for in-cluster Kubernetes config (Aron Parsons)
+
+  By default Patroni is using ``/var/run/secrets/kubernetes.io/serviceaccount/ca.crt`` and this new feature allows specifying the custom ``kubernetes.cacert``.
+
+- Support dynamically registering/deregistering as a Consul service and changing tags (Tommy Li)
+
+  Previously it required Patroni restart.
+
+**Bugfixes**
+
+- Avoid unnecessary reload of REST API (Alexander Kukushkin)
+
+  The previous release added a feature of reloading REST API certificates if changed on disk. Unfortunately, the reload was happening unconditionally right after the start.
+
+- Don't resolve cluster members when ``etcd.use_proxies`` is set (Alexander)
+
+  When starting up Patroni checks the healthiness of Etcd cluster by querying the list of members. In addition to that, it also tried to resolve their hostnames, which is not necessary when working with Etcd via proxy and was causing unnecessary warnings.
+
+- Skip rows with NULL values in the ``pg_stat_replication`` (Alexander)
+
+  It seems that the ``pg_stat_replication`` view could contain NULL values in the ``replay_lsn``, ``flush_lsn``, or ``write_lsn`` fields even when ``state = 'streaming'``.
+
+
+Version 2.1.0
+-------------
+
+This version adds compatibility with PostgreSQL v14, makes logical replication slots to survive failover/switchover, implements support of allowlist for REST API, and also reducing the number of logs to one line per heart-beat.
+
+**New features**
+
+- Compatibility with PostgreSQL v14 (Alexander Kukushkin)
+
+  Unpause WAL replay if Patroni is not in a "pause" mode itself. It could be "paused" due to the change of certain parameters like for example ``max_connections`` on the primary.
+
+- Failover logical slots (Alexander)
+
+  Make logical replication slots survive failover/switchover on PostgreSQL v11+. The replication slot if copied from the primary to the replica with restart and later the `pg_replication_slot_advance() <https://www.postgresql.org/docs/11/functions-admin.html#id-1.5.8.31.8.5.2.2.8.1.1>`__ function is used to move it forward. As a result, the slot will already exist before the failover and no events should be lost, but, there is a chance that some events could be delivered more than once.
+
+- Implemented allowlist for Patroni REST API (Alexander)
+
+  If configured, only IP's that matching rules would be allowed to call unsafe endpoints. In addition to that, it is possible to automatically include IP's of members of the cluster to the list.
+
+- Added support of replication connections via unix socket (Mohamad El-Rifai)
+
+  Previously Patroni was always using TCP for replication connection what could cause some issues with SSL verification. Using unix sockets allows exempt replication user from SSL verification.
+
+- Health check on user-defined tags (Arman Jafari Tehrani)
+
+  Along with :ref:`predefined tags: <tags_settings>` it is possible to specify any number of custom tags that become visible in the ``patronictl list`` output and in the REST API. From now on it is possible to use custom tags in health checks.
+
+- Added Prometheus ``/metrics`` endpoint (Mark Mercado, Michael Banck)
+
+  The endpoint exposing the same metrics as ``/patroni``.
+
+- Reduced chattiness of Patroni logs (Alexander)
+
+  When everything goes normal, only one line will be written for every run of HA loop.
+
+
+**Breaking changes**
+
+- The old ``permanent logical replication slots`` feature will no longer work with PostgreSQL v10 and older (Alexander)
+
+  The strategy of creating the logical slots after performing a promotion can't guaranty that no logical events are lost and therefore disabled.
+
+- The ``/leader`` endpoint always returns 200 if the node holds the lock (Alexander)
+
+  Promoting the standby cluster requires updating load-balancer health checks, which is not very convenient and easy to forget. To solve it, we change the behavior of the ``/leader`` health check endpoint. It will return 200 without taking into account whether the cluster is normal or the ``standby_cluster``.
+
+
+**Improvements in Raft support**
+
+- Reliable support of Raft traffic encryption (Alexander)
+
+  Due to the different issues in the ``PySyncObj`` the encryption support was very unstable
+
+- Handle DNS issues in Raft implementation (Alexander)
+
+  If ``self_addr`` and/or ``partner_addrs`` are configured using the DNS name instead of IP's the ``PySyncObj`` was effectively doing resolve only once when the object is created. It was causing problems when the same node was coming back online with a different IP.
+
+
+**Stability improvements**
+
+- Compatibility with ``psycopg2-2.9+`` (Alexander)
+
+  In ``psycopg2`` the ``autocommit = True`` is ignored in the ``with connection`` block, which breaks replication protocol connections.
+
+- Fix excessive HA loop runs with Zookeeper (Alexander)
+
+  Update of member ZNodes was causing a chain reaction and resulted in running the HA loops multiple times in a row.
+
+- Reload if REST API certificate is changed on disk (Michael Todorovic)
+
+  If the REST API certificate file was updated in place Patroni didn't perform a reload.
+
+- Don't create pgpass dir if kerberos auth is used (Kostiantyn Nemchenko)
+
+  Kerberos and password authentication are mutually exclusive.
+
+- Fixed little issues with custom bootstrap (Alexander)
+
+  Start Postgres with ``hot_standby=off`` only when we do a PITR and restart it after PITR is done.
+
+
+**Bugfixes**
+
+- Compatibility with ``kazoo-2.7+`` (Alexander)
+
+  Since Patroni is handling retries on its own, it is relying on the old behavior of ``kazoo`` that requests to a Zookeeper cluster are immediately discarded when there are no connections available.
+
+- Explicitly request the version of Etcd v3 cluster when it is known that we are connecting via proxy (Alexander)
+
+  Patroni is working with Etcd v3 cluster via gPRC-gateway and it depending on the cluster version different endpoints (``/v3``, ``/v3beta``, or ``/v3alpha``) must be used. The version was resolved only together with the cluster topology, but since the latter was never done when connecting via proxy.
+
+
+Version 2.0.2
+-------------
+
+**New features**
+
+- Ability to ignore externally managed replication slots (James Coleman)
+
+  Patroni is trying to remove any replication slot which is unknown to it, but there are certainly cases when replication slots should be managed externally. From now on it is possible to configure slots that should not be removed.
+
+- Added support for cipher suite limitation for REST API (Gunnar "Nick" Bluth)
+
+  It could be configured via ``restapi.ciphers`` or the ``PATRONI_RESTAPI_CIPHERS`` environment variable.
+
+- Added support for encrypted TLS keys for REST API (Jonathan S. Katz)
+
+  It could be configured via ``restapi.keyfile_password`` or the ``PATRONI_RESTAPI_KEYFILE_PASSWORD`` environment variable.
+
+- Constant time comparison of REST API authentication credentials (Alex Brasetvik)
+
+  Use ``hmac.compare_digest()`` instead of ``==``, which is vulnerable to timing attack.
+
+- Choose synchronous nodes based on replication lag (Krishna Sarabu)
+
+  If the replication lag on the synchronous node starts exceeding the configured threshold it could be demoted to asynchronous and/or replaced by the other node. Behaviour is controlled with ``maximum_lag_on_syncnode``.
+
+
+**Stability improvements**
+
+- Start postgres with ``hot_standby = off`` when doing custom bootstrap (Igor Yanchenko)
+
+  During custom bootstrap Patroni is restoring the basebackup, starting Postgres up, and waiting until recovery finishes. Some PostgreSQL parameters on the standby can't be smaller than on the primary and if the new value (restored from WAL) is higher than the configured one, Postgres panics and stops. In order to avoid such behavior we will do custom bootstrap without ``hot_standby`` mode.
+
+- Warn the user if the required watchdog is not healthy (Nicolas Thauvin)
+
+  When the watchdog device is not writable or missing in required mode, the member cannot be promoted. Added a warning to show the user where to search for this misconfiguration.
+
+- Better verbosity for single-user mode recovery (Alexander Kukushkin)
+
+  If Patroni notices that PostgreSQL wasn't shutdown clearly, in certain cases the crash-recovery is executed by starting Postgres in single-user mode. It could happen that the recovery failed (for example due to the lack of space on disk) but errors were swallowed.
+
+- Added compatibility with ``python-consul2`` module (Alexander, Wilfried Roset)
+
+  The good old ``python-consul`` is not maintained since a few years, therefore someone created a fork with new features and bug-fixes.
+
+- Don't use ``bypass_api_service`` when running ``patronictl`` (Alexander)
+
+  When a K8s pod is running in a non-``default`` namespace it does not necessarily have enough permissions to query the ``kubernetes`` endpoint. In this case Patroni shows the warning and ignores the ``bypass_api_service`` setting. In case of ``patronictl`` the warning was a bit annoying.
+
+- Create ``raft.data_dir`` if it doesn't exists or make sure that it is writable (Mark Mercado)
+
+  Improves user-friendliness and usability.
+
+
+**Bugfixes**
+
+- Don't interrupt restart or promote if lost leader lock in pause (Alexander)
+
+  In pause it is allowed to run postgres as primary without lock.
+
+- Fixed issue with ``shutdown_request()`` in the REST API (Nicolas Limage)
+
+  In order to improve handling of SSL connections and delay the handshake until thread is started Patroni overrides a few methods in the ``HTTPServer``. The ``shutdown_request()`` method was forgotten.
+
+- Fixed issue with sleep time when using Zookeeper (Alexander)
+
+  There were chances that Patroni was sleeping up to twice longer between running HA code.
+
+- Fixed invalid ``os.symlink()`` calls when moving data directory after failed bootstrap (Andrew L'Ecuyer)
+
+  If the bootstrap failed Patroni is renaming data directory, pg_wal, and all tablespaces. After that it updates symlinks so filesystem remains consistent. The symlink creation was failing due to the ``src`` and ``dst`` arguments being swapped.
+
+- Fixed bug in the post_bootstrap() method (Alexander)
+
+  If the superuser password wasn't configured Patroni was failing to call the ``post_init`` script and therefore the whole bootstrap was failing.
+
+- Fixed an issues with pg_rewind in the standby cluster (Alexander)
+
+  If the superuser name is different from Postgres, the ``pg_rewind`` in the standby cluster was failing because the connection string didn't contain the database name.
+
+- Exit only if authentication with Etcd v3 explicitly failed (Alexander)
+
+  On start Patroni performs discovery of Etcd cluster topology and authenticates if it is necessarily. It could happen that one of etcd servers is not accessible, Patroni was trying to perform authentication on this server and failing instead of retrying with the next node.
+
+- Handle case with psutil cmdline() returning empty list (Alexander)
+
+  Zombie processes are still postmasters children, but they don't have cmdline()
+
+- Treat ``PATRONI_KUBERNETES_USE_ENDPOINTS`` environment variable as boolean (Alexander)
+
+  Not doing so was making impossible disabling ``kubernetes.use_endpoints`` via environment.
+
+- Improve handling of concurrent endpoint update errors (Alexander)
+
+  Patroni will explicitly query the current endpoint object, verify that the current pod still holds the leader lock and repeat the update.
+
+
+Version 2.0.1
+-------------
+
+**New features**
+
+- Use ``more`` as pager in ``patronictl edit-config`` if ``less`` is not available (Pavel Golub)
+
+  On Windows it would be the ``more.com``. In addition to that, ``cdiff`` was changed to ``ydiff`` in ``requirements.txt``, but ``patronictl`` still supports both for compatibility.
+
+- Added support of ``raft`` ``bind_addr`` and ``password`` (Alexander Kukushkin)
+
+  ``raft.bind_addr`` might be useful when running behind NAT. ``raft.password`` enables traffic encryption (requires the ``cryptography`` module).
+
+- Added ``sslpassword`` connection parameter support (Kostiantyn Nemchenko)
+
+  The connection parameter was introduced in PostgreSQL 13.
+
+**Stability improvements**
+
+- Changed the behavior in pause (Alexander)
+
+  1. Patroni will not call the ``bootstrap`` method if the ``PGDATA`` directory is missing/empty.
+  2. Patroni will not exit on sysid mismatch in pause, only log a warning.
+  3. The node will not try to grab the leader key in pause mode if Postgres is running not in recovery (accepting writes) but the sysid doesn't match with the initialize key.
+
+- Apply ``master_start_timeout`` when executing crash recovery (Alexander)
+
+  If Postgres crashed on the leader node, Patroni does a crash-recovery by starting Postgres in single-user mode. During the crash-recovery the leader lock is being updated. If the crash-recovery didn't finish in ``master_start_timeout`` seconds, Patroni will stop it forcefully and release the leader lock.
+
+- Removed the ``secure`` extra from the ``urllib3`` requirements (Alexander)
+
+  The only reason for adding it there was the ``ipaddress`` dependency for python 2.7.
+
+**Bugfixes**
+
+- Fixed a bug in the ``Kubernetes.update_leader()`` (Alexander)
+
+  An unhandled exception was preventing demoting the primary when the update of the leader object failed.
+
+- Fixed hanging ``patronictl`` when RAFT is being used (Alexander)
+
+  When using ``patronictl`` with Patroni config, ``self_addr`` should be added to the ``partner_addrs``.
+
+- Fixed bug in ``get_guc_value()`` (Alexander)
+
+  Patroni was failing to get the value of ``restore_command`` on PostgreSQL 12, therefore fetching missing WALs for ``pg_rewind`` didn't work.
+
+
+Version 2.0.0
+-------------
+
+This version enhances compatibility with PostgreSQL 13, adds support of multiple synchronous standbys, has significant improvements in handling of ``pg_rewind``, adds support of Etcd v3 and Patroni on pure RAFT (without Etcd, Consul, or Zookeeper), and makes it possible to optionally call the ``pre_promote`` (fencing) script.
+
+**PostgreSQL 13 support**
+
+- Don't fire ``on_reload`` when promoting to ``standby_leader`` on PostgreSQL 13+ (Alexander Kukushkin)
+
+  When promoting to ``standby_leader`` we change ``primary_conninfo``, update the role and reload Postgres. Since ``on_role_change`` and ``on_reload`` effectively duplicate each other, Patroni will call only ``on_role_change``.
+
+- Added support for ``gssencmode`` and ``channel_binding`` connection parameters (Alexander)
+
+  PostgreSQL 12 introduced ``gssencmode`` and 13 ``channel_binding`` connection parameters and now they can be used if defined in the ``postgresql.authentication`` section.
+
+- Handle renaming of ``wal_keep_segments`` to ``wal_keep_size`` (Alexander)
+
+  In case of misconfiguration (``wal_keep_segments`` on 13 and ``wal_keep_size`` on older versions) Patroni will automatically adjust the configuration.
+
+- Use ``pg_rewind`` with ``--restore-target-wal`` on 13 if possible (Alexander)
+
+  On PostgreSQL 13 Patroni checks if ``restore_command`` is configured and tells ``pg_rewind`` to use it.
+
+
+**New features**
+
+- [BETA] Implemented support of Patroni on pure RAFT (Alexander)
+
+  This makes it possible to run Patroni without 3rd party dependencies, like Etcd, Consul, or Zookeeper. For HA you will have to run either three Patroni nodes or two nodes with Patroni and one node with ``patroni_raft_controller``. For more information please check the :ref:`documentation <raft_settings>`.
+
+- [BETA] Implemented support for Etcd v3 protocol via gPRC-gateway (Alexander)
+
+  Etcd 3.0 was released more than four years ago and Etcd 3.4 has v2 disabled by default. There are also chances that v2 will be completely removed from Etcd, therefore we implemented support of Etcd v3 in Patroni. In order to start using it you have to explicitly create the ``etcd3`` section is the Patroni configuration file.
+
+- Supporting multiple synchronous standbys (Krishna Sarabu)
+
+  It allows running a cluster with more than one synchronous replicas. The maximum number of synchronous replicas is controlled by the new parameter ``synchronous_node_count``. It is set to 1 by default and has no effect when the ``synchronous_mode`` is set to ``off``.
+
+- Added possibility to call the ``pre_promote`` script (Sergey Dudoladov)
+
+  Unlike callbacks, the ``pre_promote`` script is called synchronously after acquiring the leader lock, but before promoting Postgres. If the script fails or exits with a non-zero exitcode, the current node will release the leader lock.
+
+- Added support for configuration directories (Floris van Nee)
+
+  YAML files in the directory loaded and applied in alphabetical order.
+
+- Advanced validation of PostgreSQL parameters (Alexander)
+
+  In case the specific parameter is not supported by the current PostgreSQL version or when its value is incorrect, Patroni will remove the parameter completely or try to fix the value.
+
+- Wake up the main thread when the forced checkpoint after promote completed (Alexander)
+
+  Replicas are waiting for checkpoint indication via member key of the leader in DCS. The key is normally updated only once per HA loop. Without waking the main thread up, replicas will have to wait up to ``loop_wait`` seconds longer than necessary.
+
+- Use of ``pg_stat_wal_recevier`` view on 9.6+ (Alexander)
+
+  The view contains up-to-date values of ``primary_conninfo`` and ``primary_slot_name``, while the contents of ``recovery.conf`` could be stale.
+
+- Improved handing of IPv6 addresses in the Patroni config file (Mateusz Kowalski)
+
+  The IPv6 address is supposed to be enclosed into square brackets, but Patroni was expecting to get it plain. Now both formats are supported.
+
+- Added Consul ``service_tags`` configuration parameter (Robert Edström)
+
+  They are useful for dynamic service discovery, for example by load balancers.
+
+- Implemented SSL support for Zookeeper (Kostiantyn Nemchenko)
+
+  It requires ``kazoo>=2.6.0``.
+
+- Implemented ``no_params`` option for custom bootstrap method (Kostiantyn)
+
+  It allows calling ``wal-g``, ``pgBackRest`` and other backup tools without wrapping them into shell scripts.
+
+- Move WAL and tablespaces after a failed init (Feike Steenbergen)
+
+  When doing ``reinit``, Patroni was already removing not only ``PGDATA`` but also the symlinked WAL directory and tablespaces. Now the ``move_data_directory()`` method will do a similar job, i.e. rename WAL directory and tablespaces and update symlinks in PGDATA.
+
+
+**Improved in pg_rewind support**
+
+- Improved timeline divergence check (Alexander)
+
+  We don't need to rewind when the replayed location on the replica is not ahead of the switchpoint or the end of the checkpoint record on the former primary is the same as the switchpoint. In order to get the end of the checkpoint record we use ``pg_waldump`` and parse its output.
+
+- Try to fetch missing WAL if ``pg_rewind`` complains about it (Alexander)
+
+  It could happen that the WAL segment required for ``pg_rewind`` doesn't exist in the ``pg_wal`` directory anymore and therefore ``pg_rewind`` can't find the checkpoint location before the divergence point. Starting from PostgreSQL 13 ``pg_rewind`` could use ``restore_command`` for fetching missing WALs. For older PostgreSQL versions Patroni parses the errors of a failed rewind attempt and tries to fetch the missing WAL by calling the ``restore_command`` on its own.
+
+- Detect a new timeline in the standby cluster and trigger rewind/reinitialize if necessary (Alexander)
+
+  The ``standby_cluster`` is decoupled from the primary cluster and therefore doesn't immediately know about leader elections and timeline switches. In order to detect the fact, the ``standby_leader`` periodically checks for new history files in ``pg_wal``.
+
+- Shorten and beautify history log output (Alexander)
+
+  When Patroni is trying to figure out the necessity of ``pg_rewind``, it could write the content of the history file from the primary into the log. The history file is growing with every failover/switchover and eventually starts taking up too many lines, most of which are not so useful. Instead of showing the raw data, Patroni will show only 3 lines before the current replica timeline and 2 lines after.
+
+
+**Improvements on K8s**
+
+- Get rid of ``kubernetes`` python module (Alexander)
+
+  The official python kubernetes client contains a lot of auto-generated code and therefore very heavy. Patroni uses only a small fraction of K8s API endpoints and implementing support for them wasn't hard.
+
+- Make it possible to bypass the ``kubernetes`` service (Alexander)
+
+  When running on K8s, Patroni is usually communicating with the K8s API via the ``kubernetes`` service, the address of which is exposed in the ``KUBERNETES_SERVICE_HOST`` environment variable. Like any other service, the ``kubernetes`` service is handled by ``kube-proxy``, which in turn, depending on the configuration, is either relying on a userspace program or ``iptables`` for traffic routing. Skipping the intermediate component and connecting directly to the K8s master nodes allows us to implement a better retry strategy and mitigate risks of demoting Postgres when K8s master nodes are upgraded.
+
+- Sync HA loops of all pods of a Patroni cluster (Alexander)
+
+  Not doing so was increasing failure detection time from ``ttl`` to ``ttl + loop_wait``.
+
+- Populate ``references`` and ``nodename`` in the subsets addresses on K8s (Alexander)
+
+  Some load-balancers are relying on this information.
+
+- Fix possible race conditions in the ``update_leader()`` (Alexander)
+
+  The concurrent update of the leader configmap or endpoint happening outside of Patroni might cause the ``update_leader()`` call to fail. In this case Patroni rechecks that the current node is still owning the leader lock and repeats the update.
+
+- Explicitly disallow patching non-existent config (Alexander)
+
+  For DCS other than ``kubernetes`` the PATCH call is failing with an exception due to ``cluster.config`` being ``None``, but on Kubernetes it was happily creating the config annotation and preventing writing bootstrap configuration after the bootstrap finished.
+
+- Fix bug in ``pause`` (Alexander)
+
+  Replicas were removing ``primary_conninfo`` and restarting Postgres when the leader key was absent, but they should do nothing.
+
+
+**Improvements in REST API**
+
+- Defer TLS handshake until worker thread has started (Alexander, Ben Harris)
+
+  If the TLS handshake was done in the API thread and the client-side didn't send any data, the API thread was blocked (risking DoS).
+
+- Check ``basic-auth`` independently from client certificate in REST API (Alexander)
+
+  Previously only the client certificate was validated. Doing two checks independently is an absolutely valid use-case.
+
+- Write double ``CRLF`` after HTTP headers of the ``OPTIONS`` request (Sergey Burladyan)
+
+  HAProxy was happy with a single ``CRLF``, while Consul health-check complained about broken connection and unexpected EOF.
+
+- ``GET /cluster`` was showing stale members info for Zookeeper (Alexander)
+
+  The endpoint was using the Patroni internal cluster view. For Patroni itself it didn't cause any issues, but when exposed to the outside world we need to show up-to-date information, especially replication lag.
+
+- Fixed health-checks for standby cluster (Alexander)
+
+  The ``GET /standby-leader`` for a master and ``GET /master`` for a ``standby_leader`` were incorrectly responding with 200.
+
+- Implemented ``DELETE /switchover`` (Alexander)
+
+  The REST API call deletes the scheduled switchover.
+
+- Created ``/readiness`` and ``/liveness`` endpoints (Alexander)
+
+  They could be useful to eliminate "unhealthy" pods from subsets addresses when the K8s service is used with label selectors.
+
+- Enhanced ``GET /replica`` and ``GET /async`` REST API health-checks (Krishna, Alexander)
+
+  Checks now support optional keyword ``?lag=<max-lag>`` and will respond with 200 only if the lag is smaller than the supplied value. If relying on this feature please keep in mind that information about WAL position on the leader is updated only every ``loop_wait`` seconds!
+
+- Added support for user defined HTTP headers in the REST API response (Yogesh Sharma)
+
+  This feature might be useful if requests are made from a browser.
+
+
+**Improvements in patronictl**
+
+- Don't try to call non-existing leader in ``patronictl pause`` (Alexander)
+
+  While pausing a cluster without a leader on K8s, ``patronictl`` was showing warnings that member "None" could not be accessed.
+
+- Handle the case when member ``conn_url`` is missing (Alexander)
+
+  On K8s it is possible that the pod doesn't have the necessary annotations because Patroni is not yet running. It was making ``patronictl`` to fail.
+
+- Added ability to print ASCII cluster topology (Maxim Fedotov, Alexander)
+
+  It is very useful to get overview of the cluster with cascading replication.
+
+- Implement ``patronictl flush switchover`` (Alexander)
+
+  Before that ``patronictl flush`` only supported cancelling scheduled restarts.
+
+
+**Bugfixes**
+
+- Attribute error during bootstrap of the cluster with existing PGDATA (Krishna)
+
+  When trying to create/update the ``/history`` key, Patroni was accessing the ``ClusterConfig`` object which wasn't created in DCS yet.
+
+- Improved exception handling in Consul (Alexander)
+
+  Unhandled exception in the ``touch_member()`` method caused the whole Patroni process to crash.
+
+- Enforce ``synchronous_commit=local`` for the ``post_init`` script (Alexander)
+
+  Patroni was already doing that when creating users (``replication``, ``rewind``), but missing it in the case of ``post_init`` was an oversight. As a result, if the script wasn't doing it internally on it's own the bootstrap in ``synchronous_mode`` wasn't able to finish.
+
+- Increased ``maxsize`` in the Consul pool manager (ponvenkates)
+
+  With the default ``size=1`` some warnings were generated.
+
+- Patroni was wrongly reporting Postgres as running (Alexander)
+
+  The state wasn't updated when for example Postgres crashed due to an out-of-disk error.
+
+- Put ``*`` into ``pgpass`` instead of missing or empty values (Alexander)
+
+  If for example the ``standby_cluster.port`` is not specified, the ``pgpass`` file was incorrectly generated.
+
+- Skip physical replication slot creation on the leader node with special characters (Krishna)
+
+  Patroni appeared to be creating a dormant slot (when ``slots`` defined) for the leader node when the name contained special chars such as '-'  (for e.g. "abc-us-1").
+
+- Avoid removing non-existent ``pg_hba.conf`` in the custom bootstrap (Krishna)
+
+  Patroni was failing if ``pg_hba.conf`` happened to be located outside of the ``pgdata`` dir after custom bootstrap.
+
+
 Version 1.6.5
 -------------
 
@@ -316,7 +914,7 @@ Version 1.6.1
 
 - Some improvements in logging infrastructure (Alexander Kukushkin)
 
-  Previously threre was a possibility to loose the last few log lines on shutdown because the logging thread was a ``daemon`` thread.
+  Previously there was a possibility to loose the last few log lines on shutdown because the logging thread was a ``daemon`` thread.
 
 - Use ``spawn`` multiprocessing start method on python 3.4+ (Maciej Kowalczyk)
 
@@ -366,7 +964,7 @@ Version 1.6.1
 
   If the method is executed from the REST API thread, it requires a separate cursor object to be created.
 
-- Fix the problem of not promoting the sync standby that had a name contaning upper case letters (Alexander Kukushkin)
+- Fix the problem of not promoting the sync standby that had a name containing upper case letters (Alexander Kukushkin)
 
   We converted the name to the lower case because Postgres was doing the same while comparing the ``application_name`` with the value in ``synchronous_standby_names``.
 
@@ -642,7 +1240,7 @@ Compatibility and bugfix release.
 
 - Fix broken compatibility with postgres 9.3 (Alexander)
 
-  When opening a replication connection we should specify replication=1, beacuse 9.3 does not understand replication='database'
+  When opening a replication connection we should specify replication=1, because 9.3 does not understand replication='database'
 
 - Make sure we refresh Consul session at least once per HA loop and improve handling of consul sessions exceptions (Alexander)
 
@@ -727,7 +1325,7 @@ This version enables Patroni HA cluster to operate in a standby mode, introduces
 
 - Immediately reserve the WAL position upon creation of the replication slot (Alexander Kukushkin)
 
-  Starting from 9.6, `pg_create_physical_replication_slot` function provides an additional boolean parameter `immediately_reserve`. When it is set to `false`, which is also the default, the slot doesn't reserve the WAL position until it receives the first client connection, potentially losing some segments required by the client in a time window between the slot creation and the intiial client connection.
+  Starting from 9.6, `pg_create_physical_replication_slot` function provides an additional boolean parameter `immediately_reserve`. When it is set to `false`, which is also the default, the slot doesn't reserve the WAL position until it receives the first client connection, potentially losing some segments required by the client in a time window between the slot creation and the initial client connection.
 
 - Fix bug in strict synchronous replication (Alexander Kukushkin)
 
@@ -967,7 +1565,7 @@ This version adds support for using Kubernetes as a DCS, allowing to run Patroni
 
 **Upgrade notice**
 
-Installing Patroni via pip will no longer bring in dependencies for (such as libraries for Etcd, Zookeper, Consul or Kubernetes, or support for AWS). In order to enable them one need to list them in pip install command explicitely, for instance `pip install patroni[etcd,kubernetes]`.
+Installing Patroni via pip will no longer bring in dependencies for (such as libraries for Etcd, Zookeper, Consul or Kubernetes, or support for AWS). In order to enable them one need to list them in pip install command explicitly, for instance `pip install patroni[etcd,kubernetes]`.
 
 **Kubernetes support**
 
@@ -986,7 +1584,7 @@ In addition to using Endpoints, Patroni supports ConfigMaps. You can find more i
 
 - Remove leader key on shutdown only when we have the lock (Ants)
 
-  Unconditional removal was generating unnecessary and missleading exceptions.
+  Unconditional removal was generating unnecessary and misleading exceptions.
 
 **Improvements in patronictl**
 
@@ -1017,7 +1615,7 @@ In addition to using Endpoints, Patroni supports ConfigMaps. You can find more i
 
 - Alter the behavior of ``patronictl failover`` (Alexander)
 
-  It will work even if there is no leader, but in that case you will have to explicitely specify a node which should become the new leader.
+  It will work even if there is no leader, but in that case you will have to explicitly specify a node which should become the new leader.
 
 **Expose information about timeline and history**
 
@@ -1033,7 +1631,7 @@ In addition to using Endpoints, Patroni supports ConfigMaps. You can find more i
 
 - Add new /sync and /async endpoints (Alexander, Oleksii Kliukin)
 
- Those endpoints (also accessible as /synchronous and /asynchronous) return 200 only for synchronous and asynchornous replicas correspondingly (exclusing those marked as `noloadbalance`).
+ Those endpoints (also accessible as /synchronous and /asynchronous) return 200 only for synchronous and asynchronous replicas correspondingly (exclusing those marked as `noloadbalance`).
 
 **Allow multiple hosts for Etcd**
 
@@ -1121,7 +1719,7 @@ Version 1.3.4
 
 - Pass the consul token as a header (Andrew Colin Kissa)
 
-  Headers are now the prefered way to pass the token to the consul `API <https://www.consul.io/api/index.html#authentication>`__.
+  Headers are now the preferred way to pass the token to the consul `API <https://www.consul.io/api/index.html#authentication>`__.
 
 
 - Advanced configuration for Consul (Alexander Kukushkin)
@@ -1439,7 +2037,7 @@ In addition, patronictl supports new ``pause`` and ``resume`` commands to toggle
   Originally, ping_timeout and connect_timeout values were calculated from the negotiated session timeout. Patroni loop_wait was not taken into account. As
   a result, a single retry could take more time than the session timeout, forcing Patroni to release the lock and demote.
 
-  This change set ping and connect timeout to half of the value of loop_wait, speeding up detection of connection issues and  leaving enough time to retry the connection attempt before loosing the lock.
+  This change set ping and connect timeout to half of the value of loop_wait, speeding up detection of connection issues and  leaving enough time to retry the connection attempt before losing the lock.
 
 - Update Etcd topology only after original request succeed (Alexander)
 
@@ -1517,7 +2115,7 @@ When upgrading from v0.90 or below, always upgrade all replicas before the maste
 
   See the :ref:`dynamic configuration <dynamic_configuration>`  for the details on which parameters can be changed and the order of processing difference configuration sources.
 
-  The configuration file format *has changed* since the v0.90. Patroni is still compatible with the old configuration files, but in order to take advantage of the bootstrap parameters one needs to change it. Users are encourage to update them by referring to the :ref:`dynamic configuraton documentation page <dynamic_configuration>`.
+  The configuration file format *has changed* since the v0.90. Patroni is still compatible with the old configuration files, but in order to take advantage of the bootstrap parameters one needs to change it. Users are encourage to update them by referring to the :ref:`dynamic configuration documentation page <dynamic_configuration>`.
 
 **More flexible configuration***
 

docs/replica_bootstrap.rst

@@ -24,6 +24,7 @@ arguments to them, i.e. the name of the cluster and the path to the data directo
         <custom_bootstrap_method_name>:
             command: <path_to_custom_bootstrap_script> [param1 [, ...]]
             keep_existing_recovery_conf: False
+            no_params: False
             recovery_conf:
                 recovery_target_action: promote
                 recovery_target_timeline: latest
@@ -40,6 +41,8 @@ in the configuration files, Patroni supplies two cluster-specific ones:
 --datadir
     Path to the data directory of the cluster instance to be bootstrapped
 
+Passing these two additional flags can be disabled by setting a special ``no_params`` parameter to ``True``.
+
 If the bootstrap script returns 0, Patroni tries to configure and start the PostgreSQL instance produced by it. If any
 of the intermediate steps fail, or the script returns a non-zero value, Patroni assumes that the bootstrap has failed,
 cleans up after itself and releases the initialize lock to give another node the opportunity to bootstrap.
@@ -140,6 +143,10 @@ possible to specify a ``basebackup`` configuration section. Same rules as with t
 namely, only long (with --) options should be specified there. Not all parameters make sense, if you override a connection
 string or provide an option to created tar-ed or compressed base backups, patroni won't be able to make a replica out
 of it. There is no validation performed on the names or values of the parameters passed to the ``basebackup`` section.
+Also note that in case symlinks are used for the WAL folder it is up to the user to specify the correct ``--waldir``
+path as an option, so that after replica buildup or re-initialization the symlink would persist. This option is supported
+only since v10 though.
+
 You can specify basebackup parameters as either a map (key-value pairs) or a list of elements, where each element
 could be either a key-value pair or a single key (for options that does not receive any values, for instance, ``--verbose``).
 Consider those 2 examples:
@@ -159,6 +166,7 @@ and
         basebackup:
             - verbose
             - max-rate: '100M'
+            - waldir: /pg-wal-mount/external-waldir
 
 If all replica creation methods fail, Patroni will try again all methods in order during the next event loop cycle.
 

docs/replication_modes.rst

@@ -59,11 +59,14 @@ Synchronous mode can be switched on and off via Patroni REST interface. See :ref
 
 Note: Because of the way synchronous replication is implemented in PostgreSQL it is still possible to lose transactions even when using ``synchronous_mode_strict``. If the PostgreSQL backend is cancelled while waiting to acknowledge replication (as a result of packet cancellation due to client timeout or backend failure) transaction changes become visible for other backends. Such changes are not yet replicated and may be lost in case of standby promotion.
 
+Synchronous Replication Factor
+------------------------------
+The parameter ``synchronous_node_count`` is used by Patroni to manage number of synchronous standby databases. It is set to 1 by default. It has no effect when ``synchronous_mode`` is set to off. When enabled, Patroni manages precise number of synchronous standby databases based on parameter ``synchronous_node_count`` and adjusts the state in DCS & synchronous_standby_names as members join and leave.
 
 Synchronous mode implementation
 -------------------------------
 
-When in synchronous mode Patroni maintains synchronization state in the DCS, containing the latest primary and current synchronous standby. This state is updated with strict ordering constraints to ensure the following invariants:
+When in synchronous mode Patroni maintains synchronization state in the DCS, containing the latest primary and current synchronous standby databases. This state is updated with strict ordering constraints to ensure the following invariants:
 
 - A node must be marked as the latest leader whenever it can accept write transactions. Patroni crashing or PostgreSQL not shutting down can cause violations of this invariant.
 
@@ -71,9 +74,9 @@ When in synchronous mode Patroni maintains synchronization state in the DCS, con
 
 - A node that is not the leader or current synchronous standby is not allowed to promote itself automatically.
 
-Patroni will only ever assign one standby to ``synchronous_standby_names`` because with multiple candidates it is not possible to know which node was acting as synchronous during the failure.
+Patroni will only assign one or more synchronous standby nodes based on ``synchronous_node_count`` parameter to ``synchronous_standby_names``.
 
-On each HA loop iteration Patroni re-evaluates synchronous standby choice. If the current synchronous standby is connected and has not requested its synchronous status to be removed it remains picked. Otherwise the cluster member available for sync that is furthest ahead in replication is picked.
+On each HA loop iteration Patroni re-evaluates synchronous standby nodes choice. If the current list of synchronous standby nodes are connected and has not requested its synchronous status to be removed it remains picked. Otherwise the cluster member available for sync that is furthest ahead in replication is picked.
 
 
 .. [1] The data is still there, but recovering it requires a manual recovery effort by data recovery specialists. When Patroni is allowed to rewind with ``use_pg_rewind`` the forked timeline will be automatically erased to rejoin the failed primary with the cluster.

docs/rest_api.rst

@@ -9,26 +9,82 @@ Health check endpoints
 ----------------------
 For all health check ``GET`` requests Patroni returns a JSON document with the status of the node, along with the HTTP status code. If you don't want or don't need the JSON document, you might consider using the ``OPTIONS`` method instead of ``GET``.
 
-- The following requests to Patroni REST API will return HTTP status code **200** only when the Patroni node is running as the leader:
+- The following requests to Patroni REST API will return HTTP status code **200** only when the Patroni node is running as the primary with leader lock:
 
   - ``GET /``
   - ``GET /master``
-  - ``GET /leader``
   - ``GET /primary``
   - ``GET /read-write``
 
+- ``GET /standby-leader``: returns HTTP status code **200** only when the Patroni node is running as the leader in a :ref:`standby cluster <standby_cluster>`.
+
+- ``GET /leader``: returns HTTP status code **200** when the Patroni node has the leader lock. The major difference from the two previous endpoints is that it doesn't take into account whether PostgreSQL is running as the ``primary`` or the ``standby_leader``.
+
 - ``GET /replica``: replica health check endpoint. It returns HTTP status code **200** only when the Patroni node is in the state ``running``, the role is ``replica`` and ``noloadbalance`` tag is not set.
 
-- ``GET /read-only``: like the above endpoint, but also includes the primary.
+- ``GET /replica?lag=<max-lag>``: replica check endpoint. In addition to checks from ``replica``, it also checks replication latency and returns status code **200** only when it is below specified value. The key cluster.last_leader_operation from DCS is used for Leader wal position and compute latency on replica for performance reasons. max-lag can be specified in bytes (integer) or in human readable values, for e.g. 16kB, 64MB, 1GB.
 
-- ``GET /standby-leader``: returns HTTP status code **200** only when the Patroni node is running as the leader in a :ref:`standby cluster <standby_cluster>`.
+  - ``GET /replica?lag=1048576``
+  - ``GET /replica?lag=1024kB``
+  - ``GET /replica?lag=10MB``
+  - ``GET /replica?lag=1GB``
+
+- ``GET /replica?tag_key1=value1&tag_key2=value2``: replica check endpoint. In addition, It will also check for user defined tags ``key1`` and ``key2`` and their respective values in the **tags** section of the yaml configuration management. If the tag isn't defined for an instance, or if the value in the yaml configuration doesn't match the querying value, it will return HTTP Status Code 503.
+
+ In the following requests, since we are checking for the leader or standby-leader status, Patroni doesn't apply any of the user defined tags and they will be ignored.
+  - ``GET /?tag_key1=value1&tag_key2=value2``
+  - ``GET /master?tag_key1=value1&tag_key2=value2``
+  - ``GET /leader?tag_key1=value1&tag_key2=value2``
+  - ``GET /primary?tag_key1=value1&tag_key2=value2``
+  - ``GET /read-write?tag_key1=value1&tag_key2=value2``
+  - ``GET /standby_leader?tag_key1=value1&tag_key2=value2``
+  - ``GET /standby-leader?tag_key1=value1&tag_key2=value2``
+
+- ``GET /read-only``: like the above endpoint, but also includes the primary.
 
 - ``GET /synchronous`` or ``GET /sync``: returns HTTP status code **200** only when the Patroni node is running as a synchronous standby.
 
 - ``GET /asynchronous`` or ``GET /async``: returns HTTP status code **200** only when the Patroni node is running as an asynchronous standby.
 
+- ``GET /asynchronous?lag=<max-lag>`` or ``GET /async?lag=<max-lag>``: asynchronous standby check endpoint. In addition to checks from ``asynchronous`` or ``async``, it also checks replication latency and returns status code **200** only when it is below specified value. The key cluster.last_leader_operation from DCS is used for Leader wal position and compute latency on replica for performance reasons. max-lag can be specified in bytes (integer) or in human readable values, for e.g. 16kB, 64MB, 1GB.
+
+  - ``GET /async?lag=1048576``
+  - ``GET /async?lag=1024kB``
+  - ``GET /async?lag=10MB``
+  - ``GET /async?lag=1GB``
+
 - ``GET /health``: returns HTTP status code **200** only when PostgreSQL is up and running.
 
+- ``GET /liveness``: always returns HTTP status code **200** what only indicates that Patroni is running. Could be used for ``livenessProbe``.
+
+- ``GET /readiness``: returns HTTP status code **200** when the Patroni node is running as the leader or when PostgreSQL is up and running. The endpoint could be used for ``readinessProbe`` when it is not possible to use Kubernetes endpoints for leader elections (OpenShift).
+
+Both, ``readiness`` and ``liveness`` endpoints are very light-weight and not executing any SQL. Probes should be configured in such a way that they start failing about time when the leader key is expiring. With the default value of ``ttl``, which is ``30s`` example probes would look like:
+
+.. code-block:: yaml
+
+    readinessProbe:
+      httpGet:
+        scheme: HTTP
+        path: /readiness
+        port: 8008
+      initialDelaySeconds: 3
+      periodSeconds: 10
+      timeoutSeconds: 5
+      successThreshold: 1
+      failureThreshold: 3
+    livenessProbe:
+      httpGet:
+        scheme: HTTP
+        path: /liveness
+        port: 8008
+      initialDelaySeconds: 3
+      periodSeconds: 10
+      timeoutSeconds: 5
+      successThreshold: 1
+      failureThreshold: 3
+
+
 Monitoring endpoint
 -------------------
 
@@ -149,7 +205,6 @@ Config endpoint
 	    "parameters": {
 	      "hot_standby": "on",
 	      "wal_log_hints": "on",
-	      "wal_keep_segments": 8,
 	      "wal_level": "hot_standby",
 	      "max_wal_senders": 5,
 	      "max_replication_slots": 5,
@@ -177,7 +232,6 @@ Config endpoint
 	    "parameters": {
 	      "hot_standby": "on",
 	      "wal_log_hints": "on",
-	      "wal_keep_segments": 8,
 	      "wal_level": "hot_standby",
 	      "max_wal_senders": 5,
 	      "max_replication_slots": 5,
@@ -229,7 +283,6 @@ If you want to remove (reset) some setting just patch it with ``null``:
 	    "parameters": {
 	      "hot_standby": "on",
 	      "unix_socket_directories": ".",
-	      "wal_keep_segments": 8,
 	      "wal_level": "hot_standby",
 	      "wal_log_hints": "on",
 	      "max_wal_senders": 5,
@@ -245,7 +298,7 @@ The above call removes ``postgresql.parameters.max_connections`` from the dynami
 .. code-block:: bash
 
 	$ curl -s -XPUT -d \
-		'{"maximum_lag_on_failover":1048576,"retry_timeout":10,"postgresql":{"use_slots":true,"use_pg_rewind":true,"parameters":{"hot_standby":"on","wal_log_hints":"on","wal_keep_segments":8,"wal_level":"hot_standby","unix_socket_directories":".","max_wal_senders":5}},"loop_wait":3,"ttl":20}' \
+		'{"maximum_lag_on_failover":1048576,"retry_timeout":10,"postgresql":{"use_slots":true,"use_pg_rewind":true,"parameters":{"hot_standby":"on","wal_log_hints":"on","wal_level":"hot_standby","unix_socket_directories":".","max_wal_senders":5}},"loop_wait":3,"ttl":20}' \
 		http://localhost:8008/config | jq .
 	{
 	  "ttl": 20,
@@ -256,7 +309,6 @@ The above call removes ``postgresql.parameters.max_connections`` from the dynami
 	    "parameters": {
 	      "hot_standby": "on",
 	      "unix_socket_directories": ".",
-	      "wal_keep_segments": 8,
 	      "wal_level": "hot_standby",
 	      "wal_log_hints": "on",
 	      "max_wal_senders": 5
@@ -299,7 +351,10 @@ Example: schedule a switchover from the leader to any other healthy replica in t
 
 Depending on the situation the request might finish with a different HTTP status code and body. The status code **200** is returned when the switchover or failover successfully completed. If the switchover was successfully scheduled, Patroni will return HTTP status code **202**. In case something went wrong, the error status code (one of **400**, **412** or **503**) will be returned with some details in the response body. For more information please check the source code of ``patroni/api.py:do_POST_failover()`` method.
 
-The switchover and failover endpoints are used by ``patronictl switchover`` and ``patronictl failover``, respectively.
+- ``DELETE /switchover``: delete the scheduled switchover
+
+The ``POST /switchover`` and ``POST failover`` endpoints are used by ``patronictl switchover`` and ``patronictl failover``, respectively.
+The ``DELETE /switchover`` is used by ``patronictl flush <cluster-name> switchover``.
 
 
 Restart endpoint
@@ -315,7 +370,7 @@ Restart endpoint
 
 - ``DELETE /restart``: delete the scheduled restart
 
-``POST /restart`` and ``DELETE /restart`` endpoints are used by ``patronictl restart`` and ``patronictl flush`` respectively.
+``POST /restart`` and ``DELETE /restart`` endpoints are used by ``patronictl restart`` and ``patronictl flush <cluster-name> restart`` respectively.
 
 
 Reload endpoint

docs/security.rst

@@ -0,0 +1,37 @@
+.. _security:
+
+=======================
+Security Considerations
+=======================
+
+A Patroni cluster has two interfaces to be protected from unauthorized access: the distributed configuration storage (DCS) and the Patroni REST API.
+
+Protecting DCS
+==============
+
+Patroni and patronictl both store and retrieve data to/from the DCS. 
+
+Despite DCS doesn't contain any sensitive information, it allows changing some of Patroni/Postgres configuration. Therefore the very first thing that should be protected is DCS itself.
+
+The details of protection depend on the type of DCS used. The authentication and encryption parameters (tokens/basic-auth/client certificates) for the supported types of DCS are covered in :ref:`SETTINGS <bootstrap_settings>` 
+
+The general recommendation is to enable TLS for all DCS communication.
+
+Protecting the REST API
+=======================
+
+Protecting the REST API is a more complicated task.
+
+The Patroni REST API is used by Patroni itself during the leader race, by the ``patronictl`` tool in order to perform failovers/switchovers/reinitialize/restarts/reloads, by HAProxy or any other kind of load balancer to perform HTTP health checks, and of course could also be used for monitoring. 
+
+From the point of view of security, REST API contains safe (``GET`` requests, only retrieve information) and unsafe (``PUT``, ``POST``, ``PATCH`` and ``DELETE`` requests, change the state of nodes) endpoints.
+
+The unsafe endpoints can be protected with HTTP basic-auth by setting the ``restapi.authentication.username`` and ``restapi.authentication.password`` parameters. There is no way to protect the safe endpoints without enabling TLS.
+
+When TLS for the REST API is enabled and a PKI is established, mutual authentication of the API server and API client is possible for all endpoints.
+
+The ``restapi`` section parameters enable TLS client authentication to the server. Depending on the value of the ``verify_client`` parameter, the API server requires a successful client certificate verification for both safe and unsafe API calls (``verify_client: required``), or only for unsafe API calls (``verify_client: optional``), or for no API calls (``verify_client: none``).
+
+The ``ctl`` section parameters enable TLS server authentication to the client (the ``patronictl`` tool which uses the same config as patroni). Set ``insecure: true`` to disable the server certificate verification by the client. See :ref:`SETTINGS <patronictl_settings>` for a detailed description of the TLS client parameters.
+
+Protecting the PostgreSQL database proper from unauthorized access is beyond the scope of this document and is covered in https://www.postgresql.org/docs/current/client-authentication.html

extras/startup-scripts/patroni.service

@@ -14,7 +14,8 @@ Group=postgres
 # Read in configuration file if it exists, otherwise proceed
 EnvironmentFile=-/etc/patroni_env.conf
 
-WorkingDirectory=~
+# the default is the user's home directory, and if you want to change it, you must provide an absolute path.
+# WorkingDirectory=/home/sameuser
 
 # Where to send early-startup messages from the server
 # This is normally controlled by the global default set by systemd

features/basic_replication.feature

@@ -28,6 +28,46 @@ Feature: basic replication
     When I issue a GET request to http://127.0.0.1:8009/async
     Then I receive a response code 200
 
+  Scenario: check stuck sync replica
+    Given I issue a PATCH request to http://127.0.0.1:8008/config with {"pause": true, "maximum_lag_on_syncnode": 15000000, "postgresql": {"parameters": {"synchronous_commit": "remote_apply"}}}
+    Then I receive a response code 200
+    And I create table on postgres0
+    And table mytest is present on postgres1 after 2 seconds
+    And table mytest is present on postgres2 after 2 seconds
+    When I pause wal replay on postgres2
+    And I load data on postgres0
+    Then "sync" key in DCS has sync_standby=postgres1 after 15 seconds
+    And I resume wal replay on postgres2
+    And I sleep for 2 seconds
+    And I issue a GET request to http://127.0.0.1:8009/sync
+    Then I receive a response code 200
+    When I issue a GET request to http://127.0.0.1:8010/async
+    Then I receive a response code 200
+    When I issue a PATCH request to http://127.0.0.1:8008/config with {"pause": null, "maximum_lag_on_syncnode": -1, "postgresql": {"parameters": {"synchronous_commit": "on"}}}
+    Then I receive a response code 200
+    And I drop table on postgres0
+
+  Scenario: check multi sync replication
+    Given I issue a PATCH request to http://127.0.0.1:8008/config with {"synchronous_node_count": 2}
+    Then I receive a response code 200
+    And I sleep for 10 seconds
+    Then "sync" key in DCS has sync_standby=postgres1,postgres2 after 5 seconds
+    When I issue a GET request to http://127.0.0.1:8010/sync
+    Then I receive a response code 200
+    When I issue a GET request to http://127.0.0.1:8009/sync
+    Then I receive a response code 200
+    When I issue a PATCH request to http://127.0.0.1:8008/config with {"synchronous_node_count": 1}
+    Then I receive a response code 200
+    And I shut down postgres1
+    And I sleep for 10 seconds
+    Then "sync" key in DCS has sync_standby=postgres2 after 10 seconds
+    When I start postgres1
+    And "members/postgres1" key in DCS has state=running after 10 seconds
+    When I issue a GET request to http://127.0.0.1:8010/sync
+    Then I receive a response code 200
+    When I issue a GET request to http://127.0.0.1:8009/async
+    Then I receive a response code 200
+
   Scenario: check the basic failover in synchronous mode
     Given I run patronictl.py pause batman
     Then I receive a response returncode 0

features/callback.py

@@ -1,17 +0,0 @@
-#!/usr/bin/env python
-import os
-import psycopg2
-import sys
-
-
-if __name__ == '__main__':
-    if not (len(sys.argv) >= 3 and sys.argv[3] == "master"):
-        sys.exit(1)
-
-    os.environ['PGPASSWORD'] = 'zalando'
-    connection = psycopg2.connect(host='127.0.0.1', port=sys.argv[1], user='postgres')
-    cursor = connection.cursor()
-    cursor.execute("SELECT slot_name FROM pg_replication_slots WHERE slot_type = 'logical'")
-
-    with open("data/postgres0/label", "w") as label:
-        label.write(next(iter(cursor.fetchone()), ""))

features/environment.py

@@ -1,7 +1,6 @@
 import abc
 import datetime
 import os
-import psycopg2
 import json
 import shutil
 import signal
@@ -13,6 +12,10 @@ import threading
 import time
 import yaml
 
+import patroni.psycopg as psycopg
+
+from six.moves.BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
+
 
 @six.add_metaclass(abc.ABCMeta)
 class AbstractController(object):
@@ -165,13 +168,20 @@ class PatroniController(AbstractController):
             config = yaml.safe_load(f)
             config.pop('etcd', None)
 
+        raft_port = os.environ.get('RAFT_PORT')
+        if raft_port:
+            os.environ['RAFT_PORT'] = str(int(raft_port) + 1)
+            config['raft'] = {'data_dir': self._output_dir, 'self_addr': 'localhost:' + os.environ['RAFT_PORT']}
+
         host = config['postgresql']['listen'].split(':')[0]
 
         config['postgresql']['listen'] = config['postgresql']['connect_address'] = '{0}:{1}'.format(host, self.__PORT)
 
         config['name'] = name
         config['postgresql']['data_dir'] = self._data_dir
+        config['postgresql']['basebackup'] = [{'checkpoint': 'fast'}]
         config['postgresql']['use_unix_socket'] = os.name != 'nt'  # windows doesn't yet support unix-domain sockets
+        config['postgresql']['use_unix_socket_repl'] = os.name != 'nt'  # windows doesn't yet support unix-domain sockets
         config['postgresql']['pgpass'] = os.path.join(tempfile.gettempdir(), 'pgpass_' + name)
         config['postgresql']['parameters'].update({
             'logging_collector': 'on', 'log_destination': 'csvlog', 'log_directory': self._output_dir,
@@ -186,6 +196,8 @@ class PatroniController(AbstractController):
         if custom_config is not None:
             self.recursive_update(config, custom_config)
 
+        self.recursive_update(config, {
+            'bootstrap': {'dcs': {'postgresql': {'parameters': {'wal_keep_segments': 100}}}}})
         if config['postgresql'].get('callbacks', {}).get('on_role_change'):
             config['postgresql']['callbacks']['on_role_change'] += ' ' + str(self.__PORT)
 
@@ -194,16 +206,16 @@ class PatroniController(AbstractController):
 
         user = config['postgresql'].get('authentication', config['postgresql']).get('superuser', {})
         self._connkwargs = {k: user[n] for n, k in [('username', 'user'), ('password', 'password')] if n in user}
-        self._connkwargs.update({'host': host, 'port': self.__PORT, 'database': 'postgres'})
+        self._connkwargs.update({'host': host, 'port': self.__PORT, 'dbname': 'postgres'})
 
         self._replication = config['postgresql'].get('authentication', config['postgresql']).get('replication', {})
-        self._replication.update({'host': host, 'port': self.__PORT, 'database': 'postgres'})
+        self._replication.update({'host': host, 'port': self.__PORT, 'dbname': 'postgres'})
 
         return patroni_config_path
 
     def _connection(self):
         if not self._conn or self._conn.closed != 0:
-            self._conn = psycopg2.connect(**self._connkwargs)
+            self._conn = psycopg.connect(**self._connkwargs)
             self._conn.autocommit = True
         return self._conn
 
@@ -217,7 +229,7 @@ class PatroniController(AbstractController):
             cursor = self._cursor()
             cursor.execute(query)
             return cursor
-        except psycopg2.Error:
+        except psycopg.Error:
             if not fail_ok:
                 raise
 
@@ -257,7 +269,7 @@ class PatroniController(AbstractController):
 
     @property
     def backup_source(self):
-        return 'postgres://{username}:{password}@{host}:{port}/{database}'.format(**self._replication)
+        return 'postgres://{username}:{password}@{host}:{port}/{dbname}'.format(**self._replication)
 
     def backup(self, dest=os.path.join('data', 'basebackup')):
         subprocess.call(PatroniPoolController.BACKUP_SCRIPT + ['--walmethod=none',
@@ -373,21 +385,36 @@ class ConsulController(AbstractDcsController):
         super(ConsulController, self).start(max_wait_limit)
 
 
-class EtcdController(AbstractDcsController):
+class AbstractEtcdController(AbstractDcsController):
 
     """ handles all etcd related tasks, used for the tests setup and cleanup """
 
-    def __init__(self, context):
-        super(EtcdController, self).__init__(context)
-        os.environ['PATRONI_ETCD_HOST'] = 'localhost:2379'
-
-        import etcd
-        self._client = etcd.Client(port=2379)
+    def __init__(self, context, client_cls):
+        super(AbstractEtcdController, self).__init__(context)
+        self._client_cls = client_cls
 
     def _start(self):
         return subprocess.Popen(["etcd", "--debug", "--data-dir", self._work_directory],
                                 stdout=self._log, stderr=subprocess.STDOUT)
 
+    def _is_running(self):
+        from patroni.dcs.etcd import DnsCachingResolver
+        # if etcd is running, but we didn't start it
+        try:
+            self._client = self._client_cls({'host': 'localhost', 'port': 2379, 'retry_timeout': 30,
+                                             'patronictl': 1}, DnsCachingResolver())
+            return True
+        except Exception:
+            return False
+
+
+class EtcdController(AbstractEtcdController):
+
+    def __init__(self, context):
+        from patroni.dcs.etcd import EtcdClient
+        super(EtcdController, self).__init__(context, EtcdClient)
+        os.environ['PATRONI_ETCD_HOST'] = 'localhost:2379'
+
     def query(self, key, scope='batman'):
         import etcd
         try:
@@ -404,12 +431,25 @@ class EtcdController(AbstractDcsController):
         except Exception as e:
             assert False, "exception when cleaning up etcd contents: {0}".format(e)
 
-    def _is_running(self):
-        # if etcd is running, but we didn't start it
+
+class Etcd3Controller(AbstractEtcdController):
+
+    def __init__(self, context):
+        from patroni.dcs.etcd3 import Etcd3Client
+        super(Etcd3Controller, self).__init__(context, Etcd3Client)
+        os.environ['PATRONI_ETCD3_HOST'] = 'localhost:2379'
+
+    def query(self, key, scope='batman'):
+        import base64
+        response = self._client.range(self.path(key, scope))
+        for k in response.get('kvs', []):
+            return base64.b64decode(k['value']).decode('utf-8') if 'value' in k else None
+
+    def cleanup_service_tree(self):
         try:
-            return bool(self._client.machines)
-        except Exception:
-            return False
+            self._client.deleteprefix(self.path(scope=''))
+        except Exception as e:
+            assert False, "exception when cleaning up etcd contents: {0}".format(e)
 
 
 class KubernetesController(AbstractDcsController):
@@ -421,8 +461,9 @@ class KubernetesController(AbstractDcsController):
         self._label_selector = ','.join('{0}={1}'.format(k, v) for k, v in self._labels.items())
         os.environ['PATRONI_KUBERNETES_LABELS'] = json.dumps(self._labels)
         os.environ['PATRONI_KUBERNETES_USE_ENDPOINTS'] = 'true'
+        os.environ['PATRONI_KUBERNETES_BYPASS_API_SERVICE'] = 'true'
 
-        from kubernetes import client as k8s_client, config as k8s_config
+        from patroni.dcs.kubernetes import k8s_client, k8s_config
         k8s_config.load_kube_config(context='local')
         self._client = k8s_client
         self._api = self._client.CoreV1Api()
@@ -524,11 +565,70 @@ class ZooKeeperController(AbstractDcsController):
             return False
 
 
+class MockExhibitor(BaseHTTPRequestHandler):
+
+    def do_GET(self):
+        self.send_response(200)
+        self.end_headers()
+        self.wfile.write(b'{"servers":["127.0.0.1"],"port":2181}')
+
+    def log_message(self, fmt, *args):
+        pass
+
+
 class ExhibitorController(ZooKeeperController):
 
     def __init__(self, context):
         super(ExhibitorController, self).__init__(context, False)
-        os.environ.update({'PATRONI_EXHIBITOR_HOSTS': 'localhost', 'PATRONI_EXHIBITOR_PORT': '8181'})
+        port = 8181
+        exhibitor = HTTPServer(('', port), MockExhibitor)
+        exhibitor.daemon_thread = True
+        exhibitor_thread = threading.Thread(target=exhibitor.serve_forever)
+        exhibitor_thread.daemon = True
+        exhibitor_thread.start()
+        os.environ.update({'PATRONI_EXHIBITOR_HOSTS': 'localhost', 'PATRONI_EXHIBITOR_PORT': str(port)})
+
+
+class RaftController(AbstractDcsController):
+
+    CONTROLLER_ADDR = 'localhost:1234'
+    PASSWORD = '12345'
+
+    def __init__(self, context):
+        super(RaftController, self).__init__(context)
+        os.environ.update(PATRONI_RAFT_PARTNER_ADDRS="'" + self.CONTROLLER_ADDR + "'",
+                          PATRONI_RAFT_PASSWORD=self.PASSWORD, RAFT_PORT='1234')
+        self._raft = None
+
+    def _start(self):
+        env = os.environ.copy()
+        del env['PATRONI_RAFT_PARTNER_ADDRS']
+        env['PATRONI_RAFT_SELF_ADDR'] = self.CONTROLLER_ADDR
+        env['PATRONI_RAFT_DATA_DIR'] = self._work_directory
+        return subprocess.Popen([sys.executable, '-m', 'coverage', 'run',
+                                '--source=patroni', '-p', 'patroni_raft_controller.py'],
+                                stdout=self._log, stderr=subprocess.STDOUT, env=env)
+
+    def query(self, key, scope='batman'):
+        ret = self._raft.get(self.path(key, scope))
+        return ret and ret['value']
+
+    def set(self, key, value):
+        self._raft.set(self.path(key), value)
+
+    def cleanup_service_tree(self):
+        from patroni.dcs.raft import KVStoreTTL
+
+        if self._raft:
+            self._raft.destroy()
+            self.stop()
+            os.makedirs(self._work_directory)
+            self.start()
+
+        ready_event = threading.Event()
+        self._raft = KVStoreTTL(ready_event.set, None, None, partner_addrs=[self.CONTROLLER_ADDR], password=self.PASSWORD)
+        self._raft.startAutoTick()
+        ready_event.wait()
 
 
 class PatroniPoolController(object):
@@ -770,11 +870,11 @@ class WatchdogMonitor(object):
         return triggered
 
 
-# actions to execute on start/stop of the tests and before running invidual features
+# actions to execute on start/stop of the tests and before running individual features
 def before_all(context):
     os.environ.update({'PATRONI_RESTAPI_USERNAME': 'username', 'PATRONI_RESTAPI_PASSWORD': 'password'})
-    context.ci = 'TRAVIS_BUILD_NUMBER' in os.environ or 'BUILD_NUMBER' in os.environ
-    context.timeout_multiplier = 2 if context.ci else 1
+    context.ci = any(a in os.environ for a in ('TRAVIS_BUILD_NUMBER', 'BUILD_NUMBER', 'GITHUB_ACTIONS'))
+    context.timeout_multiplier = 5 if context.ci else 1  # MacOS sometimes is VERY slow
     context.pctl = PatroniPoolController(context)
     context.dcs_ctl = context.pctl.known_dcs[context.pctl.dcs](context)
     context.dcs_ctl.start()

features/ignored_slots.feature

@@ -0,0 +1,61 @@
+Feature: ignored slots
+  Scenario: check ignored slots aren't removed on failover/switchover
+    Given I start postgres1
+    Then postgres1 is a leader after 10 seconds
+    And there is a non empty initialize key in DCS after 15 seconds
+    When I issue a PATCH request to http://127.0.0.1:8009/config with {"loop_wait": 2, "ignore_slots": [{"name": "unmanaged_slot_0", "database": "postgres", "plugin": "test_decoding", "type": "logical"}, {"name": "unmanaged_slot_1", "database": "postgres", "plugin": "test_decoding"}, {"name": "unmanaged_slot_2", "database": "postgres"}, {"name": "unmanaged_slot_3"}], "postgresql": {"parameters": {"wal_level": "logical"}}}
+    Then I receive a response code 200
+    And Response on GET http://127.0.0.1:8009/config contains ignore_slots after 10 seconds
+    # Make sure the wal_level has been changed.
+    When I shut down postgres1
+    And I start postgres1
+    Then postgres1 is a leader after 10 seconds
+    And "members/postgres1" key in DCS has role=master after 3 seconds
+    # Make sure Patroni has finished telling Postgres it should be accepting writes.
+    And postgres1 role is the primary after 20 seconds
+    # 1. Create our test logical replication slot.
+    # Test that ny subset of attributes in the ignore slots matcher is enough to match a slot
+    # by using 3 different slots.
+    When I create a logical replication slot unmanaged_slot_0 on postgres1 with the test_decoding plugin
+    And I create a logical replication slot unmanaged_slot_1 on postgres1 with the test_decoding plugin
+    And I create a logical replication slot unmanaged_slot_2 on postgres1 with the test_decoding plugin
+    And I create a logical replication slot unmanaged_slot_3 on postgres1 with the test_decoding plugin
+    And I create a logical replication slot dummy_slot on postgres1 with the test_decoding plugin
+    # It seems like it'd be obvious that these slots exist since we just created them,
+    # but Patroni can actually end up dropping them almost immediately, so it's helpful
+    # to verify they exist before we begin testing whether they persist through failover
+    # cycles.
+    Then postgres1 has a logical replication slot named unmanaged_slot_0 with the test_decoding plugin
+    And postgres1 has a logical replication slot named unmanaged_slot_1 with the test_decoding plugin
+    And postgres1 has a logical replication slot named unmanaged_slot_2 with the test_decoding plugin
+    And postgres1 has a logical replication slot named unmanaged_slot_3 with the test_decoding plugin
+
+    When I start postgres0
+    Then "members/postgres0" key in DCS has role=replica after 3 seconds
+    And postgres0 role is the secondary after 20 seconds
+    # Verify that the replica has advanced beyond the point in the WAL
+    # where we created the replication slot so that on the next failover
+    # cycle we don't accidentally rewind to before the slot creation.
+    And replication works from postgres1 to postgres0 after 20 seconds
+    When I shut down postgres1
+    Then "members/postgres0" key in DCS has role=master after 3 seconds
+
+    # 2. After a failover the server (now a replica) still has the slot.
+    When I start postgres1
+    Then postgres1 role is the secondary after 20 seconds
+    And "members/postgres1" key in DCS has role=replica after 3 seconds
+    # give Patroni time to sync replication slots
+    And I sleep for 2 seconds
+    And postgres1 has a logical replication slot named unmanaged_slot_0 with the test_decoding plugin
+    And postgres1 has a logical replication slot named unmanaged_slot_1 with the test_decoding plugin
+    And postgres1 has a logical replication slot named unmanaged_slot_2 with the test_decoding plugin
+    And postgres1 has a logical replication slot named unmanaged_slot_3 with the test_decoding plugin
+    And postgres1 does not have a logical replication slot named dummy_slot
+
+    # 3. After a failover the server (now a master) still has the slot.
+    When I shut down postgres0
+    Then "members/postgres1" key in DCS has role=master after 3 seconds
+    And postgres1 has a logical replication slot named unmanaged_slot_0 with the test_decoding plugin
+    And postgres1 has a logical replication slot named unmanaged_slot_1 with the test_decoding plugin
+    And postgres1 has a logical replication slot named unmanaged_slot_2 with the test_decoding plugin
+    And postgres1 has a logical replication slot named unmanaged_slot_3 with the test_decoding plugin

features/patroni_api.feature

@@ -8,6 +8,8 @@ Scenario: check API requests on a stand-alone server
 	Then I receive a response code 200
 	And I receive a response state running
 	And I receive a response role master
+	When I issue a GET request to http://127.0.0.1:8008/standby_leader
+	Then I receive a response code 503
 	When I issue a GET request to http://127.0.0.1:8008/health
 	Then I receive a response code 200
 	When I issue a GET request to http://127.0.0.1:8008/replica
@@ -59,10 +61,17 @@ Scenario: check the scheduled restart
 		And postgres0 role is the primary after 10 seconds
 
 Scenario: check API requests for the primary-replica pair in the pause mode
-	Given I run patronictl.py pause batman
-	Then I receive a response returncode 0
-	When I start postgres1
+	Given I start postgres1
 	Then replication works from postgres0 to postgres1 after 20 seconds
+	When I run patronictl.py pause batman
+	Then I receive a response returncode 0
+	When I kill postmaster on postgres1
+	And I issue a GET request to http://127.0.0.1:8009/replica
+	Then I receive a response code 503
+	When I run patronictl.py restart batman postgres1 --force
+	Then I receive a response returncode 0
+	Then replication works from postgres0 to postgres1 after 20 seconds
+	And I sleep for 2 seconds
 	When I issue a GET request to http://127.0.0.1:8009/replica
 	Then I receive a response code 200
 	And I receive a response state running

features/standby_cluster.feature

@@ -1,5 +1,5 @@
 Feature: standby cluster
-  Scenario: check permanent logical slots are preserved on failover/switchover
+  Scenario: prepare the cluster with logical slots
     Given I start postgres1
     Then postgres1 is a leader after 10 seconds
     And there is a non empty initialize key in DCS after 15 seconds
@@ -10,23 +10,33 @@ Feature: standby cluster
     When I issue a PATCH request to http://127.0.0.1:8009/config with {"slots": {"test_logical": {"type": "logical", "database": "postgres", "plugin": "test_decoding"}}}
     Then I receive a response code 200
     And I do a backup of postgres1
-    When I start postgres0 with callback configured
+    When I start postgres0
     Then "members/postgres0" key in DCS has state=running after 10 seconds
     And replication works from postgres1 to postgres0 after 15 seconds
+
+  @skip
+  Scenario: check permanent logical slots are synced to the replica
+    Given I run patronictl.py restart batman postgres1 --force
+    Then Logical slot test_logical is in sync between postgres0 and postgres1 after 10 seconds
+    When I add the table replicate_me to postgres1
+    And I get all changes from logical slot test_logical on postgres1
+    Then Logical slot test_logical is in sync between postgres0 and postgres1 after 10 seconds
+
+  Scenario: Detach exiting node from the cluster
     When I shut down postgres1
     Then postgres0 is a leader after 10 seconds
     And "members/postgres0" key in DCS has role=master after 3 seconds
     When I issue a GET request to http://127.0.0.1:8008/
     Then I receive a response code 200
-    And there is a label with "test_logical" in postgres0 data directory
 
   Scenario: check replication of a single table in a standby cluster
     Given I start postgres1 in a standby cluster batman1 as a clone of postgres0
     Then postgres1 is a leader of batman1 after 10 seconds
     When I add the table foo to postgres0
     Then table foo is present on postgres1 after 20 seconds
+    And I sleep for 3 seconds
     When I issue a GET request to http://127.0.0.1:8009/master
-    Then I receive a response code 200
+    Then I receive a response code 503
     When I issue a GET request to http://127.0.0.1:8009/standby_leader
     Then I receive a response code 200
     And I receive a response role standby_leader
@@ -34,13 +44,15 @@ Feature: standby cluster
     When I start postgres2 in a cluster batman1
     Then postgres2 role is the replica after 24 seconds
     And table foo is present on postgres2 after 20 seconds
+    And postgres1 does not have a logical replication slot named test_logical
 
   Scenario: check failover
     When I kill postgres1
     And I kill postmaster on postgres1
     Then postgres2 is replicating from postgres0 after 32 seconds
     When I issue a GET request to http://127.0.0.1:8010/master
-    Then I receive a response code 200
+    Then I receive a response code 503
+    And I sleep for 3 seconds
     When I issue a GET request to http://127.0.0.1:8010/standby_leader
     Then I receive a response code 200
     And I receive a response role standby_leader

features/steps/basic_replication.py

@@ -1,4 +1,4 @@
-import psycopg2 as pg
+import patroni.psycopg as pg
 
 from behave import step, then
 from time import sleep, time
@@ -33,6 +33,37 @@ def add_table(context, table_name, pg_name):
         assert False, "Error creating table {0} on {1}: {2}".format(table_name, pg_name, e)
 
 
+@step('I {action:w} wal replay on {pg_name:w}')
+def toggle_wal_replay(context, action, pg_name):
+    # pause or resume the wal replay process
+    try:
+       version = context.pctl.query(pg_name, "select pg_catalog.pg_read_file('PG_VERSION', 0, 2)").fetchone()
+       wal = version and version[0] and int(version[0].split('.')[0]) < 10 and "xlog" or "wal"
+       context.pctl.query(pg_name, "SELECT pg_{0}_replay_{1}()".format(wal, action))
+    except pg.Error as e:
+        assert False, "Error during {0} wal recovery on {1}: {2}".format(action, pg_name, e)
+
+
+@step('I {action:w} table on {pg_name:w}')
+def crdr_mytest(context, action, pg_name):
+    try:
+       if (action == "create"):
+           context.pctl.query(pg_name, "create table if not exists mytest(id Numeric)")
+       else:
+           context.pctl.query(pg_name, "drop table if exists mytest")
+    except pg.Error as e:
+        assert False, "Error {0} table mytest on {1}: {2}".format(action, pg_name, e)
+
+
+@step('I load data on {pg_name:w}')
+def initiate_load(context, pg_name):
+    # perform dummy load
+    try:
+       context.pctl.query(pg_name, "begin; insert into mytest select r::numeric from generate_series(1, 350000) r; commit;")
+    except pg.Error as e:
+        assert False, "Error loading test data on {0}: {1}".format(pg_name, e)
+
+
 @then('Table {table_name:w} is present on {pg_name:w} after {max_replication_delay:d} seconds')
 def table_is_present_on(context, table_name, pg_name, max_replication_delay):
     max_replication_delay *= context.timeout_multiplier

features/steps/cascading_replication.py

@@ -12,8 +12,10 @@ def start_patroni_with_a_name_value_tag(context, name, tag_name, tag_value):
 @then('There is a {label} with "{content}" in {name:w} data directory')
 def check_label(context, label, content, name):
     label = context.pctl.read_label(name, label)
+    if label is None:
+        label = ""
     label = label.replace('\n', '\\n')
-    assert content in label, "{0} doesn't contain {1}".format(label, content)
+    assert content in label, "\"{0}\" doesn't contain {1}".format(label, content)
 
 
 @step('I create label with "{content:w}" in {name:w} data directory')
@@ -21,19 +23,22 @@ def write_label(context, content, name):
     context.pctl.write_label(name, content)
 
 
-@step('"{name}" key in DCS has {key:w}={value:w} after {time_limit:d} seconds')
+@step('"{name}" key in DCS has {key:w}={value} after {time_limit:d} seconds')
 def check_member(context, name, key, value, time_limit):
     time_limit *= context.timeout_multiplier
     max_time = time.time() + int(time_limit)
+    dcs_value = None
     while time.time() < max_time:
         try:
             response = json.loads(context.dcs_ctl.query(name))
-            if response.get(key) == value:
+            dcs_value = response.get(key)
+            if dcs_value == value:
                 return
         except Exception:
             pass
         time.sleep(1)
-    assert False, "{0} does not have {1}={2} in dcs after {3} seconds".format(name, key, value, time_limit)
+    assert False, "{0} does not have {1}={2} (found {3}) in dcs after {4} seconds".format(name, key, value,
+                                                                                          dcs_value, time_limit)
 
 
 @step('there is a non empty {key:w} key in DCS after {time_limit:d} seconds')

features/steps/slots.py

@@ -0,0 +1,60 @@
+import time
+
+from behave import step, then
+import patroni.psycopg as pg
+
+
+@step('I create a logical replication slot {slot_name} on {pg_name:w} with the {plugin:w} plugin')
+def create_logical_replication_slot(context, slot_name, pg_name, plugin):
+    try:
+        output = context.pctl.query(pg_name, ("SELECT pg_create_logical_replication_slot('{0}', '{1}'),"
+                                              " current_database()").format(slot_name, plugin))
+        print(output.fetchone())
+    except pg.Error as e:
+        print(e)
+        assert False, "Error creating slot {0} on {1} with plugin {2}".format(slot_name, pg_name, plugin)
+
+
+@then('{pg_name:w} has a logical replication slot named {slot_name} with the {plugin:w} plugin')
+def has_logical_replication_slot(context, pg_name, slot_name, plugin):
+    try:
+        row = context.pctl.query(pg_name, ("SELECT slot_type, plugin FROM pg_replication_slots"
+                                           " WHERE slot_name = '{0}'").format(slot_name)).fetchone()
+        assert row, "Couldn't find replication slot named {0}".format(slot_name)
+        assert row[0] == "logical", "Found replication slot named {0} but wasn't a logical slot".format(slot_name)
+        assert row[1] == plugin, ("Found replication slot named {0} but was using plugin "
+                                  "{1} rather than {2}").format(slot_name, row[1], plugin)
+    except pg.Error:
+        assert False, "Error looking for slot {0} on {1} with plugin {2}".format(slot_name, pg_name, plugin)
+
+
+@then('{pg_name:w} does not have a logical replication slot named {slot_name}')
+def does_not_have_logical_replication_slot(context, pg_name, slot_name):
+    try:
+        row = context.pctl.query(pg_name, ("SELECT 1 FROM pg_replication_slots"
+                                           " WHERE slot_name = '{0}'").format(slot_name)).fetchone()
+        assert not row, "Found unexpected replication slot named {0}".format(slot_name)
+    except pg.Error:
+        assert False, "Error looking for slot {0} on {1}".format(slot_name, pg_name)
+
+
+@step('Logical slot {slot_name:w} is in sync between {pg_name1:w} and {pg_name2:w} after {time_limit:d} seconds')
+def logical_slots_in_sync(context, slot_name, pg_name1, pg_name2, time_limit):
+    time_limit *= context.timeout_multiplier
+    max_time = time.time() + int(time_limit)
+    while time.time() < max_time:
+        try:
+            query = "SELECT confirmed_flush_lsn FROM pg_replication_slots WHERE slot_name = '{0}'".format(slot_name)
+            slot1 = context.pctl.query(pg_name1, query).fetchone()
+            slot2 = context.pctl.query(pg_name2, query).fetchone()
+            if slot1[0] == slot2[0]:
+                return
+        except Exception:
+            pass
+        time.sleep(1)
+    assert False, "Logical slot {0} is not in sync between {1} and {2}".format(slot_name, pg_name1, pg_name2)
+
+
+@step('I get all changes from logical slot {slot_name:w} on {pg_name:w}')
+def logical_slot_get_changes(context, slot_name, pg_name):
+    context.pctl.query(pg_name, "SELECT * FROM pg_logical_slot_get_changes('{0}', NULL, NULL)".format(slot_name))

features/steps/standby_cluster.py

@@ -10,18 +10,8 @@ SELECT * FROM pg_catalog.pg_stat_replication
 WHERE application_name = '{0}'
 """
 
-callback = sys.executable + " features/callback2.py "
-
-
-@step('I start {name:w} with callback configured')
-def start_patroni_with_callbacks(context, name):
-    return context.pctl.start(name, custom_config={
-        "postgresql": {
-            "callbacks": {
-                "on_role_change": sys.executable + " features/callback.py"
-            }
-        }
-    })
+executable = sys.executable if os.name != 'nt' else sys.executable.replace('\\', '/')
+callback = executable + " features/callback2.py "
 
 
 @step('I start {name:w} in a cluster {cluster_name:w}')
@@ -31,7 +21,7 @@ def start_patroni(context, name, cluster_name):
         "postgresql": {
             "callbacks": {c: callback + name for c in ('on_start', 'on_stop', 'on_restart', 'on_role_change')},
             "backup_restore": {
-                "command": (sys.executable + " features/backup_restore.py --sourcedir=" +
+                "command": (executable + " features/backup_restore.py --sourcedir=" +
                             os.path.join(context.pctl.patroni_path, 'data', 'basebackup'))}
         }
     })
@@ -54,7 +44,8 @@ def start_patroni_standby_cluster(context, name, cluster_name, name2):
                     "port": port,
                     "primary_slot_name": "pm_1",
                     "create_replica_methods": ["backup_restore", "basebackup"]
-                }
+                },
+                "postgresql": {"parameters": {"wal_level": "logical"}}
             }
         },
         "postgresql": {

kubernetes/entrypoint.sh

@@ -33,7 +33,5 @@ postgresql:
 __EOF__
 
 unset PATRONI_SUPERUSER_PASSWORD PATRONI_REPLICATION_PASSWORD
-export KUBERNETES_NAMESPACE=$PATRONI_KUBERNETES_NAMESPACE
-export POD_NAME=$PATRONI_NAME
 
-exec /usr/bin/python3 /usr/local/bin/patroni /home/postgres/patroni.yml
+exec /usr/bin/python3 /usr/local/bin/patroni /home/postgres/patroni.yml

kubernetes/openshift-example/templates/template_patroni_ephemeral.yml

@@ -118,6 +118,8 @@ objects:
               fieldRef:
                 apiVersion: v1
                 fieldPath: metadata.namespace
+          - name: PATRONI_KUBERNETES_BYPASS_API_SERVICE
+            value: 'true'
           - name: PATRONI_KUBERNETES_LABELS
             value: '{application: ${APPLICATION_NAME}, cluster-name: ${PATRONI_CLUSTER_NAME}}'
           - name: PATRONI_SUPERUSER_USERNAME
@@ -152,6 +154,16 @@ objects:
           image: docker-registry.default.svc:5000/${NAMESPACE}/patroni:latest
           imagePullPolicy: IfNotPresent
           name: ${APPLICATION_NAME}
+          readinessProbe:
+            httpGet:
+              scheme: HTTP
+              path: /readiness
+              port: 8008
+            initialDelaySeconds: 3
+            periodSeconds: 10
+            timeoutSeconds: 5
+            successThreshold: 1
+            failureThreshold: 3
           ports:
           - containerPort: 8008
             protocol: TCP
@@ -240,6 +252,34 @@ objects:
   subjects:
   - kind: ServiceAccount
     name: ${SERVICE_ACCOUNT}
+# Following privileges are only required if deployed not in the "default"
+# namespace and you want Patroni to bypass kubernetes service
+# (PATRONI_KUBERNETES_BYPASS_API_SERVICE=true)
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRole
+  metadata:
+    name: patroni-k8s-ep-access
+  rules:
+  - apiGroups:
+    - ""
+    resources:
+    - endpoints
+    resourceNames:
+    - kubernetes
+    verbs:
+    - get
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRoleBinding
+  metadata:
+    name: ${NAMESPACE}-${SERVICE_ACCOUNT}-k8s-ep-access
+  roleRef:
+    apiGroup: rbac.authorization.k8s.io
+    kind: ClusterRole
+    name: patroni-k8s-ep-access
+  subjects:
+  - kind: ServiceAccount
+    name: ${SERVICE_ACCOUNT}
+    namespace: ${NAMESPACE}
 parameters:
 - description: The name of the application for labelling all artifacts.
   displayName: Application Name

kubernetes/openshift-example/templates/template_patroni_persistent.yaml

@@ -5,11 +5,9 @@ metadata:
   annotations:
     description: |-
       Patroni Postgresql database cluster, with persistent storage.
-
-      WARNING: Any data stored will be lost upon pod destruction. Only use this template for testing.
     iconClass: icon-postgresql
     openshift.io/display-name: Patroni Postgresql (Persistent)
-    openshift.io/long-description: This template deploys a a patroni postgresql HA cluster without persistent storage.
+    openshift.io/long-description: This template deploys a a patroni postgresql HA cluster with persistent storage.
     tags: postgresql
 objects:
 - apiVersion: v1
@@ -132,6 +130,8 @@ objects:
               fieldRef:
                 apiVersion: v1
                 fieldPath: metadata.namespace
+          - name: PATRONI_KUBERNETES_BYPASS_API_SERVICE
+            value: 'true'
           - name: PATRONI_KUBERNETES_LABELS
             value: '{application: ${APPLICATION_NAME}, cluster-name: ${PATRONI_CLUSTER_NAME}}'
           - name: PATRONI_SUPERUSER_USERNAME
@@ -166,6 +166,16 @@ objects:
           image: docker-registry.default.svc:5000/${NAMESPACE}/patroni:latest
           imagePullPolicy: IfNotPresent
           name: ${APPLICATION_NAME}
+          readinessProbe:
+            httpGet:
+              scheme: HTTP
+              path: /readiness
+              port: 8008
+            initialDelaySeconds: 3
+            periodSeconds: 10
+            timeoutSeconds: 5
+            successThreshold: 1
+            failureThreshold: 3
           ports:
           - containerPort: 8008
             protocol: TCP
@@ -266,6 +276,34 @@ objects:
   subjects:
   - kind: ServiceAccount
     name: ${SERVICE_ACCOUNT}
+# Following privileges are only required if deployed not in the "default"
+# namespace and you want Patroni to bypass kubernetes service
+# (PATRONI_KUBERNETES_BYPASS_API_SERVICE=true)
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRole
+  metadata:
+    name: patroni-k8s-ep-access
+  rules:
+  - apiGroups:
+    - ""
+    resources:
+    - endpoints
+    resourceNames:
+    - kubernetes
+    verbs:
+    - get
+- apiVersion: rbac.authorization.k8s.io/v1
+  kind: ClusterRoleBinding
+  metadata:
+    name: ${NAMESPACE}-${SERVICE_ACCOUNT}-k8s-ep-access
+  roleRef:
+    apiGroup: rbac.authorization.k8s.io
+    kind: ClusterRole
+    name: patroni-k8s-ep-access
+  subjects:
+  - kind: ServiceAccount
+    name: ${SERVICE_ACCOUNT}
+    namespace: ${NAMESPACE}
 parameters:
 - description: The name of the application for labelling all artifacts.
   displayName: Application Name
@@ -314,4 +352,4 @@ parameters:
 - description: The size of the persistent volume to create. 
   displayName: Persistent Volume Size
   name: PVC_SIZE
-  value: 5Gi
+  value: 5Gi

kubernetes/patroni_k8s.yaml

@@ -10,7 +10,7 @@ spec:
   clusterIP: None
 
 ---
-apiVersion: apps/v1beta1
+apiVersion: apps/v1
 kind: StatefulSet
 metadata:
   name: &cluster_name patronidemo
@@ -20,6 +20,10 @@ metadata:
 spec:
   replicas: 3
   serviceName: *cluster_name
+  selector:
+    matchLabels:
+      application: patroni
+      cluster-name: *cluster_name
   template:
     metadata:
       labels:
@@ -31,6 +35,16 @@ spec:
       - name: *cluster_name
         image: patroni  # docker build -t patroni .
         imagePullPolicy: IfNotPresent
+        readinessProbe:
+          httpGet:
+            scheme: HTTP
+            path: /readiness
+            port: 8008
+          initialDelaySeconds: 3
+          periodSeconds: 10
+          timeoutSeconds: 5
+          successThreshold: 1
+          failureThreshold: 3
         ports:
         - containerPort: 8008
           protocol: TCP
@@ -48,6 +62,8 @@ spec:
           valueFrom:
             fieldRef:
               fieldPath: metadata.namespace
+        - name: PATRONI_KUBERNETES_BYPASS_API_SERVICE
+          value: 'true'
         - name: PATRONI_KUBERNETES_USE_ENDPOINTS
           value: 'true'
         - name: PATRONI_KUBERNETES_LABELS
@@ -123,6 +139,25 @@ spec:
   - port: 5432
     targetPort: 5432
 
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: patronidemo-repl
+  labels:
+    application: patroni
+    cluster-name:  &cluster_name patronidemo
+    role: replica
+spec:
+  type: ClusterIP
+  selector:
+    application: patroni
+    cluster-name: *cluster_name
+    role: replica
+  ports:
+  - port: 5432
+    targetPort: 5432
+
 ---
 apiVersion: v1
 kind: Secret
@@ -210,3 +245,37 @@ roleRef:
 subjects:
 - kind: ServiceAccount
   name: patronidemo
+
+# Following privileges are only required if deployed not in the "default"
+# namespace and you want Patroni to bypass kubernetes service
+# (PATRONI_KUBERNETES_BYPASS_API_SERVICE=true)
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: patroni-k8s-ep-access
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - endpoints
+  resourceNames:
+  - kubernetes
+  verbs:
+  - get
+
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: patroni-k8s-ep-access
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: patroni-k8s-ep-access
+subjects:
+- kind: ServiceAccount
+  name: patronidemo
+# The namespace must be specified explicitly.
+# If deploying to the different namespace you have to change it.
+  namespace: default

patroni/__init__.py

@@ -4,31 +4,29 @@ import signal
 import sys
 import time
 
-from patroni.version import __version__
+from .daemon import AbstractPatroniDaemon, abstract_main
+from .version import __version__
 
 logger = logging.getLogger(__name__)
 
 PATRONI_ENV_PREFIX = 'PATRONI_'
 KUBERNETES_ENV_PREFIX = 'KUBERNETES_'
+MIN_PSYCOPG2 = (2, 5, 4)
 
 
-class Patroni(object):
+class Patroni(AbstractPatroniDaemon):
 
-    def __init__(self, conf):
+    def __init__(self, config):
         from patroni.api import RestApiServer
         from patroni.dcs import get_dcs
         from patroni.ha import Ha
-        from patroni.log import PatroniLogger
         from patroni.postgresql import Postgresql
         from patroni.request import PatroniRequest
         from patroni.watchdog import Watchdog
 
-        self.setup_signal_handlers()
+        super(Patroni, self).__init__(config)
 
         self.version = __version__
-        self.logger = PatroniLogger()
-        self.config = conf
-        self.logger.reload_config(self.config.get('log', {}))
         self.dcs = get_dcs(self.config)
         self.watchdog = Watchdog(self.config)
         self.load_dynamic_configuration()
@@ -71,14 +69,15 @@ class Patroni(object):
     def nosync(self):
         return bool(self.tags.get('nosync', False))
 
-    def reload_config(self, sighup=False):
+    def reload_config(self, sighup=False, local=False):
         try:
-            self.tags = self.get_tags()
-            self.logger.reload_config(self.config.get('log', {}))
-            self.watchdog.reload_config(self.config)
-            if sighup:
+            super(Patroni, self).reload_config(sighup, local)
+            if local:
+                self.tags = self.get_tags()
                 self.request.reload_config(self.config)
-            self.api.reload_config(self.config['restapi'])
+            if local or sighup and self.api.reload_local_certificate():
+                self.api.reload_config(self.config['restapi'])
+            self.watchdog.reload_config(self.config)
             self.postgresql.reload_config(self.config['postgresql'], sighup)
             self.dcs.reload_config(self.config)
         except Exception:
@@ -88,15 +87,6 @@ class Patroni(object):
     def replicatefrom(self):
         return self.tags.get('replicatefrom')
 
-    def sighup_handler(self, *args):
-        self._received_sighup = True
-
-    def sigterm_handler(self, *args):
-        with self._sigterm_lock:
-            if not self._received_sigterm:
-                self._received_sigterm = True
-                sys.exit()
-
     @property
     def noloadbalance(self):
         return bool(self.tags.get('noloadbalance', False))
@@ -114,48 +104,24 @@ class Patroni(object):
         elif self.ha.watch(nap_time):
             self.next_run = time.time()
 
-    @property
-    def received_sigterm(self):
-        with self._sigterm_lock:
-            return self._received_sigterm
-
     def run(self):
         self.api.start()
-        self.logger.start()
         self.next_run = time.time()
+        super(Patroni, self).run()
 
-        while not self.received_sigterm:
-            if self._received_sighup:
-                self._received_sighup = False
-                if self.config.reload_local_configuration():
-                    self.reload_config(True)
-                else:
-                    self.postgresql.config.reload_config(self.config['postgresql'], True)
+    def _run_cycle(self):
+        logger.info(self.ha.run_cycle())
 
-            logger.info(self.ha.run_cycle())
+        if self.dcs.cluster and self.dcs.cluster.config and self.dcs.cluster.config.data \
+                and self.config.set_dynamic_configuration(self.dcs.cluster.config):
+            self.reload_config()
 
-            if self.dcs.cluster and self.dcs.cluster.config and self.dcs.cluster.config.data \
-                    and self.config.set_dynamic_configuration(self.dcs.cluster.config):
-                self.reload_config()
+        if self.postgresql.role != 'uninitialized':
+            self.config.save_cache()
 
-            if self.postgresql.role != 'uninitialized':
-                self.config.save_cache()
+        self.schedule_next_run()
 
-            self.schedule_next_run()
-
-    def setup_signal_handlers(self):
-        from threading import Lock
-
-        self._received_sighup = False
-        self._sigterm_lock = Lock()
-        self._received_sigterm = False
-        if os.name != 'nt':
-            signal.signal(signal.SIGHUP, self.sighup_handler)
-        signal.signal(signal.SIGTERM, self.sigterm_handler)
-
-    def shutdown(self):
-        with self._sigterm_lock:
-            self._received_sigterm = True
+    def _shutdown(self):
         try:
             self.api.shutdown()
         except Exception:
@@ -164,43 +130,14 @@ class Patroni(object):
             self.ha.shutdown()
         except Exception:
             logger.exception('Exception during Ha.shutdown')
-        self.logger.shutdown()
 
 
 def patroni_main():
-    import argparse
-
     from multiprocessing import freeze_support
-    from patroni.config import Config, ConfigParseError
     from patroni.validator import schema
 
     freeze_support()
-
-    parser = argparse.ArgumentParser()
-    parser.add_argument('--version', action='version', version='%(prog)s {0}'.format(__version__))
-    parser.add_argument('--validate-config', action='store_true', help='Run config validator and exit')
-    parser.add_argument('configfile', nargs='?', default='',
-                        help='Patroni may also read the configuration from the {0} environment variable'
-                        .format(Config.PATRONI_CONFIG_VARIABLE))
-    args = parser.parse_args()
-    try:
-        if args.validate_config:
-            conf = Config(args.configfile, validator=schema)
-            sys.exit()
-        else:
-            conf = Config(args.configfile)
-    except ConfigParseError as e:
-        if e.value:
-            print(e.value)
-        parser.print_help()
-        sys.exit(1)
-    patroni = Patroni(conf)
-    try:
-        patroni.run()
-    except KeyboardInterrupt:
-        pass
-    finally:
-        patroni.shutdown()
+    abstract_main(Patroni, schema)
 
 
 def fatal(string, *args):
@@ -208,30 +145,40 @@ def fatal(string, *args):
     sys.exit(1)
 
 
-def check_psycopg2():
-    min_psycopg2 = (2, 5, 4)
-    min_psycopg2_str = '.'.join(map(str, min_psycopg2))
-
-    def parse_version(version):
+def parse_version(version):
+    def _parse_version(version):
         for e in version.split('.'):
             try:
                 yield int(e)
             except ValueError:
                 break
+    return tuple(_parse_version(version.split(' ')[0]))
+
+
+# We pass MIN_PSYCOPG2 and parse_version as arguments to simplify usage of check_psycopg from the setup.py
+def check_psycopg(_min_psycopg2=MIN_PSYCOPG2, _parse_version=parse_version):
+    min_psycopg2_str = '.'.join(map(str, _min_psycopg2))
 
     try:
-        import psycopg2
-        version_str = psycopg2.__version__.split(' ')[0]
-        version = tuple(parse_version(version_str))
-        if version < min_psycopg2:
-            fatal('Patroni requires psycopg2>={0}, but only {1} is available', min_psycopg2_str, version_str)
+        from psycopg2 import __version__
+        if _parse_version(__version__) >= _min_psycopg2:
+            return
+        version_str = __version__.split(' ')[0]
     except ImportError:
-        fatal('Patroni requires psycopg2>={0} or psycopg2-binary', min_psycopg2_str)
+        version_str = None
+
+    try:
+        from psycopg import __version__
+    except ImportError:
+        error = 'Patroni requires psycopg2>={0}, psycopg2-binary, or psycopg>=3.0'.format(min_psycopg2_str)
+        if version_str:
+            error += ', but only psycopg2=={0} is available'.format(version_str)
+        fatal(error)
 
 
 def main():
     if os.getpid() != 1:
-        check_psycopg2()
+        check_psycopg()
         return patroni_main()
 
     # Patroni started with PID=1, it looks like we are in the container

patroni/api.py

@@ -1,7 +1,7 @@
 import base64
+import hmac
 import json
 import logging
-import psycopg2
 import time
 import traceback
 import dateutil.parser
@@ -9,20 +9,34 @@ import datetime
 import os
 import six
 import socket
+import sys
 
-from patroni.exceptions import PostgresConnectionException, PostgresException
-from patroni.postgresql.misc import postgres_version_to_int
-from patroni.utils import deep_compare, parse_bool, patch_config, Retry, \
-    RetryFailedError, parse_int, split_host_port, tzutc, uri, cluster_as_json
+from ipaddress import ip_address, ip_network as _ip_network
 from six.moves.BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 from six.moves.socketserver import ThreadingMixIn
+from six.moves.urllib_parse import urlparse, parse_qs
 from threading import Thread
 
+from . import psycopg
+from .exceptions import PostgresConnectionException, PostgresException
+from .postgresql.misc import postgres_version_to_int
+from .utils import deep_compare, enable_keepalive, parse_bool, patch_config, Retry, \
+    RetryFailedError, parse_int, split_host_port, tzutc, uri, cluster_as_json
+
 logger = logging.getLogger(__name__)
 
 
+def ip_network(value):
+    return _ip_network(value.decode('utf-8') if six.PY2 else value, False)
+
+
 class RestApiHandler(BaseHTTPRequestHandler):
 
+    def _write_status_code_only(self, status_code):
+        message = self.responses[status_code][0]
+        self.wfile.write('{0} {1} {2}\r\n\r\n'.format(self.protocol_version, status_code, message).encode('utf-8'))
+        self.log_request(status_code)
+
     def _write_response(self, status_code, body, content_type='text/html', headers=None):
         self.send_response(status_code)
         headers = headers or {}
@@ -30,23 +44,25 @@ class RestApiHandler(BaseHTTPRequestHandler):
             headers['Content-Type'] = content_type
         for name, value in headers.items():
             self.send_header(name, value)
+        for name, value in self.server.http_extra_headers.items():
+            self.send_header(name, value)
         self.end_headers()
         self.wfile.write(body.encode('utf-8'))
 
     def _write_json_response(self, status_code, response):
-        self._write_response(status_code, json.dumps(response), content_type='application/json')
+        self._write_response(status_code, json.dumps(response, default=str), content_type='application/json')
 
-    def check_auth(func):
-        """Decorator function to check authorization header or client certificates
+    def check_access(func):
+        """Decorator function to check the source ip, authorization header. or client certificates
 
         Usage example:
-        @check_auth
+        @check_access
         def do_PUT_foo():
             pass
         """
 
         def wrapper(self, *args, **kwargs):
-            if self.server.check_auth(self):
+            if self.server.check_access(self):
                 return func(self, *args, **kwargs)
 
         return wrapper
@@ -80,61 +96,109 @@ class RestApiHandler(BaseHTTPRequestHandler):
     def do_GET(self, write_status_code_only=False):
         """Default method for processing all GET requests which can not be routed to other methods"""
 
-        time_start = time.time()
-        request_type = 'OPTIONS' if write_status_code_only else 'GET'
-
         path = '/master' if self.path == '/' else self.path
         response = self.get_postgresql_status()
 
         patroni = self.server.patroni
         cluster = patroni.dcs.cluster
 
-        if not cluster and patroni.ha.is_paused():
-            primary_status_code = 200 if response['role'] == 'master' else 503
-        else:
-            primary_status_code = 200 if patroni.ha.is_leader() else 503
+        leader_optime = cluster and cluster.last_lsn or 0
+        replayed_location = response.get('xlog', {}).get('replayed_location', 0)
+        max_replica_lag = parse_int(self.path_query.get('lag', [sys.maxsize])[0], 'B')
+        if max_replica_lag is None:
+            max_replica_lag = sys.maxsize
+        is_lagging = leader_optime and leader_optime > replayed_location + max_replica_lag
 
-        replica_status_code = 200 if not patroni.noloadbalance and \
+        replica_status_code = 200 if not patroni.noloadbalance and not is_lagging and \
             response.get('role') == 'replica' and response.get('state') == 'running' else 503
+
+        if not cluster and patroni.ha.is_paused():
+            leader_status_code = 200 if response.get('role') in ('master', 'standby_leader') else 503
+            primary_status_code = 200 if response.get('role') == 'master' else 503
+            standby_leader_status_code = 200 if response.get('role') == 'standby_leader' else 503
+        elif patroni.ha.is_leader():
+            leader_status_code = 200
+            if patroni.ha.is_standby_cluster():
+                primary_status_code = replica_status_code = 503
+                standby_leader_status_code = 200 if response.get('role') in ('replica', 'standby_leader') else 503
+            else:
+                primary_status_code = 200
+                standby_leader_status_code = 503
+        else:
+            leader_status_code = primary_status_code = standby_leader_status_code = 503
+
         status_code = 503
 
-        if patroni.ha.is_standby_cluster() and ('standby_leader' in path or 'standby-leader' in path):
-            status_code = 200 if patroni.ha.is_leader() else 503
-        elif 'master' in path or 'leader' in path or 'primary' in path or 'read-write' in path:
+        ignore_tags = False
+        if 'standby_leader' in path or 'standby-leader' in path:
+            status_code = standby_leader_status_code
+            ignore_tags = True
+        elif 'leader' in path:
+            status_code = leader_status_code
+            ignore_tags = True
+        elif 'master' in path or 'primary' in path or 'read-write' in path:
             status_code = primary_status_code
+            ignore_tags = True
         elif 'replica' in path:
             status_code = replica_status_code
         elif 'read-only' in path:
-            status_code = 200 if primary_status_code == 200 else replica_status_code
+            status_code = 200 if 200 in (primary_status_code, standby_leader_status_code) else replica_status_code
         elif 'health' in path:
             status_code = 200 if response.get('state') == 'running' else 503
         elif cluster:  # dcs is available
             is_synchronous = cluster.is_synchronous_mode() and cluster.sync \
-                    and cluster.sync.sync_standby == patroni.postgresql.name
+                    and patroni.postgresql.name in cluster.sync.members
             if path in ('/sync', '/synchronous') and is_synchronous:
                 status_code = replica_status_code
             elif path in ('/async', '/asynchronous') and not is_synchronous:
                 status_code = replica_status_code
 
+        # check for user defined tags in query params
+        if not ignore_tags and status_code == 200:
+            qs_tag_prefix = "tag_"
+            for qs_key, qs_value in self.path_query.items():
+                if not qs_key.startswith(qs_tag_prefix):
+                    continue
+                qs_key = qs_key[len(qs_tag_prefix):]
+                qs_value = qs_value[0]
+                instance_tag_value = patroni.tags.get(qs_key)
+                # tag not registered for instance
+                if instance_tag_value is None:
+                    status_code = 503
+                    break
+                if not isinstance(instance_tag_value, six.string_types):
+                    instance_tag_value = str(instance_tag_value).lower()
+                if instance_tag_value != qs_value:
+                    status_code = 503
+                    break
+
         if write_status_code_only:  # when haproxy sends OPTIONS request it reads only status code and nothing more
-            message = self.responses[status_code][0]
-            self.wfile.write('{0} {1} {2}\r\n'.format(self.protocol_version, status_code, message).encode('utf-8'))
+            self._write_status_code_only(status_code)
         else:
             self._write_status_response(status_code, response)
 
-        time_end = time.time()
-        self.log_message('%s %s %s latency: %s ms', request_type, path,
-                         status_code, (time_end - time_start) * 1000)
-
     def do_OPTIONS(self):
         self.do_GET(write_status_code_only=True)
 
+    def do_GET_liveness(self):
+        self._write_status_code_only(200)
+
+    def do_GET_readiness(self):
+        patroni = self.server.patroni
+        if patroni.ha.is_leader():
+            status_code = 200
+        elif patroni.postgresql.state == 'running':
+            status_code = 200 if patroni.dcs.cluster else 503
+        else:
+            status_code = 503
+        self._write_status_code_only(status_code)
+
     def do_GET_patroni(self):
         response = self.get_postgresql_status(True)
         self._write_status_response(200, response)
 
     def do_GET_cluster(self):
-        cluster = self.server.patroni.dcs.cluster or self.server.patroni.dcs.get_cluster()
+        cluster = self.server.patroni.dcs.get_cluster(True)
         self._write_json_response(200, cluster_as_json(cluster))
 
     def do_GET_history(self):
@@ -148,6 +212,89 @@ class RestApiHandler(BaseHTTPRequestHandler):
         else:
             self.send_error(502)
 
+    def do_GET_metrics(self):
+        postgres = self.get_postgresql_status(True)
+        patroni = self.server.patroni
+        epoch = datetime.datetime(1970, 1, 1, tzinfo=tzutc)
+
+        metrics = []
+
+        scope_label = '{{scope="{0}"}}'.format(patroni.postgresql.scope)
+        metrics.append("# HELP patroni_version Patroni semver without periods.")
+        metrics.append("# TYPE patroni_version gauge")
+        padded_semver = ''.join([x.zfill(2) for x in patroni.version.split('.')])  # 2.0.2 => 020002
+        metrics.append("patroni_version{0} {1}".format(scope_label, padded_semver))
+
+        metrics.append("# HELP patroni_postgres_running Value is 1 if Postgres is running, 0 otherwise.")
+        metrics.append("# TYPE patroni_postgres_running gauge")
+        metrics.append("patroni_postgres_running{0} {1}".format(scope_label, int(postgres['state'] == 'running')))
+
+        metrics.append("# HELP patroni_postmaster_start_time Epoch seconds since Postgres started.")
+        metrics.append("# TYPE patroni_postmaster_start_time gauge")
+        postmaster_start_time = postgres.get('postmaster_start_time')
+        postmaster_start_time = (postmaster_start_time - epoch).total_seconds() if postmaster_start_time else 0
+        metrics.append("patroni_postmaster_start_time{0} {1}".format(scope_label, postmaster_start_time))
+
+        metrics.append("# HELP patroni_master Value is 1 if this node is the leader, 0 otherwise.")
+        metrics.append("# TYPE patroni_master gauge")
+        metrics.append("patroni_master{0} {1}".format(scope_label, int(postgres['role'] == 'master')))
+
+        metrics.append("# HELP patroni_xlog_location Current location of the Postgres"
+                       " transaction log, 0 if this node is not the leader.")
+        metrics.append("# TYPE patroni_xlog_location counter")
+        metrics.append("patroni_xlog_location{0} {1}".format(scope_label, postgres.get('xlog', {}).get('location', 0)))
+
+        metrics.append("# HELP patroni_standby_leader Value is 1 if this node is the standby_leader, 0 otherwise.")
+        metrics.append("# TYPE patroni_standby_leader gauge")
+        metrics.append("patroni_standby_leader{0} {1}".format(scope_label, int(postgres['role'] == 'standby_leader')))
+
+        metrics.append("# HELP patroni_replica Value is 1 if this node is a replica, 0 otherwise.")
+        metrics.append("# TYPE patroni_replica gauge")
+        metrics.append("patroni_replica{0} {1}".format(scope_label, int(postgres['role'] == 'replica')))
+
+        metrics.append("# HELP patroni_xlog_received_location Current location of the received"
+                       " Postgres transaction log, 0 if this node is not a replica.")
+        metrics.append("# TYPE patroni_xlog_received_location counter")
+        metrics.append("patroni_xlog_received_location{0} {1}"
+                       .format(scope_label, postgres.get('xlog', {}).get('received_location', 0)))
+
+        metrics.append("# HELP patroni_xlog_replayed_location Current location of the replayed"
+                       " Postgres transaction log, 0 if this node is not a replica.")
+        metrics.append("# TYPE patroni_xlog_replayed_location counter")
+        metrics.append("patroni_xlog_replayed_location{0} {1}"
+                       .format(scope_label, postgres.get('xlog', {}).get('replayed_location', 0)))
+
+        metrics.append("# HELP patroni_xlog_replayed_timestamp Current timestamp of the replayed"
+                       " Postgres transaction log, 0 if null.")
+        metrics.append("# TYPE patroni_xlog_replayed_timestamp gauge")
+        replayed_timestamp = postgres.get('xlog', {}).get('replayed_timestamp')
+        replayed_timestamp = (replayed_timestamp - epoch).total_seconds() if replayed_timestamp else 0
+        metrics.append("patroni_xlog_replayed_timestamp{0} {1}".format(scope_label, replayed_timestamp))
+
+        metrics.append("# HELP patroni_xlog_paused Value is 1 if the Postgres xlog is paused, 0 otherwise.")
+        metrics.append("# TYPE patroni_xlog_paused gauge")
+        metrics.append("patroni_xlog_paused{0} {1}"
+                       .format(scope_label, int(postgres.get('xlog', {}).get('paused', False) is True)))
+
+        metrics.append("# HELP patroni_postgres_server_version Version of Postgres (if running), 0 otherwise.")
+        metrics.append("# TYPE patroni_postgres_server_version gauge")
+        metrics.append("patroni_postgres_server_version {0} {1}".format(scope_label, postgres.get('server_version', 0)))
+
+        metrics.append("# HELP patroni_cluster_unlocked Value is 1 if the cluster is unlocked, 0 if locked.")
+        metrics.append("# TYPE patroni_cluster_unlocked gauge")
+        metrics.append("patroni_cluster_unlocked{0} {1}".format(scope_label, int(postgres.get('cluster_unlocked', 0))))
+
+        metrics.append("# HELP patroni_postgres_timeline Postgres timeline of this node (if running), 0 otherwise.")
+        metrics.append("# TYPE patroni_postgres_timeline counter")
+        metrics.append("patroni_postgres_timeline{0} {1}".format(scope_label, postgres.get('timeline', 0)))
+
+        metrics.append("# HELP patroni_dcs_last_seen Epoch timestamp when DCS was last contacted successfully"
+                       " by Patroni.")
+        metrics.append("# TYPE patroni_dcs_last_seen gauge")
+        metrics.append("patroni_dcs_last_seen{0} {1}".format(scope_label, postgres.get('dcs_last_seen', 0)))
+
+        self._write_response(200, '\n'.join(metrics)+'\n', content_type='text/plain')
+
     def _read_json_content(self, body_is_optional=False):
         if 'content-length' not in self.headers:
             return self.send_error(411) if not body_is_optional else {}
@@ -162,11 +309,13 @@ class RestApiHandler(BaseHTTPRequestHandler):
             logger.exception('Bad request')
         self.send_error(400)
 
-    @check_auth
+    @check_access
     def do_PATCH_config(self):
         request = self._read_json_content()
         if request:
-            cluster = self.server.patroni.dcs.get_cluster()
+            cluster = self.server.patroni.dcs.get_cluster(True)
+            if not (cluster.config and cluster.config.modify_index):
+                return self.send_error(503)
             data = cluster.config.data.copy()
             if patch_config(data, request):
                 value = json.dumps(data, separators=(',', ':'))
@@ -175,7 +324,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
             self.server.patroni.ha.wakeup()
             self._write_json_response(200, data)
 
-    @check_auth
+    @check_access
     def do_PUT_config(self):
         request = self._read_json_content()
         if request:
@@ -186,7 +335,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
                     return self.send_error(502)
             self._write_json_response(200, request)
 
-    @check_auth
+    @check_access
     def do_POST_reload(self):
         self.server.patroni.sighup_handler()
         self._write_response(202, 'reload scheduled')
@@ -212,7 +361,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
             status_code = 422
         return (status_code, error, scheduled_at)
 
-    @check_auth
+    @check_access
     def do_POST_restart(self):
         status_code = 500
         data = 'restart failed'
@@ -273,7 +422,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
                     status_code = 409
         self._write_response(status_code, data)
 
-    @check_auth
+    @check_access
     def do_DELETE_restart(self):
         if self.server.patroni.ha.delete_future_restart():
             data = "scheduled restart deleted"
@@ -283,7 +432,21 @@ class RestApiHandler(BaseHTTPRequestHandler):
             code = 404
         self._write_response(code, data)
 
-    @check_auth
+    @check_access
+    def do_DELETE_switchover(self):
+        failover = self.server.patroni.dcs.get_cluster().failover
+        if failover and failover.scheduled_at:
+            if not self.server.patroni.dcs.manual_failover('', '', index=failover.index):
+                return self.send_error(409)
+            else:
+                data = "scheduled switchover deleted"
+                code = 200
+        else:
+            data = "no switchover is scheduled"
+            code = 404
+        self._write_response(code, data)
+
+    @check_access
     def do_POST_reinitialize(self):
         request = self._read_json_content(body_is_optional=True)
 
@@ -315,20 +478,20 @@ class RestApiHandler(BaseHTTPRequestHandler):
                 if not cluster.failover:
                     return 503, action.title() + ' failed'
             except Exception as e:
-                logger.debug('Exception occured during polling %s result: %s', action, e)
+                logger.debug('Exception occurred during polling %s result: %s', action, e)
         return 503, action.title() + ' status unknown'
 
     def is_failover_possible(self, cluster, leader, candidate, action):
         if leader and (not cluster.leader or cluster.leader.name != leader):
             return 'leader name does not match'
         if candidate:
-            if action == 'switchover' and cluster.is_synchronous_mode() and cluster.sync.sync_standby != candidate:
+            if action == 'switchover' and cluster.is_synchronous_mode() and candidate not in cluster.sync.members:
                 return 'candidate name does not match with sync_standby'
             members = [m for m in cluster.members if m.name == candidate]
             if not members:
                 return 'candidate does not exists'
         elif cluster.is_synchronous_mode():
-            members = [m for m in cluster.members if m.name == cluster.sync.sync_standby]
+            members = [m for m in cluster.members if m.name in cluster.sync.members]
             if not members:
                 return action + ' is not possible: can not find sync_standby'
         else:
@@ -340,7 +503,7 @@ class RestApiHandler(BaseHTTPRequestHandler):
                 return None
         return action + ' is not possible: no good candidates have been found'
 
-    @check_auth
+    @check_access
     def do_POST_failover(self, action='failover'):
         request = self._read_json_content()
         (status_code, data) = (400, '')
@@ -405,6 +568,9 @@ class RestApiHandler(BaseHTTPRequestHandler):
 
         ret = BaseHTTPRequestHandler.parse_request(self)
         if ret:
+            urlpath = urlparse(self.path)
+            self.path = urlpath.path
+            self.path_query = parse_qs(urlpath.query) or {}
             mname = self.path.lstrip('/').split('/')[0]
             mname = self.command + ('_' + mname if mname else '')
             if hasattr(self, 'do_' + mname):
@@ -418,67 +584,66 @@ class RestApiHandler(BaseHTTPRequestHandler):
         return retry(self.server.query, sql, *params)
 
     def get_postgresql_status(self, retry=False):
+        postgresql = self.server.patroni.postgresql
         try:
             cluster = self.server.patroni.dcs.cluster
 
-            if self.server.patroni.postgresql.state not in ('running', 'restarting', 'starting'):
+            if postgresql.state not in ('running', 'restarting', 'starting'):
                 raise RetryFailedError('')
-            stmt = ("SELECT pg_catalog.to_char(pg_catalog.pg_postmaster_start_time(), 'YYYY-MM-DD HH24:MI:SS.MS TZ'),"
-                    " CASE WHEN pg_catalog.pg_is_in_recovery() THEN 0"
-                    " ELSE ('x' || pg_catalog.substr(pg_catalog.pg_{0}file_name("
-                    "pg_catalog.pg_current_{0}_{1}()), 1, 8))::bit(32)::int END,"
-                    " CASE WHEN pg_catalog.pg_is_in_recovery() THEN 0"
-                    " ELSE pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_current_{0}_{1}(), '0/0')::bigint END,"
-                    " pg_catalog.pg_{0}_{1}_diff(COALESCE(pg_catalog.pg_last_{0}_receive_{1}(),"
-                    " pg_catalog.pg_last_{0}_replay_{1}()), '0/0')::bigint,"
-                    " pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_last_{0}_replay_{1}(), '0/0')::bigint,"
-                    " pg_catalog.to_char(pg_catalog.pg_last_xact_replay_timestamp(), 'YYYY-MM-DD HH24:MI:SS.MS TZ'),"
-                    " pg_catalog.pg_is_in_recovery() AND pg_catalog.pg_is_{0}_replay_paused(), "
+            stmt = ("SELECT " + postgresql.POSTMASTER_START_TIME + ", " + postgresql.TL_LSN + ","
+                    " pg_catalog.pg_last_xact_replay_timestamp(),"
                     " pg_catalog.array_to_json(pg_catalog.array_agg(pg_catalog.row_to_json(ri))) "
                     "FROM (SELECT (SELECT rolname FROM pg_authid WHERE oid = usesysid) AS usename,"
                     " application_name, client_addr, w.state, sync_state, sync_priority"
                     " FROM pg_catalog.pg_stat_get_wal_senders() w, pg_catalog.pg_stat_get_activity(pid)) AS ri")
 
-            row = self.query(stmt.format(self.server.patroni.postgresql.wal_name,
-                                         self.server.patroni.postgresql.lsn_name), retry=retry)[0]
+            row = self.query(stmt.format(postgresql.wal_name, postgresql.lsn_name), retry=retry)[0]
 
             result = {
-                'state': self.server.patroni.postgresql.state,
+                'state': postgresql.state,
                 'postmaster_start_time': row[0],
                 'role': 'replica' if row[1] == 0 else 'master',
-                'server_version': self.server.patroni.postgresql.server_version,
-                'cluster_unlocked': bool(not cluster or cluster.is_unlocked()),
+                'server_version': postgresql.server_version,
                 'xlog': ({
-                    'received_location': row[3],
-                    'replayed_location': row[4],
-                    'replayed_timestamp': row[5],
-                    'paused': row[6]} if row[1] == 0 else {
+                    'received_location': row[4] or row[3],
+                    'replayed_location': row[3],
+                    'replayed_timestamp': row[6],
+                    'paused': row[5]} if row[1] == 0 else {
                     'location': row[2]
                 })
             }
 
             if result['role'] == 'replica' and self.server.patroni.ha.is_standby_cluster():
-                result['role'] = self.server.patroni.postgresql.role
+                result['role'] = postgresql.role
 
             if row[1] > 0:
                 result['timeline'] = row[1]
             else:
                 leader_timeline = None if not cluster or cluster.is_unlocked() else cluster.leader.timeline
-                result['timeline'] = self.server.patroni.postgresql.replica_cached_timeline(leader_timeline)
+                result['timeline'] = postgresql.replica_cached_timeline(leader_timeline)
 
             if row[7]:
                 result['replication'] = row[7]
 
-            return result
-        except (psycopg2.Error, RetryFailedError, PostgresConnectionException):
-            state = self.server.patroni.postgresql.state
+        except (psycopg.Error, RetryFailedError, PostgresConnectionException):
+            state = postgresql.state
             if state == 'running':
                 logger.exception('get_postgresql_status')
                 state = 'unknown'
-            return {'state': state, 'role': self.server.patroni.postgresql.role}
+            result = {'state': state, 'role': postgresql.role}
+
+        if not cluster or cluster.is_unlocked():
+            result['cluster_unlocked'] = True
+        result['dcs_last_seen'] = self.server.patroni.dcs.last_seen
+        return result
+
+    def handle_one_request(self):
+        self.__start_time = time.time()
+        BaseHTTPRequestHandler.handle_one_request(self)
 
     def log_message(self, fmt, *args):
-        logger.debug("API thread: %s - - [%s] %s", self.client_address[0], self.log_date_time_string(), fmt % args)
+        latency = 1000.0 * (time.time() - self.__start_time)
+        logger.debug("API thread: %s - - %s latency: %0.3f ms", self.client_address[0], fmt % args, latency)
 
 
 class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
@@ -489,6 +654,8 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
         self.patroni = patroni
         self.__listen = None
         self.__ssl_options = None
+        self.__ssl_serial_number = None
+        self._received_new_cert = False
         self.reload_config(config)
         self.daemon = True
 
@@ -498,7 +665,7 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
             with self.patroni.postgresql.connection().cursor() as cursor:
                 cursor.execute(sql, params)
                 return [r for r in cursor]
-        except psycopg2.Error as e:
+        except psycopg.Error as e:
             if cursor and cursor.connection.closed == 0:
                 raise e
             raise PostgresConnectionException('connection problems')
@@ -511,7 +678,7 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
             fcntl.fcntl(fd, fcntl.F_SETFD, flags | fcntl.FD_CLOEXEC)
 
     def check_basic_auth_key(self, key):
-        return self.__auth_key == key
+        return hmac.compare_digest(self.__auth_key, key.encode('utf-8'))
 
     def check_auth_header(self, auth_header):
         if self.__auth_key:
@@ -520,15 +687,43 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
             if not auth_header.startswith('Basic ') or not self.check_basic_auth_key(auth_header[6:]):
                 return 'not authenticated'
 
-    def check_auth(self, rh):
+    @staticmethod
+    def __resolve_ips(host, port):
+        try:
+            for _, _, _, _, sa in socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM, socket.IPPROTO_TCP):
+                yield ip_network(sa[0])
+        except Exception as e:
+            logger.error('Failed to resolve %s: %r', host, e)
+
+    def __members_ips(self):
+        cluster = self.patroni.dcs.cluster
+        if self.__allowlist_include_members and cluster:
+            for member in cluster.members:
+                if member.api_url:
+                    try:
+                        r = urlparse(member.api_url)
+                        host = r.hostname
+                        port = r.port or (443 if r.scheme == 'https' else 80)
+                        for ip in self.__resolve_ips(host, port):
+                            yield ip
+                    except Exception as e:
+                        logger.debug('Failed to parse url %s: %r', member.api_url, e)
+
+    def check_access(self, rh):
+        if self.__allowlist or self.__allowlist_include_members:
+            incoming_ip = rh.client_address[0]
+            incoming_ip = ip_address(incoming_ip.decode('utf-8') if six.PY2 else incoming_ip)
+            if not any(incoming_ip in net for net in self.__allowlist + tuple(self.__members_ips())):
+                return rh._write_response(403, 'Access is denied')
+
         if not hasattr(rh.request, 'getpeercert') or not rh.request.getpeercert():  # valid client cert isn't present
             if self.__protocol == 'https' and self.__ssl_options.get('verify_client') in ('required', 'optional'):
                 return rh._write_response(403, 'client certificate required')
 
-            reason = self.check_auth_header(rh.headers.get('Authorization'))
-            if reason:
-                headers = {'WWW-Authenticate': 'Basic realm="' + self.patroni.__class__.__name__ + '"'}
-                return rh._write_response(401, reason, headers=headers)
+        reason = self.check_auth_header(rh.headers.get('Authorization'))
+        if reason:
+            headers = {'WWW-Authenticate': 'Basic realm="' + self.patroni.__class__.__name__ + '"'}
+            return rh._write_response(401, reason, headers=headers)
         return True
 
     @staticmethod
@@ -576,6 +771,7 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
 
         self.__listen = listen
         self.__ssl_options = ssl_options
+        self._received_new_cert = False  # reset to False after reload_config()
 
         self.__httpserver_init(host, port)
         Thread.__init__(self, target=self.serve_forever)
@@ -587,7 +783,10 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
         if self.__protocol == 'https':
             import ssl
             ctx = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH, cafile=ssl_options.get('cafile'))
-            ctx.load_cert_chain(certfile=ssl_options['certfile'], keyfile=ssl_options.get('keyfile'))
+            if ssl_options.get('ciphers'):
+                ctx.set_ciphers(ssl_options['ciphers'])
+            ctx.load_cert_chain(certfile=ssl_options['certfile'], keyfile=ssl_options.get('keyfile'),
+                                password=ssl_options.get('keyfile_password'))
             verify_client = ssl_options.get('verify_client')
             if verify_client:
                 modes = {'none': ssl.CERT_NONE, 'optional': ssl.CERT_OPTIONAL, 'required': ssl.CERT_REQUIRED}
@@ -595,27 +794,87 @@ class RestApiServer(ThreadingMixIn, HTTPServer, Thread):
                     ctx.verify_mode = modes[verify_client]
                 else:
                     logger.error('Bad value in the "restapi.verify_client": %s', verify_client)
+            self.__ssl_serial_number = self.get_certificate_serial_number()
             self.socket = ctx.wrap_socket(self.socket, server_side=True)
         if reloading_config:
             self.start()
 
+    def process_request_thread(self, request, client_address):
+        if isinstance(request, tuple):
+            sock, newsock = request
+            try:
+                request = sock.context.wrap_socket(newsock, do_handshake_on_connect=sock.do_handshake_on_connect,
+                                                   suppress_ragged_eofs=sock.suppress_ragged_eofs, server_side=True)
+            except socket.error:
+                return
+        super(RestApiServer, self).process_request_thread(request, client_address)
+
+    def get_request(self):
+        sock = self.socket
+        newsock, addr = socket.socket.accept(sock)
+        enable_keepalive(newsock, 10, 3)
+        if hasattr(sock, 'context'):  # SSLSocket, we want to do the deferred handshake from a thread
+            newsock = (sock, newsock)
+        return newsock, addr
+
+    def shutdown_request(self, request):
+        if isinstance(request, tuple):
+            _, request = request  # SSLSocket
+        return super(RestApiServer, self).shutdown_request(request)
+
+    def get_certificate_serial_number(self):
+        if self.__ssl_options.get('certfile'):
+            import ssl
+            try:
+                crt = ssl._ssl._test_decode_cert(self.__ssl_options['certfile'])
+                return crt.get('serialNumber')
+            except ssl.SSLError as e:
+                logger.error('Failed to get serial number from certificate %s: %r', self.__ssl_options['certfile'], e)
+
+    def reload_local_certificate(self):
+        if self.__protocol == 'https':
+            on_disk_cert_serial_number = self.get_certificate_serial_number()
+            if on_disk_cert_serial_number != self.__ssl_serial_number:
+                self._received_new_cert = True
+                self.__ssl_serial_number = on_disk_cert_serial_number
+                return True
+
+    def _build_allowlist(self, value):
+        if isinstance(value, list):
+            for v in value:
+                if '/' in v:  # netmask
+                    try:
+                        yield ip_network(v)
+                    except Exception as e:
+                        logger.error('Invalid value "%s" in the allowlist: %r', v, e)
+                else:  # ip or hostname, try to resolve it
+                    for ip in self.__resolve_ips(v, 8080):
+                        yield ip
+
     def reload_config(self, config):
         if 'listen' not in config:  # changing config in runtime
             raise ValueError('Can not find "restapi.listen" config')
 
-        ssl_options = {n: config[n] for n in ('certfile', 'keyfile', 'cafile') if n in config}
+        self.__allowlist = tuple(self._build_allowlist(config.get('allowlist')))
+        self.__allowlist_include_members = config.get('allowlist_include_members')
+
+        ssl_options = {n: config[n] for n in ('certfile', 'keyfile', 'keyfile_password',
+                                              'cafile', 'ciphers') if n in config}
+
+        self.http_extra_headers = config.get('http_extra_headers') or {}
+        self.http_extra_headers.update((config.get('https_extra_headers') or {}) if ssl_options.get('certfile') else {})
 
         if isinstance(config.get('verify_client'), six.string_types):
             ssl_options['verify_client'] = config['verify_client'].lower()
 
-        if self.__listen != config['listen'] or self.__ssl_options != ssl_options:
+        if self.__listen != config['listen'] or self.__ssl_options != ssl_options or self._received_new_cert:
             self.__initialize(config['listen'], ssl_options)
 
-        self.__auth_key = base64.b64encode(config['auth'].encode('utf-8')).decode('utf-8') if 'auth' in config else None
+        self.__auth_key = base64.b64encode(config['auth'].encode('utf-8')) if 'auth' in config else None
         self.connection_string = uri(self.__protocol, config.get('connect_address') or self.__listen, 'patroni')
 
     @staticmethod
     def handle_error(request, client_address):
-        address, port = client_address
-        logger.warning('Exception happened during processing of request from {}:{}'.format(address, port))
+        logger.warning('Exception happened during processing of request from %s:%s',
+                       client_address[0], client_address[1])
         logger.warning(traceback.format_exc())

patroni/config.py

@@ -21,8 +21,12 @@ _AUTH_ALLOWED_PARAMETERS = (
     'sslmode',
     'sslcert',
     'sslkey',
+    'sslpassword',
     'sslrootcert',
-    'sslcrl'
+    'sslcrl',
+    'sslcrldir',
+    'gssencmode',
+    'channel_binding'
 )
 
 
@@ -57,11 +61,13 @@ class Config(object):
     __DEFAULT_CONFIG = {
         'ttl': 30, 'loop_wait': 10, 'retry_timeout': 10,
         'maximum_lag_on_failover': 1048576,
+        'maximum_lag_on_syncnode': -1,
         'check_timeline': False,
         'master_start_timeout': 300,
         'master_stop_timeout': 0,
         'synchronous_mode': False,
         'synchronous_mode_strict': False,
+        'synchronous_node_count': 1,
         'standby_cluster': {
             'create_replica_methods': '',
             'host': '',
@@ -74,7 +80,8 @@ class Config(object):
         'postgresql': {
             'bin_dir': '',
             'use_slots': True,
-            'parameters': CaseInsensitiveDict({p: v[0] for p, v in ConfigHandler.CMDLINE_OPTIONS.items()})
+            'parameters': CaseInsensitiveDict({p: v[0] for p, v in ConfigHandler.CMDLINE_OPTIONS.items()
+                                               if p not in ('wal_keep_segments', 'wal_keep_size')})
         },
         'watchdog': {
             'mode': 'automatic',
@@ -88,7 +95,7 @@ class Config(object):
         self.__environment_configuration = self._build_environment_configuration()
 
         # Patroni reads the configuration from the command-line argument if it exists, otherwise from the environment
-        self._config_file = configfile and os.path.isfile(configfile) and configfile
+        self._config_file = configfile and os.path.exists(configfile) and configfile
         if self._config_file:
             self._local_configuration = self._load_config_file()
         else:
@@ -116,12 +123,32 @@ class Config(object):
     def check_mode(self, mode):
         return bool(parse_bool(self._dynamic_configuration.get(mode)))
 
+    def _load_config_path(self, path):
+        """
+        If path is a file, loads the yml file pointed to by path.
+        If path is a directory, loads all yml files in that directory in alphabetical order
+        """
+        if os.path.isfile(path):
+            files = [path]
+        elif os.path.isdir(path):
+            files = [os.path.join(path, f) for f in sorted(os.listdir(path))
+                     if (f.endswith('.yml') or f.endswith('.yaml')) and os.path.isfile(os.path.join(path, f))]
+        else:
+            logger.error('config path %s is neither directory nor file', path)
+            raise ConfigParseError('invalid config path')
+
+        overall_config = {}
+        for fname in files:
+            with open(fname) as f:
+                config = yaml.safe_load(f)
+                patch_config(overall_config, config)
+        return overall_config
+
     def _load_config_file(self):
         """Loads config.yaml from filesystem and applies some values which were set via ENV"""
-        with open(self._config_file) as f:
-            config = yaml.safe_load(f)
-            patch_config(config, self.__environment_configuration)
-            return config
+        config = self._load_config_path(self._config_file)
+        patch_config(config, self.__environment_configuration)
+        return config
 
     def _load_cache(self):
         if os.path.isfile(self._cache_file):
@@ -206,7 +233,7 @@ class Config(object):
                 for name, value in (value or {}).items():
                     if name in self.__DEFAULT_CONFIG['standby_cluster']:
                         config['standby_cluster'][name] = deepcopy(value)
-            elif name in config:  # only variables present in __DEFAULT_CONFIG allowed to be overriden from DCS
+            elif name in config:  # only variables present in __DEFAULT_CONFIG allowed to be overridden from DCS
                 if name in ('synchronous_mode', 'synchronous_mode_strict'):
                     config[name] = value
                 else:
@@ -240,11 +267,44 @@ class Config(object):
                 if value:
                     ret[section][param] = value
 
-        _set_section_values('restapi', ['listen', 'connect_address', 'certfile', 'keyfile', 'cafile', 'verify_client'])
+        _set_section_values('restapi', ['listen', 'connect_address', 'certfile', 'keyfile', 'keyfile_password',
+                                        'cafile', 'ciphers', 'verify_client', 'http_extra_headers',
+                                        'https_extra_headers', 'allowlist', 'allowlist_include_members'])
         _set_section_values('ctl', ['insecure', 'cacert', 'certfile', 'keyfile'])
         _set_section_values('postgresql', ['listen', 'connect_address', 'config_dir', 'data_dir', 'pgpass', 'bin_dir'])
         _set_section_values('log', ['level', 'traceback_level', 'format', 'dateformat', 'max_queue_size',
                                     'dir', 'file_size', 'file_num', 'loggers'])
+        _set_section_values('raft', ['data_dir', 'self_addr', 'partner_addrs', 'password', 'bind_addr'])
+
+        for first, second in (('restapi', 'allowlist_include_members'), ('ctl', 'insecure')):
+            value = ret.get(first, {}).pop(second, None)
+            if value:
+                value = parse_bool(value)
+                if value is not None:
+                    ret[first][second] = value
+
+        for second in ('max_queue_size', 'file_size', 'file_num'):
+            value = ret.get('log', {}).pop(second, None)
+            if value:
+                value = parse_int(value)
+                if value is not None:
+                    ret['log'][second] = value
+
+        def _parse_list(value):
+            if not (value.strip().startswith('-') or '[' in value):
+                value = '[{0}]'.format(value)
+            try:
+                return yaml.safe_load(value)
+            except Exception:
+                logger.exception('Exception when parsing list %s', value)
+                return None
+
+        for first, second in (('raft', 'partner_addrs'), ('restapi', 'allowlist')):
+            value = ret.get(first, {}).pop(second, None)
+            if value:
+                value = _parse_list(value)
+                if value:
+                    ret[first][second] = value
 
         def _parse_dict(value):
             if not value.strip().startswith('{'):
@@ -255,11 +315,13 @@ class Config(object):
                 logger.exception('Exception when parsing dict %s', value)
                 return None
 
-        value = ret.get('log', {}).pop('loggers', None)
-        if value:
-            value = _parse_dict(value)
-            if value:
-                ret['log']['loggers'] = value
+        for first, params in (('restapi', ('http_extra_headers', 'https_extra_headers')), ('log', ('loggers',))):
+            for second in params:
+                value = ret.get(first, {}).pop(second, None)
+                if value:
+                    value = _parse_dict(value)
+                    if value:
+                        ret[first][second] = value
 
         def _get_auth(name, params=None):
             ret = {}
@@ -282,36 +344,29 @@ class Config(object):
         if authentication:
             ret['postgresql']['authentication'] = authentication
 
-        def _parse_list(value):
-            if not (value.strip().startswith('-') or '[' in value):
-                value = '[{0}]'.format(value)
-            try:
-                return yaml.safe_load(value)
-            except Exception:
-                logger.exception('Exception when parsing list %s', value)
-                return None
-
         for param in list(os.environ.keys()):
             if param.startswith(PATRONI_ENV_PREFIX):
                 # PATRONI_(ETCD|CONSUL|ZOOKEEPER|EXHIBITOR|...)_(HOSTS?|PORT|..)
                 name, suffix = (param[8:].split('_', 1) + [''])[:2]
-                if suffix in ('HOST', 'HOSTS', 'PORT', 'USE_PROXIES', 'PROTOCOL', 'SRV', 'URL', 'PROXY',
+                if suffix in ('HOST', 'HOSTS', 'PORT', 'USE_PROXIES', 'PROTOCOL', 'SRV', 'SRV_SUFFIX', 'URL', 'PROXY',
                               'CACERT', 'CERT', 'KEY', 'VERIFY', 'TOKEN', 'CHECKS', 'DC', 'CONSISTENCY',
                               'REGISTER_SERVICE', 'SERVICE_CHECK_INTERVAL', 'NAMESPACE', 'CONTEXT',
-                              'USE_ENDPOINTS', 'SCOPE_LABEL', 'ROLE_LABEL', 'POD_IP', 'PORTS', 'LABELS') and name:
+                              'USE_ENDPOINTS', 'SCOPE_LABEL', 'ROLE_LABEL', 'POD_IP', 'PORTS', 'LABELS',
+                              'BYPASS_API_SERVICE', 'KEY_PASSWORD', 'USE_SSL', 'SET_ACLS') and name:
                     value = os.environ.pop(param)
                     if suffix == 'PORT':
                         value = value and parse_int(value)
                     elif suffix in ('HOSTS', 'PORTS', 'CHECKS'):
                         value = value and _parse_list(value)
-                    elif suffix == 'LABELS':
+                    elif suffix in ('LABELS', 'SET_ACLS'):
                         value = _parse_dict(value)
-                    elif suffix in ('USE_PROXIES', 'REGISTER_SERVICE'):
+                    elif suffix in ('USE_PROXIES', 'REGISTER_SERVICE', 'USE_ENDPOINTS', 'BYPASS_API_SERVICE', 'VERIFY'):
                         value = parse_bool(value)
                     if value:
                         ret[name.lower()][suffix.lower()] = value
-        if 'etcd' in ret:
-            ret['etcd'].update(_get_auth('etcd'))
+        for dcs in ('etcd', 'etcd3'):
+            if dcs in ret:
+                ret[dcs].update(_get_auth(dcs))
 
         users = {}
         for param in list(os.environ.keys()):
@@ -379,6 +434,8 @@ class Config(object):
             'retry_timeout',
             'synchronous_mode',
             'synchronous_mode_strict',
+            'synchronous_node_count',
+            'maximum_lag_on_syncnode'
         )
 
         pg_config.update({p: config[p] for p in updated_fields if p in config})

patroni/ctl.py

@@ -7,7 +7,6 @@ import codecs
 import datetime
 import dateutil.parser
 import dateutil.tz
-import cdiff
 import copy
 import difflib
 import io
@@ -23,17 +22,24 @@ import time
 import yaml
 
 from click import ClickException
+from collections import defaultdict
 from contextlib import contextmanager
-from patroni.dcs import get_dcs as _get_dcs
-from patroni.exceptions import PatroniException
-from patroni.postgresql import Postgresql
-from patroni.postgresql.misc import postgres_version_to_int
-from patroni.utils import cluster_as_json, patch_config, polling_loop
-from patroni.request import PatroniRequest
-from patroni.version import __version__
 from prettytable import ALL, FRAME, PrettyTable
 from six.moves.urllib_parse import urlparse
 
+try:
+    from ydiff import markup_to_pager, PatchStream
+except ImportError:  # pragma: no cover
+    from cdiff import markup_to_pager, PatchStream
+
+from .dcs import get_dcs as _get_dcs
+from .exceptions import PatroniException
+from .postgresql import Postgresql
+from .postgresql.misc import postgres_version_to_int
+from .utils import cluster_as_json, find_executable, patch_config, polling_loop
+from .request import PatroniRequest
+from .version import __version__
+
 CONFIG_DIR_PATH = click.get_app_dir('patroni')
 CONFIG_FILE_PATH = os.path.join(CONFIG_DIR_PATH, 'patronictl.yaml')
 DCS_DEFAULTS = {'zookeeper': {'port': 2181, 'template': "zookeeper:\n hosts: ['{host}:{port}']"},
@@ -170,14 +176,14 @@ def print_output(columns, rows, alignment=None, fmt='pretty', header=None, delim
         elements = [{k: v for k, v in zip(columns, r) if not header or str(v)} for r in rows]
         func = json.dumps if fmt == 'json' else format_config_for_editing
         click.echo(func(elements))
-    elif fmt in {'pretty', 'tsv'}:
+    elif fmt in {'pretty', 'tsv', 'topology'}:
         list_cluster = bool(header and columns and columns[0] == 'Cluster')
         if list_cluster and 'Tags' in columns:  # we want to format member tags as YAML
             i = columns.index('Tags')
             for row in rows:
                 if row[i]:
-                    row[i] = format_config_for_editing(row[i], fmt == 'tsv').strip()
-        if list_cluster and fmt == 'pretty':  # skip cluster name if pretty-printing
+                    row[i] = format_config_for_editing(row[i], fmt != 'pretty').strip()
+        if list_cluster and fmt != 'tsv':  # skip cluster name if pretty-printing
             columns = columns[1:] if columns else []
             rows = [row[1:] for row in rows]
 
@@ -187,6 +193,7 @@ def print_output(columns, rows, alignment=None, fmt='pretty', header=None, delim
         else:
             hrules = ALL if any(any(isinstance(c, six.string_types) and '\n' in c for c in r) for r in rows) else FRAME
             table = PatronictlPrettyTable(header, columns, hrules=hrules)
+            table.align = 'l'
             for k, v in (alignment or {}).items():
                 table.align[k] = v
             for r in rows:
@@ -224,7 +231,7 @@ def watching(w, watch, max_count=None, clear=True):
 
 def get_all_members(cluster, role='master'):
     if role == 'master':
-        if cluster.leader is not None:
+        if cluster.leader is not None and cluster.leader.name:
             yield cluster.leader
         return
 
@@ -241,6 +248,15 @@ def get_any_member(cluster, role='master', member=None):
             return m
 
 
+def get_all_members_leader_first(cluster):
+    leader_name = cluster.leader.member.name if cluster.leader and cluster.leader.member.api_url else None
+    if leader_name:
+        yield cluster.leader.member
+    for member in cluster.members:
+        if member.api_url and member.name != leader_name:
+            yield member
+
+
 def get_cursor(cluster, connect_parameters, role='master', member=None):
     member = get_any_member(cluster, role=role, member=member)
     if member is None:
@@ -248,13 +264,13 @@ def get_cursor(cluster, connect_parameters, role='master', member=None):
 
     params = member.conn_kwargs(connect_parameters)
     params.update({'fallback_application_name': 'Patroni ctl', 'connect_timeout': '5'})
-    if 'database' in connect_parameters:
-        params['database'] = connect_parameters['database']
+    if 'dbname' in connect_parameters:
+        params['dbname'] = connect_parameters['dbname']
     else:
-        params.pop('database')
+        params.pop('dbname')
 
-    import psycopg2
-    conn = psycopg2.connect(**params)
+    from . import psycopg
+    conn = psycopg.connect(**params)
     conn.autocommit = True
     cursor = conn.cursor()
     if role == 'any':
@@ -385,7 +401,7 @@ def query(
     if password:
         connect_parameters['password'] = click.prompt('Password', hide_input=True, type=str)
     if dbname:
-        connect_parameters['database'] = dbname
+        connect_parameters['dbname'] = dbname
 
     if p_file is not None:
         command = p_file.read()
@@ -402,7 +418,7 @@ def query(
 
 
 def query_member(cluster, cursor, member, role, command, connect_parameters):
-    import psycopg2
+    from . import psycopg
     try:
         if cursor is None:
             cursor = get_cursor(cluster, connect_parameters, role=role, member=member)
@@ -417,11 +433,11 @@ def query_member(cluster, cursor, member, role, command, connect_parameters):
 
         cursor.execute(command)
         return cursor.fetchall(), [d.name for d in cursor.description]
-    except (psycopg2.OperationalError, psycopg2.DatabaseError) as oe:
-        logging.debug(oe)
+    except psycopg.DatabaseError as de:
+        logging.debug(de)
         if cursor is not None and not cursor.connection.closed:
             cursor.connection.close()
-        message = oe.pgcode or oe.pgerror or str(oe)
+        message = de.diag.sqlstate or str(de)
         message = message.replace('\n', ' ')
         return [[timestamp(0), 'ERROR, SQLSTATE: {0}'.format(message)]], None
 
@@ -630,7 +646,7 @@ def _do_failover_or_switchover(obj, action, cluster_name, master, candidate, for
     dcs = get_dcs(obj, cluster_name)
     cluster = dcs.get_cluster()
 
-    if action == 'switchover' and cluster.leader is None:
+    if action == 'switchover' and (cluster.leader is None or not cluster.leader.name):
         raise PatroniCtlException('This cluster has no master')
 
     if master is None:
@@ -746,6 +762,33 @@ def switchover(obj, cluster_name, master, candidate, force, scheduled):
     _do_failover_or_switchover(obj, 'switchover', cluster_name, master, candidate, force, scheduled)
 
 
+def generate_topology(level, member, topology):
+    members = topology.get(member['name'], [])
+
+    if level > 0:
+        member['name'] = '{0}+ {1}'.format((' ' * (level - 1) * 2), member['name'])
+
+    if member['name']:
+        yield member
+
+    for member in members:
+        for member in generate_topology(level + 1, member, topology):
+            yield member
+
+
+def topology_sort(members):
+    topology = defaultdict(list)
+    leader = next((m for m in members if m['role'].endswith('leader')), {'name': None})
+    replicas = set(member['name'] for member in members if not member['role'].endswith('leader'))
+    for member in members:
+        if not member['role'].endswith('leader'):
+            parent = member.get('tags', {}).get('replicatefrom')
+            parent = parent if parent and parent != member['name'] and parent in replicas else leader['name']
+            topology[parent].append(member)
+    for member in generate_topology(0, leader, topology):
+        yield member
+
+
 def output_members(cluster, name, extended=False, fmt='pretty'):
     rows = []
     logging.debug(cluster)
@@ -760,14 +803,15 @@ def output_members(cluster, name, extended=False, fmt='pretty'):
     # Show Host as 'host:port' if somebody is running on non-standard port or two nodes are running on the same host
     members = [m for m in cluster['members'] if 'host' in m]
     append_port = any('port' in m and m['port'] != 5432 for m in members) or\
-        len(set(m['host'] for m in cluster['members'])) < len(members)
+        len(set(m['host'] for m in members)) < len(members)
 
-    for m in cluster['members']:
+    sort = topology_sort if fmt == 'topology' else iter
+    for m in sort(cluster['members']):
         logging.debug(m)
 
         lag = m.get('lag', '')
-        m.update(cluster=name, member=m['name'], host=m.get('host'), tl=m.get('timeline', ''),
-                 role='' if m['role'] == 'replica' else m['role'].replace('_', ' ').title(),
+        m.update(cluster=name, member=m['name'], host=m.get('host', ''), tl=m.get('timeline', ''),
+                 role=m['role'].replace('_', ' ').title(),
                  lag_in_mb=round(lag/1024/1024) if isinstance(lag, six.integer_types) else lag,
                  pending_restart='*' if m.get('pending_restart') else '')
 
@@ -782,10 +826,9 @@ def output_members(cluster, name, extended=False, fmt='pretty'):
 
         rows.append([m.get(n.lower().replace(' ', '_'), '') for n in columns])
 
-    print_output(columns, rows, {'Lag in MB': 'r', 'TL': 'r', 'Tags': 'l'},
-                 fmt, ' Cluster: {0} ({1}) '.format(name, initialize))
+    print_output(columns, rows, {'Lag in MB': 'r', 'TL': 'r'}, fmt, ' Cluster: {0} ({1}) '.format(name, initialize))
 
-    if fmt != 'pretty':  # Omit service info when using machine-readable formats
+    if fmt not in ('pretty', 'topology'):  # Omit service info when using machine-readable formats
         return
 
     service_info = []
@@ -829,6 +872,16 @@ def members(obj, cluster_names, fmt, watch, w, extended, ts):
             output_members(cluster, cluster_name, extended, fmt)
 
 
+@ctl.command('topology', help='Prints ASCII topology for given cluster')
+@click.argument('cluster_names', nargs=-1)
+@option_watch
+@option_watchrefresh
+@click.pass_obj
+@click.pass_context
+def topology(ctx, obj, cluster_names, watch, w):
+    ctx.forward(members, fmt='topology')
+
+
 def timestamp(precision=6):
     return datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S.%f')[:precision - 7]
 
@@ -896,25 +949,45 @@ def scaffold(obj, cluster_name, sysid):
     click.echo("Cluster {0} has been created successfully".format(cluster_name))
 
 
-@ctl.command('flush', help='Discard scheduled events (restarts only currently)')
+@ctl.command('flush', help='Discard scheduled events')
 @click.argument('cluster_name')
 @click.argument('member_names', nargs=-1)
-@click.argument('target', type=click.Choice(['restart']))
+@click.argument('target', type=click.Choice(['restart', 'switchover']))
 @click.option('--role', '-r', help='Flush only members with this role', default='any',
               type=click.Choice(['master', 'replica', 'any']))
 @option_force
 @click.pass_obj
 def flush(obj, cluster_name, member_names, force, role, target):
-    cluster = get_dcs(obj, cluster_name).get_cluster()
+    dcs = get_dcs(obj, cluster_name)
+    cluster = dcs.get_cluster()
 
-    members = get_members(cluster, cluster_name, member_names, role, force, 'flush')
-    for member in members:
-        if target == 'restart':
+    if target == 'restart':
+        for member in get_members(cluster, cluster_name, member_names, role, force, 'flush'):
             if member.data.get('scheduled_restart'):
                 r = request_patroni(member, 'delete', 'restart')
                 check_response(r, member.name, 'flush scheduled restart')
             else:
                 click.echo('No scheduled restart for member {0}'.format(member.name))
+    elif target == 'switchover':
+        failover = cluster.failover
+        if not failover or not failover.scheduled_at:
+            return click.echo('No pending scheduled switchover')
+        for member in get_all_members_leader_first(cluster):
+            try:
+                r = request_patroni(member, 'delete', 'switchover')
+                if r.status in (200, 404):
+                    prefix = 'Success' if r.status == 200 else 'Failed'
+                    return click.echo('{0}: {1}'.format(prefix, r.data.decode('utf-8')))
+            except Exception as err:
+                logging.warning(str(err))
+                logging.warning('Member %s is not accessible', member.name)
+
+            click.echo('Failed: member={0}, status_code={1}, ({2})'.format(
+                member.name, r.status, r.data.decode('utf-8')))
+
+        logging.warning('Failing over to DCS')
+        click.echo('{0} Could not find any accessible member of cluster {1}'.format(timestamp(), cluster_name))
+        dcs.manual_failover('', '', index=failover.index)
 
 
 def wait_until_pause_is_applied(dcs, paused, old_cluster):
@@ -941,12 +1014,7 @@ def toggle_pause(config, cluster_name, paused, wait):
     if cluster.is_paused() == paused:
         raise PatroniCtlException('Cluster is {0} paused'.format(paused and 'already' or 'not'))
 
-    members = []
-    if cluster.leader:
-        members.append(cluster.leader.member)
-    members.extend([m for m in cluster.members if m.api_url and (not members or members[0].name != m.name)])
-
-    for member in members:
+    for member in get_all_members_leader_first(cluster):
         try:
             r = request_patroni(member, 'patch', 'config', {'pause': paused or None})
         except Exception as err:
@@ -1008,7 +1076,7 @@ def show_diff(before_editing, after_editing):
     If the output is to a tty the diff will be colored. Inputs are expected to be unicode strings.
     """
     def listify(string):
-        return [l+'\n' for l in string.rstrip('\n').split('\n')]
+        return [line + '\n' for line in string.rstrip('\n').split('\n')]
 
     unified_diff = difflib.unified_diff(listify(before_editing), listify(after_editing))
 
@@ -1023,7 +1091,14 @@ def show_diff(before_editing, after_editing):
             side_by_side = False
             width = 80
             tab_width = 8
-        cdiff.markup_to_pager(cdiff.PatchStream(buf), opts)
+            wrap = True
+            if find_executable('less'):
+                pager = None
+            else:
+                pager = 'more.com' if sys.platform == 'win32' else 'more'
+            pager_options = None
+
+        markup_to_pager(PatchStream(buf), opts)
     else:
         for line in unified_diff:
             click.echo(line.rstrip('\n'))
@@ -1098,24 +1173,6 @@ def apply_yaml_file(data, filename):
     return format_config_for_editing(changed_data), changed_data
 
 
-def find_executable(executable, path=None):
-    _, ext = os.path.splitext(executable)
-
-    if (sys.platform == 'win32') and (ext != '.exe'):
-        executable = executable + '.exe'
-
-    if os.path.isfile(executable):
-        return executable
-
-    if path is None:
-        path = os.environ.get('PATH', os.defpath)
-
-    for p in path.split(os.pathsep):
-        f = os.path.join(p, executable)
-        if os.path.isfile(f):
-            return f
-
-
 def invoke_editor(before_editing, cluster_name):
     """Starts editor command to edit configuration in human readable format
 
@@ -1242,10 +1299,13 @@ def version(obj, cluster_name, member_names):
 def history(obj, cluster_name, fmt):
     cluster = get_dcs(obj, cluster_name).get_cluster()
     history = cluster.history and cluster.history.lines or []
+    table_header_row = ['TL', 'LSN', 'Reason', 'Timestamp', 'New Leader']
     for line in history:
-        if len(line) < 4:
-            line.append('')
-    print_output(['TL', 'LSN', 'Reason', 'Timestamp'], history, {'TL': 'r', 'LSN': 'r'}, fmt)
+        if len(line) < len(table_header_row):
+            add_column_num = len(table_header_row) - len(line)
+            for _ in range(add_column_num):
+                line.append('')
+    print_output(table_header_row, history, {'TL': 'r', 'LSN': 'r'}, fmt)
 
 
 def format_pg_version(version):

patroni/daemon.py

@@ -0,0 +1,104 @@
+import abc
+import os
+import signal
+import six
+import sys
+
+from threading import Lock
+
+
+@six.add_metaclass(abc.ABCMeta)
+class AbstractPatroniDaemon(object):
+
+    def __init__(self, config):
+        from patroni.log import PatroniLogger
+
+        self.setup_signal_handlers()
+
+        self.logger = PatroniLogger()
+        self.config = config
+        AbstractPatroniDaemon.reload_config(self, local=True)
+
+    def sighup_handler(self, *args):
+        self._received_sighup = True
+
+    def sigterm_handler(self, *args):
+        with self._sigterm_lock:
+            if not self._received_sigterm:
+                self._received_sigterm = True
+                sys.exit()
+
+    def setup_signal_handlers(self):
+        self._received_sighup = False
+        self._sigterm_lock = Lock()
+        self._received_sigterm = False
+        if os.name != 'nt':
+            signal.signal(signal.SIGHUP, self.sighup_handler)
+        signal.signal(signal.SIGTERM, self.sigterm_handler)
+
+    @property
+    def received_sigterm(self):
+        with self._sigterm_lock:
+            return self._received_sigterm
+
+    def reload_config(self, sighup=False, local=False):
+        if local:
+            self.logger.reload_config(self.config.get('log', {}))
+
+    @abc.abstractmethod
+    def _run_cycle(self):
+        """_run_cycle"""
+
+    def run(self):
+        self.logger.start()
+        while not self.received_sigterm:
+            if self._received_sighup:
+                self._received_sighup = False
+                self.reload_config(True, self.config.reload_local_configuration())
+
+            self._run_cycle()
+
+    @abc.abstractmethod
+    def _shutdown(self):
+        """_shutdown"""
+
+    def shutdown(self):
+        with self._sigterm_lock:
+            self._received_sigterm = True
+        self._shutdown()
+        self.logger.shutdown()
+
+
+def abstract_main(cls, validator=None):
+    import argparse
+
+    from .config import Config, ConfigParseError
+    from .version import __version__
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--version', action='version', version='%(prog)s {0}'.format(__version__))
+    if validator:
+        parser.add_argument('--validate-config', action='store_true', help='Run config validator and exit')
+    parser.add_argument('configfile', nargs='?', default='',
+                        help='Patroni may also read the configuration from the {0} environment variable'
+                        .format(Config.PATRONI_CONFIG_VARIABLE))
+    args = parser.parse_args()
+    try:
+        if validator and args.validate_config:
+            Config(args.configfile, validator=validator)
+            sys.exit()
+
+        config = Config(args.configfile)
+    except ConfigParseError as e:
+        if e.value:
+            print(e.value)
+        parser.print_help()
+        sys.exit(1)
+
+    controller = cls(config)
+    try:
+        controller.run()
+    except KeyboardInterrupt:
+        pass
+    finally:
+        controller.shutdown()

patroni/dcs/__init__.py

@@ -13,12 +13,13 @@ import time
 
 from collections import defaultdict, namedtuple
 from copy import deepcopy
-from patroni.exceptions import PatroniException
-from patroni.utils import parse_bool, uri
 from random import randint
 from six.moves.urllib_parse import urlparse, urlunparse, parse_qsl
 from threading import Event, Lock
 
+from ..exceptions import PatroniFatalException
+from ..utils import deep_compare, parse_bool, uri
+
 slot_name_re = re.compile('^[a-z0-9_]{1,63}$')
 logger = logging.getLogger(__name__)
 
@@ -67,7 +68,11 @@ def dcs_modules():
 
     if getattr(sys, 'frozen', False):
         toc = set()
-        for importer in pkgutil.iter_importers(dcs_dirname):
+        # dcs_dirname may contain a dot, which causes pkgutil.iter_importers()
+        # to misinterpret the path as a package name. This can be avoided
+        # altogether by not passing a path at all, because PyInstaller's
+        # FrozenImporter is a singleton and registered as top-level finder.
+        for importer in pkgutil.iter_importers():
             if hasattr(importer, 'toc'):
                 toc |= importer.toc
         return [module for module in toc if module.startswith(module_prefix) and module.count('.') == 2]
@@ -102,7 +107,7 @@ def get_dcs(config):
                                              and inspect.isclass(item) and issubclass(item, AbstractDCS))
         except ImportError:
             logger.info('Failed to import %s', module_name)
-    raise PatroniException("""Can not find suitable configuration of distributed configuration store
+    raise PatroniFatalException("""Can not find suitable configuration of distributed configuration store
 Available implementations: """ + ', '.join(sorted(set(available_implementations))))
 
 
@@ -133,6 +138,8 @@ class Member(namedtuple('Member', 'index,name,session,data')):
         else:
             try:
                 data = json.loads(data)
+                if not isinstance(data, dict):
+                    data = {}
             except (TypeError, ValueError):
                 data = {}
         return Member(index, name, session, data)
@@ -153,7 +160,7 @@ class Member(namedtuple('Member', 'index,name,session,data')):
         defaults = {
             "host": None,
             "port": None,
-            "database": None
+            "dbname": None
         }
         ret = self.data.get('conn_kwargs')
         if ret:
@@ -167,7 +174,7 @@ class Member(namedtuple('Member', 'index,name,session,data')):
             ret = {
                 'host': r.hostname,
                 'port': r.port or 5432,
-                'database': r.path[1:]
+                'dbname': r.path[1:]
             }
             self.data['conn_kwargs'] = ret.copy()
 
@@ -206,6 +213,15 @@ class Member(namedtuple('Member', 'index,name,session,data')):
     def is_running(self):
         return self.state == 'running'
 
+    @property
+    def version(self):
+        version = self.data.get('version')
+        if version:
+            try:
+                return tuple(map(int, version.split('.')))
+            except Exception:
+                logger.debug('Failed to parse Patroni version %s', version)
+
 
 class RemoteMember(Member):
     """ Represents a remote master for a standby cluster
@@ -259,14 +275,10 @@ class Leader(namedtuple('Leader', 'index,session,member')):
         """
         >>> Leader(1, '', Member.from_node(1, '', '', '{"version":"z"}')).checkpoint_after_promote
         """
-        version = self.data.get('version')
-        if version:
-            try:
-                # 1.5.6 is the last version which doesn't expose checkpoint_after_promote: false
-                if tuple(map(int, version.split('.'))) > (1, 5, 6):
-                    return self.data['role'] == 'master' and 'checkpoint_after_promote' not in self.data
-            except Exception:
-                logger.debug('Failed to parse Patroni version %s', version)
+        version = self.member.version
+        # 1.5.6 is the last version which doesn't expose checkpoint_after_promote: false
+        if version and version > (1, 5, 6):
+            return self.data.get('role') == 'master' and 'checkpoint_after_promote' not in self.data
 
 
 class Failover(namedtuple('Failover', 'index,leader,candidate,scheduled_at')):
@@ -341,6 +353,10 @@ class ClusterConfig(namedtuple('ClusterConfig', 'index,data,modify_index')):
                 self.data.get('permanent_slots') or self.data.get('slots')
         ) or {}
 
+    @property
+    def ignore_slots_matchers(self):
+        return isinstance(self.data, dict) and self.data.get('ignore_slots') or []
+
     @property
     def max_timelines_history(self):
         return self.data.get('max_timelines_history', 0)
@@ -351,7 +367,7 @@ class SyncState(namedtuple('SyncState', 'index,leader,sync_standby')):
 
     :param index: modification index of a synchronization key in a Configuration Store
     :param leader: reference to member that was leader
-    :param sync_standby: standby that was last synchronized to leader
+    :param sync_standby: synchronous standby list (comma delimited) which are last synchronized to leader
     """
 
     @staticmethod
@@ -383,15 +399,22 @@ class SyncState(namedtuple('SyncState', 'index,leader,sync_standby')):
             data = {}
         return SyncState(index, data.get('leader'), data.get('sync_standby'))
 
+    @property
+    def members(self):
+        """ Returns sync_standby in list """
+        return self.sync_standby and self.sync_standby.split(',') or []
+
     def matches(self, name):
         """
         Returns if a node name matches one of the nodes in the sync state
 
-        >>> s = SyncState(1, 'foo', 'bar')
+        >>> s = SyncState(1, 'foo', 'bar,zoo')
         >>> s.matches('foo')
         True
         >>> s.matches('bar')
         True
+        >>> s.matches('zoo')
+        True
         >>> s.matches('baz')
         False
         >>> s.matches(None)
@@ -399,7 +422,7 @@ class SyncState(namedtuple('SyncState', 'index,leader,sync_standby')):
         >>> SyncState(1, None, None).matches('foo')
         False
         """
-        return name is not None and name in (self.leader, self.sync_standby)
+        return name is not None and name in [self.leader] + self.members
 
 
 class TimelineHistory(namedtuple('TimelineHistory', 'index,value,lines')):
@@ -421,19 +444,20 @@ class TimelineHistory(namedtuple('TimelineHistory', 'index,value,lines')):
         return TimelineHistory(index, value, lines)
 
 
-class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operation,members,failover,sync,history')):
+class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_lsn,members,failover,sync,history,slots')):
 
     """Immutable object (namedtuple) which represents PostgreSQL cluster.
     Consists of the following fields:
     :param initialize: shows whether this cluster has initialization key stored in DC or not.
     :param config: global dynamic configuration, reference to `ClusterConfig` object
     :param leader: `Leader` object which represents current leader of the cluster
-    :param last_leader_operation: int or long object containing position of last known leader operation.
-        This value is stored in `/optime/leader` key
+    :param last_lsn: int or long object containing position of last known leader LSN.
+        This value is stored in the `/status` key or `/optime/leader` (legacy) key
     :param members: list of Member object, all PostgreSQL cluster members including leader
     :param failover: reference to `Failover` object
     :param sync: reference to `SyncState` object, last observed synchronous replication state.
     :param history: reference to `TimelineHistory` object
+    :param slots: state of permanent logical replication slots on the primary in the format: {"slot_name": int}
     """
 
     def is_unlocked(self):
@@ -459,22 +483,41 @@ class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operat
     def is_synchronous_mode(self):
         return self.check_mode('synchronous_mode')
 
-    def get_replication_slots(self, my_name, role):
+    @property
+    def __permanent_slots(self):
+        return self.config and self.config.permanent_slots or {}
+
+    @property
+    def __permanent_physical_slots(self):
+        return {name: value for name, value in self.__permanent_slots.items()
+                if not value or isinstance(value, dict) and value.get('type', 'physical') == 'physical'}
+
+    @property
+    def __permanent_logical_slots(self):
+        return {name: value for name, value in self.__permanent_slots.items() if isinstance(value, dict)
+                and value.get('type', 'logical') == 'logical' and value.get('database') and value.get('plugin')}
+
+    @property
+    def use_slots(self):
+        return self.config and (self.config.data.get('postgresql') or {}).get('use_slots', True)
+
+    def get_replication_slots(self, my_name, role, nofailover, major_version, show_error=False):
         # if the replicatefrom tag is set on the member - we should not create the replication slot for it on
         # the current master, because that member would replicate from elsewhere. We still create the slot if
         # the replicatefrom destination member is currently not a member of the cluster (fallback to the
         # master), or if replicatefrom destination member happens to be the current master
-        use_slots = self.config and self.config.data.get('postgresql', {}).get('use_slots', True)
+        use_slots = self.use_slots
         if role in ('master', 'standby_leader'):
             slot_members = [m.name for m in self.members if use_slots and m.name != my_name and
                             (m.replicatefrom is None or m.replicatefrom == my_name or
                              not self.has_member(m.replicatefrom))]
-            permanent_slots = (self.config and self.config.permanent_slots or {}).copy()
+            permanent_slots = self.__permanent_slots if use_slots and \
+                role == 'master' else self.__permanent_physical_slots
         else:
             # only manage slots for replicas that replicate from this one, except for the leader among them
             slot_members = [m.name for m in self.members if use_slots and
                             m.replicatefrom == my_name and m.name != self.leader.name]
-            permanent_slots = {}
+            permanent_slots = self.__permanent_logical_slots if use_slots and not nofailover else {}
 
         slots = {slot_name_from_member_name(name): {'type': 'physical'} for name in slot_members}
 
@@ -488,6 +531,7 @@ class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operat
                                    for k, v in slot_conflicts.items() if len(v) > 1))
 
         # "merge" replication slots for members with permanent_replication_slots
+        disabled_permanent_logical_slots = []
         for name, value in permanent_slots.items():
             if not slot_name_re.match(name):
                 logger.error("Invalid permanent replication slot name '%s'", name)
@@ -500,11 +544,14 @@ class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operat
                     value['type'] = 'logical' if value.get('database') and value.get('plugin') else 'physical'
 
                 if value['type'] == 'physical':
-                    if name != my_name:  # Don't try to create permanent physical replication slot for yourself
+                    # Don't try to create permanent physical replication slot for yourself
+                    if name != slot_name_from_member_name(my_name):
                         slots[name] = value
                     continue
                 elif value['type'] == 'logical' and value.get('database') and value.get('plugin'):
-                    if name in slots:
+                    if major_version < 110000:
+                        disabled_permanent_logical_slots.append(name)
+                    elif name in slots:
                         logger.error("Permanent logical replication slot {'%s': %s} is conflicting with" +
                                      " physical replication slot for cluster member", name, value)
                     else:
@@ -513,20 +560,53 @@ class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operat
 
             logger.error("Bad value for slot '%s' in permanent_slots: %s", name, permanent_slots[name])
 
+        if disabled_permanent_logical_slots and show_error:
+            logger.error("Permanent logical replication slots supported by Patroni only starting from PostgreSQL 11. "
+                         "Following slots will not be created: %s.", disabled_permanent_logical_slots)
+
         return slots
 
-    def has_permanent_logical_slots(self, name):
-        slots = self.get_replication_slots(name, 'master').values()
+    def has_permanent_logical_slots(self, my_name, nofailover, major_version=110000):
+        if major_version < 110000:
+            return False
+        slots = self.get_replication_slots(my_name, 'replica', nofailover, major_version).values()
         return any(v for v in slots if v.get("type") == "logical")
 
+    def should_enforce_hot_standby_feedback(self, my_name, nofailover, major_version):
+        """
+        The hot_standby_feedback must be enabled if the current replica has logical slots
+        or it is working as a cascading replica for the other node that has logical slots.
+        """
+
+        if major_version < 110000:
+            return False
+
+        if self.has_permanent_logical_slots(my_name, nofailover, major_version):
+            return True
+
+        if self.use_slots:
+            members = [m for m in self.members if m.replicatefrom == my_name and m.name != self.leader.name]
+            return any(self.should_enforce_hot_standby_feedback(m.name, m.nofailover, major_version) for m in members)
+        return False
+
+    def get_my_slot_name_on_primary(self, my_name, replicatefrom):
+        """
+        P <-- I <-- L
+        In case of cascading replication we have to check not our physical slot,
+        but slot of the replica that connects us to the primary.
+        """
+
+        m = self.get_member(replicatefrom, False) if replicatefrom else None
+        return self.get_my_slot_name_on_primary(m.name, m.replicatefrom) if m else slot_name_from_member_name(my_name)
+
     @property
     def timeline(self):
         """
-        >>> Cluster(0, 0, 0, 0, 0, 0, 0, 0).timeline
+        >>> Cluster(0, 0, 0, 0, 0, 0, 0, 0, 0).timeline
         0
-        >>> Cluster(0, 0, 0, 0, 0, 0, 0, TimelineHistory.from_node(1, '[]')).timeline
+        >>> Cluster(0, 0, 0, 0, 0, 0, 0, TimelineHistory.from_node(1, '[]'), 0).timeline
         1
-        >>> Cluster(0, 0, 0, 0, 0, 0, 0, TimelineHistory.from_node(1, '[["a"]]')).timeline
+        >>> Cluster(0, 0, 0, 0, 0, 0, 0, TimelineHistory.from_node(1, '[["a"]]'), 0).timeline
         0
         """
         if self.history:
@@ -539,6 +619,10 @@ class Cluster(namedtuple('Cluster', 'initialize,config,leader,last_leader_operat
                 return 1
         return 0
 
+    @property
+    def min_version(self):
+        return next(iter(sorted(filter(lambda v: v, [m.version for m in self.members])) + [None]))
+
 
 @six.add_metaclass(abc.ABCMeta)
 class AbstractDCS(object):
@@ -550,7 +634,8 @@ class AbstractDCS(object):
     _HISTORY = 'history'
     _MEMBERS = 'members/'
     _OPTIME = 'optime'
-    _LEADER_OPTIME = _OPTIME + '/' + _LEADER
+    _STATUS = 'status'  # JSON, contains "leader_lsn" and confirmed_flush_lsn of logical "slots" on the leader
+    _LEADER_OPTIME = _OPTIME + '/' + _LEADER  # legacy
     _SYNC = 'sync'
 
     def __init__(self, config):
@@ -566,7 +651,9 @@ class AbstractDCS(object):
         self._cluster = None
         self._cluster_valid_till = 0
         self._cluster_thread_lock = Lock()
-        self._last_leader_operation = ''
+        self._last_lsn = ''
+        self._last_seen = 0
+        self._last_status = {}
         self.event = Event()
 
     def client_path(self, path):
@@ -600,6 +687,10 @@ class AbstractDCS(object):
     def history_path(self):
         return self.client_path(self._HISTORY)
 
+    @property
+    def status_path(self):
+        return self.client_path(self._STATUS)
+
     @property
     def leader_optime_path(self):
         return self.client_path(self._LEADER_OPTIME)
@@ -632,6 +723,10 @@ class AbstractDCS(object):
     def loop_wait(self):
         return self._loop_wait
 
+    @property
+    def last_seen(self):
+        return self._last_seen
+
     @abc.abstractmethod
     def _load_cluster(self):
         """Internally this method should build  `Cluster` object which
@@ -642,13 +737,20 @@ class AbstractDCS(object):
            If the current node was running as a master and exception raised,
            instance would be demoted."""
 
-    def get_cluster(self):
+    def _bypass_caches(self):
+        """Used only in zookeeper"""
+
+    def get_cluster(self, force=False):
+        if force:
+            self._bypass_caches()
         try:
             cluster = self._load_cluster()
         except Exception:
             self.reset_cluster()
             raise
 
+        self._last_seen = int(time.time())
+
         with self._cluster_thread_lock:
             self._cluster = cluster
             self._cluster_valid_till = time.time() + self.ttl
@@ -665,14 +767,30 @@ class AbstractDCS(object):
             self._cluster_valid_till = 0
 
     @abc.abstractmethod
-    def _write_leader_optime(self, last_operation):
-        """write current xlog location into `/optime/leader` key in DCS
-        :param last_operation: absolute xlog location in bytes
+    def _write_leader_optime(self, last_lsn):
+        """write current WAL LSN into `/optime/leader` key in DCS
+
+        :param last_lsn: absolute WAL LSN in bytes
         :returns: `!True` on success."""
 
-    def write_leader_optime(self, last_operation):
-        if self._last_leader_operation != last_operation and self._write_leader_optime(last_operation):
-            self._last_leader_operation = last_operation
+    def write_leader_optime(self, last_lsn):
+        self.write_status({self._OPTIME: last_lsn})
+
+    @abc.abstractmethod
+    def _write_status(self, value):
+        """write current WAL LSN and confirmed_flush_lsn of permanent slots into the `/status` key in DCS
+
+        :param value: status serialized in JSON forman
+        :returns: `!True` on success."""
+
+    def write_status(self, value):
+        if not deep_compare(self._last_status, value) and self._write_status(json.dumps(value, separators=(',', ':'))):
+            self._last_status = value
+        cluster = self.cluster
+        min_version = cluster and cluster.min_version
+        if min_version and min_version < (2, 1, 0) and self._last_lsn != value[self._OPTIME]:
+            self._last_lsn = value[self._OPTIME]
+            self._write_leader_optime(str(value[self._OPTIME]))
 
     @abc.abstractmethod
     def _update_leader(self):
@@ -684,16 +802,20 @@ class AbstractDCS(object):
         You have to use CAS (Compare And Swap) operation in order to update leader key,
         for example for etcd `prevValue` parameter must be used."""
 
-    def update_leader(self, last_operation, access_is_restricted=False):
+    def update_leader(self, last_lsn, slots=None):
         """Update leader key (or session) ttl and optime/leader
 
-        :param last_operation: absolute xlog location in bytes
+        :param last_lsn: absolute WAL LSN in bytes
+        :param slots: dict with permanent slots confirmed_flush_lsn
         :returns: `!True` if leader key (or session) has been updated successfully.
             If not, `!False` must be returned and current instance would be demoted."""
 
         ret = self._update_leader()
-        if ret and last_operation:
-            self.write_leader_optime(last_operation)
+        if ret and last_lsn:
+            status = {self._OPTIME: last_lsn}
+            if slots:
+                status['slots'] = slots
+            self.write_status(status)
         return ret
 
     @abc.abstractmethod
@@ -758,10 +880,19 @@ class AbstractDCS(object):
         otherwise it should return `!False`"""
 
     @abc.abstractmethod
-    def delete_leader(self):
-        """Voluntarily remove leader key from DCS
+    def _delete_leader(self):
+        """Remove leader key from DCS.
         This method should remove leader key if current instance is the leader"""
 
+    def delete_leader(self, last_lsn=None):
+        """Update optime/leader and voluntarily remove leader key from DCS.
+        This method should remove leader key if current instance is the leader.
+        :param last_lsn: latest checkpoint location in bytes"""
+
+        if last_lsn:
+            self.write_status({self._OPTIME: last_lsn})
+        return self._delete_leader()
+
     @abc.abstractmethod
     def cancel_initialization(self):
         """ Removes the initialize key for a cluster """
@@ -772,8 +903,10 @@ class AbstractDCS(object):
 
     @staticmethod
     def sync_state(leader, sync_standby):
-        """Build sync_state dict"""
-        return {'leader': leader, 'sync_standby': sync_standby}
+        """Build sync_state dict
+           sync_standby dictionary key being kept for backward compatibility
+        """
+        return {'leader': leader, 'sync_standby': sync_standby and ','.join(sorted(sync_standby)) or None}
 
     def write_sync_state(self, leader, sync_standby, index=None):
         sync_value = self.sync_state(leader, sync_standby)

patroni/dcs/consul.py

@@ -8,6 +8,7 @@ import ssl
 import time
 import urllib3
 
+from collections import namedtuple
 from consul import ConsulException, NotFound, base
 from urllib3.exceptions import HTTPError
 from six.moves.urllib.parse import urlencode, urlparse, quote
@@ -36,6 +37,9 @@ class InvalidSession(ConsulException):
     """invalid session"""
 
 
+Response = namedtuple('Response', 'code,headers,body,content')
+
+
 class HTTPClient(object):
 
     def __init__(self, host='127.0.0.1', port=8500, token=None, scheme='http', verify=True, cert=None, ca_cert=None):
@@ -54,7 +58,7 @@ class HTTPClient(object):
         if ca_cert:
             kwargs['ca_certs'] = ca_cert
         kwargs['cert_reqs'] = ssl.CERT_REQUIRED if verify or ca_cert else ssl.CERT_NONE
-        self.http = urllib3.PoolManager(num_pools=10, **kwargs)
+        self.http = urllib3.PoolManager(num_pools=10, maxsize=10, **kwargs)
         self._ttl = None
 
     def set_read_timeout(self, timeout):
@@ -71,16 +75,17 @@ class HTTPClient(object):
 
     @staticmethod
     def response(response):
-        data = response.data.decode('utf-8')
+        content = response.data
+        body = content.decode('utf-8')
         if response.status == 500:
-            msg = '{0} {1}'.format(response.status, data)
-            if data.startswith('Invalid Session TTL'):
+            msg = '{0} {1}'.format(response.status, body)
+            if body.startswith('Invalid Session TTL'):
                 raise InvalidSessionTTL(msg)
-            elif data.startswith('invalid session'):
+            elif body.startswith('invalid session'):
                 raise InvalidSession(msg)
             else:
                 raise ConsulInternalError(msg)
-        return base.Response(response.status, response.headers, data)
+        return Response(response.status, response.headers, body, content)
 
     def uri(self, path, params=None):
         return '{0}{1}{2}'.format(self.base_uri, path, params and '?' + urlencode(params) or '')
@@ -89,7 +94,7 @@ class HTTPClient(object):
         if method not in ('get', 'post', 'put', 'delete'):
             raise AttributeError("HTTPClient instance has no attribute '{0}'".format(method))
 
-        def wrapper(callback, path, params=None, data=''):
+        def wrapper(callback, path, params=None, data='', headers=None):
             # python-consul doesn't allow to specify ttl smaller then 10 seconds
             # because session_ttl_min defaults to 10s, so we have to do this ugly dirty hack...
             if method == 'put' and path == '/v1/session/create':
@@ -106,12 +111,13 @@ class HTTPClient(object):
                 # According to the documentation a small random amount of additional wait time is added to the
                 # supplied maximum wait time to spread out the wake up time of any concurrent requests. This adds
                 # up to wait / 16 additional time to the maximum duration. Since our goal is actually getting a
-                # response rather read timeout we will add to the timeout a sligtly bigger value.
+                # response rather read timeout we will add to the timeout a slightly bigger value.
                 kwargs['timeout'] = timeout + max(timeout/15.0, 1)
             else:
                 kwargs['timeout'] = self._read_timeout
+            kwargs['headers'] = (headers or {}).copy()
+            kwargs['headers'].update(urllib3.make_headers(user_agent=USER_AGENT))
             token = params.pop('token', self.token) if isinstance(params, dict) else self.token
-            kwargs['headers'] = urllib3.make_headers(user_agent=USER_AGENT)
             if token:
                 kwargs['headers']['X-Consul-Token'] = token
             return callback(self.response(self.http.request(method.upper(), self.uri(path, params), **kwargs)))
@@ -126,7 +132,7 @@ class ConsulClient(base.Consul):
         self.token = kwargs.get('token')
         super(ConsulClient, self).__init__(*args, **kwargs)
 
-    def connect(self, *args, **kwargs):
+    def http_connect(self, *args, **kwargs):
         kwargs.update(dict(zip(['host', 'port', 'scheme', 'verify'], args)))
         if self._cert:
             kwargs['cert'] = self._cert
@@ -136,6 +142,9 @@ class ConsulClient(base.Consul):
             kwargs['token'] = self.token
         return HTTPClient(**kwargs)
 
+    def connect(self, *args, **kwargs):
+        return self.http_connect(*args, **kwargs)
+
     def reload_config(self, config):
         self.http.token = self.token = config.get('token')
         self.consistency = config.get('consistency', 'default')
@@ -218,11 +227,11 @@ class Consul(AbstractDCS):
         self._last_session_refresh = 0
         self.__session_checks = config.get('checks', [])
         self._register_service = config.get('register_service', False)
+        self._previous_loop_register_service = self._register_service
+        self._service_tags = sorted(config.get('service_tags', []))
+        self._previous_loop_service_tags = self._service_tags
         if self._register_service:
-            self._service_name = service_name_from_scope_name(self._scope)
-            if self._scope != self._service_name:
-                logger.warning('Using %s as consul service name instead of scope name %s', self._service_name,
-                               self._scope)
+            self._set_service_name()
         self._service_check_interval = config.get('service_check_interval', '5s')
         if not self._ctl:
             self.create_session()
@@ -240,7 +249,18 @@ class Consul(AbstractDCS):
 
     def reload_config(self, config):
         super(Consul, self).reload_config(config)
-        self._client.reload_config(config.get('consul', {}))
+
+        consul_config = config.get('consul', {})
+        self._client.reload_config(consul_config)
+        self._previous_loop_service_tags = self._service_tags
+        self._service_tags = sorted(consul_config.get('service_tags', []))
+
+        should_register_service = consul_config.get('register_service', False)
+        if should_register_service and not self._register_service:
+            self._set_service_name()
+
+        self._previous_loop_register_service = self._register_service
+        self._register_service = should_register_service
 
     def set_ttl(self, ttl):
         if self._client.http.set_ttl(ttl/2.0):  # Consul multiplies the TTL by 2x
@@ -327,9 +347,24 @@ class Consul(AbstractDCS):
             history = nodes.get(self._HISTORY)
             history = history and TimelineHistory.from_node(history['ModifyIndex'], history['Value'])
 
-            # get last leader operation
-            last_leader_operation = nodes.get(self._LEADER_OPTIME)
-            last_leader_operation = 0 if last_leader_operation is None else int(last_leader_operation['Value'])
+            # get last known leader lsn and slots
+            status = nodes.get(self._STATUS)
+            if status:
+                try:
+                    status = json.loads(status['Value'])
+                    last_lsn = status.get(self._OPTIME)
+                    slots = status.get('slots')
+                except Exception:
+                    slots = last_lsn = None
+            else:
+                last_lsn = nodes.get(self._LEADER_OPTIME)
+                last_lsn = last_lsn and last_lsn['Value']
+                slots = None
+
+            try:
+                last_lsn = int(last_lsn)
+            except Exception:
+                last_lsn = 0
 
             # get list of members
             members = [self.member(n) for k, n in nodes.items() if k.startswith(self._MEMBERS) and k.count('/') == 1]
@@ -356,9 +391,9 @@ class Consul(AbstractDCS):
             sync = nodes.get(self._SYNC)
             sync = SyncState.from_node(sync and sync['ModifyIndex'], sync and sync['Value'])
 
-            return Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+            return Cluster(initialize, config, leader, last_lsn, members, failover, sync, history, slots)
         except NotFound:
-            return Cluster(None, None, None, None, [], None, None, None)
+            return Cluster(None, None, None, None, [], None, None, None, None)
         except Exception:
             logger.exception('get_cluster')
             raise ConsulError('Consul is not responding properly')
@@ -367,20 +402,28 @@ class Consul(AbstractDCS):
     def touch_member(self, data, permanent=False):
         cluster = self.cluster
         member = cluster and cluster.get_member(self._name, fallback_to_leader=False)
-        create_member = not permanent and self.refresh_session()
+
+        try:
+            create_member = not permanent and self.refresh_session()
+        except DCSError:
+            return False
 
         if member and (create_member or member.session != self._session):
             self._client.kv.delete(self.member_path)
             create_member = True
 
+        if self._register_service or self._previous_loop_register_service:
+            try:
+                self.update_service(not create_member and member and member.data or {}, data)
+            except Exception:
+                logger.exception('update_service')
+
         if not create_member and member and deep_compare(data, member.data):
             return True
 
         try:
             args = {} if permanent else {'acquire': self._session}
             self._client.kv.put(self.member_path, json.dumps(data, separators=(',', ':')), **args)
-            if self._register_service:
-                self.update_service(not create_member and member and member.data or {}, data)
             return True
         except InvalidSession:
             self._session = None
@@ -389,6 +432,11 @@ class Consul(AbstractDCS):
             logger.exception('touch_member')
         return False
 
+    def _set_service_name(self):
+        self._service_name = service_name_from_scope_name(self._scope)
+        if self._scope != self._service_name:
+            logger.warning('Using %s as consul service name instead of scope name %s', self._service_name, self._scope)
+
     @catch_consul_errors
     def register_service(self, service_name, **kwargs):
         logger.info('Register service %s, params %s', service_name, kwargs)
@@ -410,17 +458,24 @@ class Consul(AbstractDCS):
         conn_parts = urlparse(data['conn_url'])
         check = base.Check.http(api_parts.geturl(), self._service_check_interval,
                                 deregister='{0}s'.format(self._client.http.ttl * 10))
+        tags = self._service_tags[:]
+        tags.append(role)
+        self._previous_loop_service_tags = self._service_tags
+
         params = {
             'service_id': '{0}/{1}'.format(self._scope, self._name),
             'address': conn_parts.hostname,
             'port': conn_parts.port,
             'check': check,
-            'tags': [role]
+            'tags': tags,
+            'enable_tag_override': True,
         }
 
-        if state == 'stopped':
+        if state == 'stopped' or (not self._register_service and self._previous_loop_register_service):
+            self._previous_loop_register_service = self._register_service
             return self.deregister_service(params['service_id'])
 
+        self._previous_loop_register_service = self._register_service
         if role in ['master', 'replica', 'standby-leader']:
             if state != 'running':
                 return
@@ -439,7 +494,10 @@ class Consul(AbstractDCS):
             if old_data.get(key) != new_data[key]:
                 update = True
 
-        if force or update:
+        if (
+            force or update or self._register_service != self._previous_loop_register_service
+            or self._service_tags != self._previous_loop_service_tags
+        ):
             return self._update_service(new_data)
 
     @catch_consul_errors
@@ -475,8 +533,12 @@ class Consul(AbstractDCS):
         return self._client.kv.put(self.config_path, value, cas=index)
 
     @catch_consul_errors
-    def _write_leader_optime(self, last_operation):
-        return self._client.kv.put(self.leader_optime_path, last_operation)
+    def _write_leader_optime(self, last_lsn):
+        return self._client.kv.put(self.leader_optime_path, last_lsn)
+
+    @catch_consul_errors
+    def _write_status(self, value):
+        return self._client.kv.put(self.status_path, value)
 
     @catch_consul_errors
     def _update_leader(self):
@@ -503,7 +565,7 @@ class Consul(AbstractDCS):
         return self._client.kv.put(self.history_path, value)
 
     @catch_consul_errors
-    def delete_leader(self):
+    def _delete_leader(self):
         cluster = self.cluster
         if cluster and isinstance(cluster.leader, Leader) and cluster.leader.name == self._name:
             return self._client.kv.delete(self.leader_path, cas=cluster.leader.index)

patroni/dcs/etcd.py

@@ -1,4 +1,5 @@
 from __future__ import absolute_import
+import abc
 import etcd
 import json
 import logging
@@ -82,7 +83,8 @@ class DnsCachingResolver(Thread):
             return []
 
 
-class Client(etcd.Client):
+@six.add_metaclass(abc.ABCMeta)
+class AbstractEtcdClientWithFailover(etcd.Client):
 
     def __init__(self, config, dns_resolver, cache_ttl=300):
         self._dns_resolver = dns_resolver
@@ -90,7 +92,7 @@ class Client(etcd.Client):
         self._machines_cache_updated = 0
         args = {p: config.get(p) for p in ('host', 'port', 'protocol', 'use_proxies', 'username', 'password',
                                            'cert', 'ca_cert') if config.get(p)}
-        super(Client, self).__init__(read_timeout=config['retry_timeout'], **args)
+        super(AbstractEtcdClientWithFailover, self).__init__(read_timeout=config['retry_timeout'], **args)
         # For some reason python3-etcd on debian and ubuntu are not based on the latest version
         # Workaround for the case when https://github.com/jplana/python-etcd/pull/196 is not applied
         self.http.connection_pool_kw.pop('ssl_version', None)
@@ -130,12 +132,16 @@ class Client(etcd.Client):
 
         return etcd_nodes, per_node_timeout, per_node_retries - 1
 
+    def reload_config(self, config):
+        self.username = config.get('username')
+        self.password = config.get('password')
+
     def _get_headers(self):
         basic_auth = ':'.join((self.username, self.password)) if self.username and self.password else None
         return urllib3.make_headers(basic_auth=basic_auth, user_agent=USER_AGENT)
 
-    def _build_request_parameters(self, etcd_nodes, timeout=None):
-        kwargs = {'headers': self._get_headers(), 'redirect': self.allow_redirect}
+    def _prepare_common_parameters(self, etcd_nodes, timeout=None):
+        kwargs = {'headers': self._get_headers(), 'redirect': self.allow_redirect, 'preload_content': False}
 
         if timeout is not None:
             kwargs.update(retries=0, timeout=timeout)
@@ -148,6 +154,14 @@ class Client(etcd.Client):
     def set_machines_cache_ttl(self, cache_ttl):
         self._machines_cache_ttl = cache_ttl
 
+    @abc.abstractmethod
+    def _prepare_get_members(self, etcd_nodes):
+        """returns: request parameters"""
+
+    @abc.abstractmethod
+    def _get_members(self, base_uri, **kwargs):
+        """returns: list of clientURLs"""
+
     @property
     def machines_cache(self):
         base_uri, cache = self._base_uri, self._machines_cache
@@ -166,17 +180,16 @@ class Client(etcd.Client):
         the original method was retrying 2 times with the `read_timeout` on each node."""
 
         machines_cache = self.machines_cache
-        kwargs = self._build_request_parameters(len(machines_cache))
+        kwargs = self._prepare_get_members(len(machines_cache))
 
         for base_uri in machines_cache:
             try:
-                response = self.http.request(self._MGET, base_uri + self.version_prefix + '/machines', **kwargs)
-                data = self._handle_server_response(response).data.decode('utf-8')
-                machines = [m.strip() for m in data.split(',') if m.strip()]
+                machines = list(set(self._get_members(base_uri, **kwargs)))
                 logger.debug("Retrieved list of machines: %s", machines)
                 if machines:
                     random.shuffle(machines)
-                    self._update_dns_cache(self._dns_resolver.resolve_async, machines)
+                    if not self._use_proxies:
+                        self._update_dns_cache(self._dns_resolver.resolve_async, machines)
                     return machines
             except Exception as e:
                 self.http.clear()
@@ -188,14 +201,15 @@ class Client(etcd.Client):
         self._read_timeout = timeout
 
     def _do_http_request(self, retry, machines_cache, request_executor, method, path, fields=None, **kwargs):
+        if fields is not None:
+            kwargs['fields'] = fields
         some_request_failed = False
         for i, base_uri in enumerate(machines_cache):
             if i > 0:
                 logger.info("Retrying on %s", base_uri)
             try:
-                response = request_executor(method, base_uri + path, fields=fields, **kwargs)
+                response = request_executor(method, base_uri + path, **kwargs)
                 response.data.decode('utf-8')
-                self._check_cluster_id(response)
                 if some_request_failed:
                     self.set_base_uri(base_uri)
                     self._refresh_machines_cache()
@@ -218,20 +232,12 @@ class Client(etcd.Client):
 
         raise etcd.EtcdConnectionFailed('No more machines in the cluster')
 
+    @abc.abstractmethod
+    def _prepare_request(self, kwargs, params=None, method=None):
+        """returns: request_executor"""
+
     def api_execute(self, path, method, params=None, timeout=None):
-        if not path.startswith('/'):
-            raise ValueError('Path does not start with /')
-
         retry = params.pop('retry', None) if isinstance(params, dict) else None
-        kwargs = {'fields': params, 'preload_content': False}
-
-        if method in [self._MGET, self._MDELETE]:
-            request_executor = self.http.request
-        elif method in [self._MPUT, self._MPOST]:
-            request_executor = self.http.request_encode_body
-            kwargs['encode_multipart'] = False
-        else:
-            raise etcd.EtcdException('HTTP method {0} not supported'.format(method))
 
         # Update machines_cache if previous attempt of update has failed
         if self._update_machines_cache:
@@ -241,7 +247,9 @@ class Client(etcd.Client):
 
         machines_cache = self.machines_cache
         etcd_nodes = len(machines_cache)
-        kwargs.update(self._build_request_parameters(etcd_nodes, timeout))
+
+        kwargs = self._prepare_common_parameters(etcd_nodes, timeout)
+        request_executor = self._prepare_request(kwargs, params, method)
 
         while True:
             try:
@@ -275,13 +283,14 @@ class Client(etcd.Client):
         except DNSException:
             return []
 
-    def _get_machines_cache_from_srv(self, srv):
+    def _get_machines_cache_from_srv(self, srv, srv_suffix=None):
         """Fetch list of etcd-cluster member by resolving _etcd-server._tcp. SRV record.
         This record should contain list of host and peer ports which could be used to run
         'GET http://{host}:{port}/members' request (peer protocol)"""
 
         ret = []
         for r in ['-client-ssl', '-client', '-ssl', '', '-server-ssl', '-server']:
+            r = '{0}-{1}'.format(r, srv_suffix) if srv_suffix else r
             protocol = 'https' if '-ssl' in r else 'http'
             endpoint = '/members' if '-server' in r else ''
             for host, port in self.get_srv_record('_etcd{0}._tcp.{1}'.format(r, srv)):
@@ -318,7 +327,7 @@ class Client(etcd.Client):
 
         machines_cache = []
         if 'srv' in self._config:
-            machines_cache = self._get_machines_cache_from_srv(self._config['srv'])
+            machines_cache = self._get_machines_cache_from_srv(self._config['srv'], self._config.get('srv_suffix'))
 
         if not machines_cache and 'hosts' in self._config:
             machines_cache = list(self._config['hosts'])
@@ -389,17 +398,47 @@ class Client(etcd.Client):
         self._base_uri = value
 
 
-class Etcd(AbstractDCS):
+class EtcdClient(AbstractEtcdClientWithFailover):
 
-    def __init__(self, config):
-        super(Etcd, self).__init__(config)
-        self._ttl = int(config.get('ttl') or 30)
+    ERROR_CLS = EtcdError
+
+    def __del__(self):
+        if self.http is not None:
+            try:
+                self.http.clear()
+            except (ReferenceError, TypeError, AttributeError):
+                pass
+
+    def _prepare_get_members(self, etcd_nodes):
+        return self._prepare_common_parameters(etcd_nodes)
+
+    def _get_members(self, base_uri, **kwargs):
+        response = self.http.request(self._MGET, base_uri + self.version_prefix + '/machines', **kwargs)
+        data = self._handle_server_response(response).data.decode('utf-8')
+        return [m.strip() for m in data.split(',') if m.strip()]
+
+    def _prepare_request(self, kwargs, params=None, method=None):
+        kwargs['fields'] = params
+        if method in (self._MPOST, self._MPUT):
+            kwargs['encode_multipart'] = False
+        return self.http.request
+
+
+class AbstractEtcd(AbstractDCS):
+
+    def __init__(self, config, client_cls, retry_errors_cls):
+        super(AbstractEtcd, self).__init__(config)
         self._retry = Retry(deadline=config['retry_timeout'], max_delay=1, max_tries=-1,
-                            retry_exceptions=(etcd.EtcdLeaderElectionInProgress, EtcdRaftInternal))
-        self._client = self.get_etcd_client(config)
+                            retry_exceptions=retry_errors_cls)
+        self._ttl = int(config.get('ttl') or 30)
+        self._client = self.get_etcd_client(config, client_cls)
         self.__do_not_watch = False
         self._has_failed = False
 
+    def reload_config(self, config):
+        super(AbstractEtcd, self).reload_config(config)
+        self._client.reload_config(config.get(self.__class__.__name__.lower(), {}))
+
     def retry(self, *args, **kwargs):
         retry = self._retry.copy()
         kwargs['retry'] = retry
@@ -416,22 +455,13 @@ class Etcd(AbstractDCS):
         if isinstance(raise_ex, Exception):
             raise raise_ex
 
-    def catch_etcd_errors(func):
-        def wrapper(self, *args, **kwargs):
-            try:
-                retval = func(self, *args, **kwargs) is not None
-                self._has_failed = False
-                return retval
-            except (RetryFailedError, etcd.EtcdException) as e:
-                self._handle_exception(e)
-                return False
-            except Exception as e:
-                self._handle_exception(e, raise_ex=EtcdError('unexpected error'))
-
-        return wrapper
-
     @staticmethod
-    def get_etcd_client(config):
+    def set_socket_options(sock, socket_options):
+        if socket_options:
+            for opt in socket_options:
+                sock.setsockopt(*opt)
+
+    def get_etcd_client(self, config, client_cls):
         if 'proxy' in config:
             config['use_proxies'] = True
             config['url'] = config['proxy']
@@ -480,9 +510,7 @@ class Etcd(AbstractDCS):
                 sock = None
                 try:
                     sock = socket.socket(af, socktype, proto)
-                    if socket_options:
-                        for opt in socket_options:
-                            sock.setsockopt(*opt)
+                    self.set_socket_options(sock, socket_options)
                     if timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
                         sock.settimeout(timeout)
                     if source_address:
@@ -506,7 +534,7 @@ class Etcd(AbstractDCS):
         client = None
         while not client:
             try:
-                client = Client(config, dns_resolver)
+                client = client_cls(config, dns_resolver)
                 if 'use_proxies' in config and not client.machines:
                     raise etcd.EtcdException
             except etcd.EtcdException:
@@ -516,9 +544,10 @@ class Etcd(AbstractDCS):
 
     def set_ttl(self, ttl):
         ttl = int(ttl)
-        self.__do_not_watch = self._ttl != ttl
+        ret = self._ttl != ttl
         self._ttl = ttl
         self._client.set_machines_cache_ttl(ttl*10)
+        return ret
 
     @property
     def ttl(self):
@@ -528,6 +557,31 @@ class Etcd(AbstractDCS):
         self._retry.deadline = retry_timeout
         self._client.set_read_timeout(retry_timeout)
 
+
+def catch_etcd_errors(func):
+    def wrapper(self, *args, **kwargs):
+        try:
+            retval = func(self, *args, **kwargs) is not None
+            self._has_failed = False
+            return retval
+        except (RetryFailedError, etcd.EtcdException) as e:
+            self._handle_exception(e)
+            return False
+        except Exception as e:
+            self._handle_exception(e, raise_ex=self._client.ERROR_CLS('unexpected error'))
+
+    return wrapper
+
+
+class Etcd(AbstractEtcd):
+
+    def __init__(self, config):
+        super(Etcd, self).__init__(config, EtcdClient, (etcd.EtcdLeaderElectionInProgress, EtcdRaftInternal))
+        self.__do_not_watch = False
+
+    def set_ttl(self, ttl):
+        self.__do_not_watch = super(Etcd, self).set_ttl(ttl)
+
     @staticmethod
     def member(node):
         return Member.from_node(node.modifiedIndex, os.path.basename(node.key), node.ttl, node.value)
@@ -550,9 +604,24 @@ class Etcd(AbstractDCS):
             history = nodes.get(self._HISTORY)
             history = history and TimelineHistory.from_node(history.modifiedIndex, history.value)
 
-            # get last leader operation
-            last_leader_operation = nodes.get(self._LEADER_OPTIME)
-            last_leader_operation = 0 if last_leader_operation is None else int(last_leader_operation.value)
+            # get last know leader lsn and slots
+            status = nodes.get(self._STATUS)
+            if status:
+                try:
+                    status = json.loads(status.value)
+                    last_lsn = status.get(self._OPTIME)
+                    slots = status.get('slots')
+                except Exception:
+                    slots = last_lsn = None
+            else:
+                last_lsn = nodes.get(self._LEADER_OPTIME)
+                last_lsn = last_lsn and last_lsn.value
+                slots = None
+
+            try:
+                last_lsn = int(last_lsn)
+            except Exception:
+                last_lsn = 0
 
             # get list of members
             members = [self.member(n) for k, n in nodes.items() if k.startswith(self._MEMBERS) and k.count('/') == 1]
@@ -574,9 +643,9 @@ class Etcd(AbstractDCS):
             sync = nodes.get(self._SYNC)
             sync = SyncState.from_node(sync and sync.modifiedIndex, sync and sync.value)
 
-            cluster = Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+            cluster = Cluster(initialize, config, leader, last_lsn, members, failover, sync, history, slots)
         except etcd.EtcdKeyNotFound:
-            cluster = Cluster(None, None, None, None, [], None, None, None)
+            cluster = Cluster(None, None, None, None, [], None, None, None, None)
         except Exception as e:
             self._handle_exception(e, 'get_cluster', raise_ex=EtcdError('Etcd is not responding properly'))
         self._has_failed = False
@@ -613,8 +682,12 @@ class Etcd(AbstractDCS):
         return self._client.write(self.config_path, value, prevIndex=index or 0)
 
     @catch_etcd_errors
-    def _write_leader_optime(self, last_operation):
-        return self._client.set(self.leader_optime_path, last_operation)
+    def _write_leader_optime(self, last_lsn):
+        return self._client.set(self.leader_optime_path, last_lsn)
+
+    @catch_etcd_errors
+    def _write_status(self, value):
+        return self._client.set(self.status_path, value)
 
     @catch_etcd_errors
     def _update_leader(self):
@@ -625,7 +698,7 @@ class Etcd(AbstractDCS):
         return self.retry(self._client.write, self.initialize_path, sysid, prevExist=(not create_new))
 
     @catch_etcd_errors
-    def delete_leader(self):
+    def _delete_leader(self):
         return self._client.delete(self.leader_path, prevValue=self._name)
 
     @catch_etcd_errors
@@ -658,8 +731,10 @@ class Etcd(AbstractDCS):
 
             while timeout >= 1:  # when timeout is too small urllib3 doesn't have enough time to connect
                 try:
-                    self._client.watch(self.leader_path, index=leader_index, timeout=timeout + 0.5)
+                    result = self._client.watch(self.leader_path, index=leader_index, timeout=timeout + 0.5)
                     self._has_failed = False
+                    if result.action == 'compareAndSwap':
+                        time.sleep(0.01)
                     # Synchronous work of all cluster members with etcd is less expensive
                     # than reestablishing http connection every time from every replica.
                     return True

patroni/dcs/etcd3.py

@@ -0,0 +1,823 @@
+from __future__ import absolute_import
+import base64
+import etcd
+import json
+import logging
+import os
+import six
+import socket
+import sys
+import time
+import urllib3
+
+from threading import Condition, Lock, Thread
+
+from . import ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
+from .etcd import AbstractEtcdClientWithFailover, AbstractEtcd, catch_etcd_errors
+from ..exceptions import DCSError, PatroniException
+from ..utils import deep_compare, enable_keepalive, iter_response_objects, RetryFailedError, USER_AGENT
+
+logger = logging.getLogger(__name__)
+
+
+class Etcd3Error(DCSError):
+    pass
+
+
+class UnsupportedEtcdVersion(PatroniException):
+    pass
+
+
+# google.golang.org/grpc/codes
+GRPCCode = type('Enum', (), {'OK': 0, 'Canceled': 1, 'Unknown': 2, 'InvalidArgument': 3, 'DeadlineExceeded': 4,
+                             'NotFound': 5, 'AlreadyExists': 6, 'PermissionDenied': 7, 'ResourceExhausted': 8,
+                             'FailedPrecondition': 9, 'Aborted': 10, 'OutOfRange': 11, 'Unimplemented': 12,
+                             'Internal': 13, 'Unavailable': 14, 'DataLoss': 15, 'Unauthenticated': 16})
+GRPCcodeToText = {v: k for k, v in GRPCCode.__dict__.items() if not k.startswith('__') and isinstance(v, int)}
+
+
+class Etcd3Exception(etcd.EtcdException):
+    pass
+
+
+class Etcd3ClientError(Etcd3Exception):
+
+    def __init__(self, code=None, error=None, status=None):
+        if not hasattr(self, 'error'):
+            self.error = error and error.strip()
+        self.codeText = GRPCcodeToText.get(code)
+        self.status = status
+
+    def __repr__(self):
+        return "<{0} error: '{1}', code: {2}>".format(self.__class__.__name__, self.error, self.code)
+
+    __str__ = __repr__
+
+    def as_dict(self):
+        return {'error': self.error, 'code': self.code, 'codeText': self.codeText, 'status': self.status}
+
+    @classmethod
+    def get_subclasses(cls):
+        for subclass in cls.__subclasses__():
+            for subsubclass in subclass.get_subclasses():
+                yield subsubclass
+            yield subclass
+
+
+class Unknown(Etcd3ClientError):
+    code = GRPCCode.Unknown
+
+
+class InvalidArgument(Etcd3ClientError):
+    code = GRPCCode.InvalidArgument
+
+
+class DeadlineExceeded(Etcd3ClientError):
+    code = GRPCCode.DeadlineExceeded
+    error = "context deadline exceeded"
+
+
+class NotFound(Etcd3ClientError):
+    code = GRPCCode.NotFound
+
+
+class FailedPrecondition(Etcd3ClientError):
+    code = GRPCCode.FailedPrecondition
+
+
+class Unavailable(Etcd3ClientError):
+    code = GRPCCode.Unavailable
+
+
+# https://github.com/etcd-io/etcd/blob/master/etcdserver/api/v3rpc/rpctypes/error.go
+class LeaseNotFound(NotFound):
+    error = "etcdserver: requested lease not found"
+
+
+class UserEmpty(InvalidArgument):
+    error = "etcdserver: user name is empty"
+
+
+class AuthFailed(InvalidArgument):
+    error = "etcdserver: authentication failed, invalid user ID or password"
+
+
+class PermissionDenied(Etcd3ClientError):
+    code = GRPCCode.PermissionDenied
+    error = "etcdserver: permission denied"
+
+
+class AuthNotEnabled(FailedPrecondition):
+    error = "etcdserver: authentication is not enabled"
+
+
+class InvalidAuthToken(Etcd3ClientError):
+    code = GRPCCode.Unauthenticated
+    error = "etcdserver: invalid auth token"
+
+
+errStringToClientError = {s.error: s for s in Etcd3ClientError.get_subclasses() if hasattr(s, 'error')}
+errCodeToClientError = {s.code: s for s in Etcd3ClientError.__subclasses__()}
+
+
+def _raise_for_data(data, status_code=None):
+    try:
+        error = data.get('error') or data.get('Error')
+        if isinstance(error, dict):  # streaming response
+            status_code = error.get('http_code')
+            code = error['grpc_code']
+            error = error['message']
+        else:
+            code = data.get('code') or data.get('Code')
+    except Exception:
+        error = str(data)
+        code = GRPCCode.Unknown
+    err = errStringToClientError.get(error) or errCodeToClientError.get(code) or Unknown
+    raise err(code, error, status_code)
+
+
+def to_bytes(v):
+    return v if isinstance(v, bytes) else v.encode('utf-8')
+
+
+def prefix_range_end(v):
+    v = bytearray(to_bytes(v))
+    for i in range(len(v) - 1, -1, -1):
+        if v[i] < 0xff:
+            v[i] += 1
+            break
+    return bytes(v)
+
+
+def base64_encode(v):
+    return base64.b64encode(to_bytes(v)).decode('utf-8')
+
+
+def base64_decode(v):
+    return base64.b64decode(v).decode('utf-8')
+
+
+def build_range_request(key, range_end=None):
+    fields = {'key': base64_encode(key)}
+    if range_end:
+        fields['range_end'] = base64_encode(range_end)
+    return fields
+
+
+class Etcd3Client(AbstractEtcdClientWithFailover):
+
+    ERROR_CLS = Etcd3Error
+
+    def __init__(self, config, dns_resolver, cache_ttl=300):
+        self._token = None
+        self._cluster_version = None
+        self.version_prefix = '/v3beta'
+        super(Etcd3Client, self).__init__(config, dns_resolver, cache_ttl)
+
+        if six.PY2:  # pragma: no cover
+            # Old grpc-gateway sometimes sends double 'transfer-encoding: chunked' headers,
+            # what breaks the old (python2.7) httplib.HTTPConnection (it closes the socket).
+            def dedup_addheader(httpm, key, value):
+                prev = httpm.dict.get(key)
+                if prev is None:
+                    httpm.dict[key] = value
+                elif key != 'transfer-encoding' or prev != value:
+                    combined = ", ".join((prev, value))
+                    httpm.dict[key] = combined
+
+            import httplib
+            httplib.HTTPMessage.addheader = dedup_addheader
+
+        try:
+            self.authenticate()
+        except AuthFailed as e:
+            logger.fatal('Etcd3 authentication failed: %r', e)
+            sys.exit(1)
+
+    def _get_headers(self):
+        headers = urllib3.make_headers(user_agent=USER_AGENT)
+        if self._token and self._cluster_version >= (3, 3, 0):
+            headers['authorization'] = self._token
+        return headers
+
+    def _prepare_request(self, kwargs, params=None, method=None):
+        if params is not None:
+            kwargs['body'] = json.dumps(params)
+            kwargs['headers']['Content-Type'] = 'application/json'
+        return self.http.urlopen
+
+    @staticmethod
+    def _handle_server_response(response):
+        data = response.data
+        try:
+            data = data.decode('utf-8')
+            data = json.loads(data)
+        except (TypeError, ValueError, UnicodeError) as e:
+            if response.status < 400:
+                raise etcd.EtcdException('Server response was not valid JSON: %r' % e)
+        if response.status < 400:
+            return data
+        _raise_for_data(data, response.status)
+
+    def _ensure_version_prefix(self, base_uri, **kwargs):
+        if self.version_prefix != '/v3':
+            response = self.http.urlopen(self._MGET, base_uri + '/version', **kwargs)
+            response = self._handle_server_response(response)
+
+            server_version_str = response['etcdserver']
+            server_version = tuple(int(x) for x in server_version_str.split('.'))
+            cluster_version_str = response['etcdcluster']
+            self._cluster_version = tuple(int(x) for x in cluster_version_str.split('.'))
+
+            if self._cluster_version < (3, 0) or server_version < (3, 0, 4):
+                raise UnsupportedEtcdVersion('Detected Etcd version {0} is lower than 3.0.4'.format(server_version_str))
+
+            if self._cluster_version < (3, 3):
+                if self.version_prefix != '/v3alpha':
+                    if self._cluster_version < (3, 1):
+                        logger.warning('Detected Etcd version %s is lower than 3.1.0, watches are not supported',
+                                       cluster_version_str)
+                    if self.username and self.password:
+                        logger.warning('Detected Etcd version %s is lower than 3.3.0, authentication is not supported',
+                                       cluster_version_str)
+                    self.version_prefix = '/v3alpha'
+            elif self._cluster_version < (3, 4):
+                self.version_prefix = '/v3beta'
+            else:
+                self.version_prefix = '/v3'
+
+    def _prepare_get_members(self, etcd_nodes):
+        kwargs = self._prepare_common_parameters(etcd_nodes)
+        self._prepare_request(kwargs, {})
+        return kwargs
+
+    def _get_members(self, base_uri, **kwargs):
+        self._ensure_version_prefix(base_uri, **kwargs)
+        resp = self.http.urlopen(self._MPOST, base_uri + self.version_prefix + '/cluster/member/list', **kwargs)
+        members = self._handle_server_response(resp)['members']
+        return set(url for member in members for url in member.get('clientURLs', []))
+
+    def call_rpc(self, method, fields, retry=None):
+        fields['retry'] = retry
+        return self.api_execute(self.version_prefix + method, self._MPOST, fields)
+
+    def authenticate(self):
+        if self._use_proxies and self._cluster_version is None:
+            kwargs = self._prepare_common_parameters(1)
+            self._ensure_version_prefix(self._base_uri, **kwargs)
+        if self._cluster_version >= (3, 3) and self.username and self.password:
+            logger.info('Trying to authenticate on Etcd...')
+            old_token, self._token = self._token, None
+            try:
+                response = self.call_rpc('/auth/authenticate', {'name': self.username, 'password': self.password})
+            except AuthNotEnabled:
+                logger.info('Etcd authentication is not enabled')
+                self._token = None
+            except Exception:
+                self._token = old_token
+                raise
+            else:
+                self._token = response.get('token')
+            return old_token != self._token
+
+    def _handle_auth_errors(func):
+        def wrapper(self, *args, **kwargs):
+            def retry(ex):
+                if self.username and self.password:
+                    self.authenticate()
+                    return func(self, *args, **kwargs)
+                else:
+                    logger.fatal('Username or password not set, authentication is not possible')
+                    raise ex
+
+            try:
+                return func(self, *args, **kwargs)
+            except (UserEmpty, PermissionDenied) as e:  # no token provided
+                # PermissionDenied is raised on 3.0 and 3.1
+                if self._cluster_version < (3, 3) and (not isinstance(e, PermissionDenied)
+                                                       or self._cluster_version < (3, 2)):
+                    raise UnsupportedEtcdVersion('Authentication is required by Etcd cluster but not '
+                                                 'supported on version lower than 3.3.0. Cluster version: '
+                                                 '{0}'.format('.'.join(map(str, self._cluster_version))))
+                return retry(e)
+            except InvalidAuthToken as e:
+                logger.error('Invalid auth token: %s', self._token)
+                return retry(e)
+
+        return wrapper
+
+    @_handle_auth_errors
+    def range(self, key, range_end=None, retry=None):
+        params = build_range_request(key, range_end)
+        params['serializable'] = True  # For better performance. We can tolerate stale reads.
+        return self.call_rpc('/kv/range', params, retry)
+
+    def prefix(self, key, retry=None):
+        return self.range(key, prefix_range_end(key), retry)
+
+    def lease_grant(self, ttl, retry=None):
+        return self.call_rpc('/lease/grant', {'TTL': ttl}, retry)['ID']
+
+    def lease_keepalive(self, ID, retry=None):
+        return self.call_rpc('/lease/keepalive', {'ID': ID}, retry).get('result', {}).get('TTL')
+
+    def txn(self, compare, success, retry=None):
+        return self.call_rpc('/kv/txn', {'compare': [compare], 'success': [success]}, retry).get('succeeded')
+
+    @_handle_auth_errors
+    def put(self, key, value, lease=None, create_revision=None, mod_revision=None, retry=None):
+        fields = {'key': base64_encode(key), 'value': base64_encode(value)}
+        if lease:
+            fields['lease'] = lease
+        if create_revision is not None:
+            compare = {'target': 'CREATE', 'create_revision': create_revision}
+        elif mod_revision is not None:
+            compare = {'target': 'MOD', 'mod_revision': mod_revision}
+        else:
+            return self.call_rpc('/kv/put', fields, retry)
+        compare['key'] = fields['key']
+        return self.txn(compare, {'request_put': fields}, retry)
+
+    @_handle_auth_errors
+    def deleterange(self, key, range_end=None, mod_revision=None, retry=None):
+        fields = build_range_request(key, range_end)
+        if mod_revision is None:
+            return self.call_rpc('/kv/deleterange', fields, retry)
+        compare = {'target': 'MOD', 'mod_revision': mod_revision, 'key': fields['key']}
+        return self.txn(compare, {'request_delete_range': fields}, retry)
+
+    def deleteprefix(self, key, retry=None):
+        return self.deleterange(key, prefix_range_end(key), retry=retry)
+
+    def watchrange(self, key, range_end=None, start_revision=None, filters=None):
+        """returns: response object"""
+        params = build_range_request(key, range_end)
+        if start_revision is not None:
+            params['start_revision'] = start_revision
+        params['filters'] = filters or []
+        kwargs = self._prepare_common_parameters(1, self.read_timeout)
+        request_executor = self._prepare_request(kwargs, {'create_request': params})
+        kwargs.update(timeout=urllib3.Timeout(connect=kwargs['timeout']), retries=0)
+        return request_executor(self._MPOST, self._base_uri + self.version_prefix + '/watch', **kwargs)
+
+    def watchprefix(self, key, start_revision=None, filters=None):
+        return self.watchrange(key, prefix_range_end(key), start_revision, filters)
+
+
+class KVCache(Thread):
+
+    def __init__(self, dcs, client):
+        Thread.__init__(self)
+        self.daemon = True
+        self._dcs = dcs
+        self._client = client
+        self.condition = Condition()
+        self._config_key = base64_encode(dcs.config_path)
+        self._leader_key = base64_encode(dcs.leader_path)
+        self._optime_key = base64_encode(dcs.leader_optime_path)
+        self._status_key = base64_encode(dcs.status_path)
+        self._name = base64_encode(dcs._name)
+        self._is_ready = False
+        self._response = None
+        self._response_lock = Lock()
+        self._object_cache = {}
+        self._object_cache_lock = Lock()
+        self.start()
+
+    def set(self, value, overwrite=False):
+        with self._object_cache_lock:
+            name = value['key']
+            old_value = self._object_cache.get(name)
+            ret = not old_value or int(old_value['mod_revision']) < int(value['mod_revision'])
+            if ret or overwrite and old_value['mod_revision'] == value['mod_revision']:
+                self._object_cache[name] = value
+        return ret, old_value
+
+    def delete(self, name, mod_revision):
+        with self._object_cache_lock:
+            old_value = self._object_cache.get(name)
+            ret = old_value and int(old_value['mod_revision']) < int(mod_revision)
+            if ret:
+                del self._object_cache[name]
+        return not old_value or ret, old_value
+
+    def copy(self):
+        with self._object_cache_lock:
+            return [v.copy() for v in self._object_cache.values()]
+
+    def get(self, name):
+        with self._object_cache_lock:
+            return self._object_cache.get(name)
+
+    def _process_event(self, event):
+        kv = event['kv']
+        key = kv['key']
+        if event.get('type') == 'DELETE':
+            success, old_value = self.delete(key, kv['mod_revision'])
+        else:
+            success, old_value = self.set(kv, True)
+
+        if success:
+            old_value = old_value and old_value.get('value')
+            new_value = kv.get('value')
+
+            value_changed = old_value != new_value and \
+                (key == self._leader_key or key in (self._optime_key, self._status_key) and new_value is not None or
+                 key == self._config_key and old_value is not None and new_value is not None)
+
+            if value_changed:
+                logger.debug('%s changed from %s to %s', key, old_value, new_value)
+
+            # We also want to wake up HA loop on replicas if leader optime (or status key) was updated
+            if value_changed and (key not in (self._optime_key, self._status_key) or
+                                  (self.get(self._leader_key) or {}).get('value') != self._name):
+                self._dcs.event.set()
+
+    def _process_message(self, message):
+        logger.debug('Received message: %s', message)
+        if 'error' in message:
+            _raise_for_data(message)
+        for event in message.get('result', {}).get('events', []):
+            self._process_event(event)
+
+    @staticmethod
+    def _finish_response(response):
+        try:
+            response.close()
+        finally:
+            response.release_conn()
+
+    def _do_watch(self, revision):
+        with self._response_lock:
+            self._response = None
+        response = self._client.watchprefix(self._dcs.cluster_prefix, revision)
+        with self._response_lock:
+            if self._response is None:
+                self._response = response
+
+        if not self._response:
+            return self._finish_response(response)
+
+        for message in iter_response_objects(response):
+            self._process_message(message)
+
+    def _build_cache(self):
+        result = self._dcs.retry(self._client.prefix, self._dcs.cluster_prefix)
+        with self._object_cache_lock:
+            self._object_cache = {node['key']: node for node in result.get('kvs', [])}
+        with self.condition:
+            self._is_ready = True
+            self.condition.notify()
+
+        try:
+            self._do_watch(result['header']['revision'])
+        except Exception as e:
+            logger.error('watchprefix failed: %r', e)
+        finally:
+            with self.condition:
+                self._is_ready = False
+            with self._response_lock:
+                response, self._response = self._response, None
+            if response:
+                self._finish_response(response)
+
+    def run(self):
+        while True:
+            try:
+                self._build_cache()
+            except Exception as e:
+                logger.error('KVCache.run %r', e)
+                time.sleep(1)
+
+    def kill_stream(self):
+        sock = None
+        with self._response_lock:
+            if self._response:
+                try:
+                    sock = self._response.connection.sock
+                except Exception:
+                    sock = None
+            else:
+                self._response = False
+        if sock:
+            try:
+                sock.shutdown(socket.SHUT_RDWR)
+                sock.close()
+            except Exception as e:
+                logger.debug('Error on socket.shutdown: %r', e)
+
+    def is_ready(self):
+        """Must be called only when holding the lock on `condition`"""
+        return self._is_ready
+
+
+class PatroniEtcd3Client(Etcd3Client):
+
+    def __init__(self, *args, **kwargs):
+        self._kv_cache = None
+        super(PatroniEtcd3Client, self).__init__(*args, **kwargs)
+
+    def configure(self, etcd3):
+        self._etcd3 = etcd3
+
+    def start_watcher(self):
+        if self._cluster_version >= (3, 1):
+            self._kv_cache = KVCache(self._etcd3, self)
+
+    def _restart_watcher(self):
+        if self._kv_cache:
+            self._kv_cache.kill_stream()
+
+    def set_base_uri(self, value):
+        super(PatroniEtcd3Client, self).set_base_uri(value)
+        self._restart_watcher()
+
+    def authenticate(self):
+        ret = super(PatroniEtcd3Client, self).authenticate()
+        if ret:
+            self._restart_watcher()
+        return ret
+
+    def _wait_cache(self, timeout):
+        stop_time = time.time() + timeout
+        while not self._kv_cache.is_ready():
+            timeout = stop_time - time.time()
+            if timeout <= 0:
+                raise RetryFailedError('Exceeded retry deadline')
+            self._kv_cache.condition.wait(timeout)
+
+    def get_cluster(self):
+        if self._kv_cache:
+            with self._kv_cache.condition:
+                self._wait_cache(self._etcd3._retry.deadline)
+                return self._kv_cache.copy()
+        else:
+            return self._etcd3.retry(self.prefix, self._etcd3.cluster_prefix).get('kvs', [])
+
+    def call_rpc(self, method, fields, retry=None):
+        ret = super(PatroniEtcd3Client, self).call_rpc(method, fields, retry)
+
+        if self._kv_cache:
+            value = delete = None
+            if method == '/kv/txn' and ret.get('succeeded'):
+                on_success = fields['success'][0]
+                value = on_success.get('request_put')
+                delete = on_success.get('request_delete_range')
+            elif method == '/kv/put' and ret:
+                value = fields
+            elif method == '/kv/deleterange' and ret:
+                delete = fields
+
+            if value:
+                value['mod_revision'] = ret['header']['revision']
+                self._kv_cache.set(value)
+            elif delete and 'range_end' not in delete:
+                self._kv_cache.delete(delete['key'], ret['header']['revision'])
+
+        return ret
+
+
+class Etcd3(AbstractEtcd):
+
+    def __init__(self, config):
+        super(Etcd3, self).__init__(config, PatroniEtcd3Client, (DeadlineExceeded, Unavailable, FailedPrecondition))
+        self.__do_not_watch = False
+        self._lease = None
+        self._last_lease_refresh = 0
+
+        self._client.configure(self)
+        if not self._ctl:
+            self._client.start_watcher()
+            self.create_lease()
+
+    def set_socket_options(self, sock, socket_options):
+        enable_keepalive(sock, self.ttl, int(self.loop_wait + self._retry.deadline))
+
+    def set_ttl(self, ttl):
+        self.__do_not_watch = super(Etcd3, self).set_ttl(ttl)
+        if self.__do_not_watch:
+            self._lease = None
+
+    def _do_refresh_lease(self, retry=None):
+        if self._lease and self._last_lease_refresh + self._loop_wait > time.time():
+            return False
+
+        if self._lease and not self._client.lease_keepalive(self._lease, retry):
+            self._lease = None
+
+        ret = not self._lease
+        if ret:
+            self._lease = self._client.lease_grant(self._ttl, retry)
+
+        self._last_lease_refresh = time.time()
+        return ret
+
+    def refresh_lease(self):
+        try:
+            return self.retry(self._do_refresh_lease)
+        except (Etcd3ClientError, RetryFailedError):
+            logger.exception('refresh_lease')
+        raise Etcd3Error('Failed to keepalive/grant lease')
+
+    def create_lease(self):
+        while not self._lease:
+            try:
+                self.refresh_lease()
+            except Etcd3Error:
+                logger.info('waiting on etcd')
+                time.sleep(5)
+
+    @property
+    def cluster_prefix(self):
+        return self.client_path('')
+
+    @staticmethod
+    def member(node):
+        return Member.from_node(node['mod_revision'], os.path.basename(node['key']), node['lease'], node['value'])
+
+    def _load_cluster(self):
+        cluster = None
+        try:
+            path_len = len(self.cluster_prefix)
+
+            nodes = {}
+            for node in self._client.get_cluster():
+                node['key'] = base64_decode(node['key'])
+                node['value'] = base64_decode(node.get('value', ''))
+                node['lease'] = node.get('lease')
+                nodes[node['key'][path_len:].lstrip('/')] = node
+
+            # get initialize flag
+            initialize = nodes.get(self._INITIALIZE)
+            initialize = initialize and initialize['value']
+
+            # get global dynamic configuration
+            config = nodes.get(self._CONFIG)
+            config = config and ClusterConfig.from_node(config['mod_revision'], config['value'])
+
+            # get timeline history
+            history = nodes.get(self._HISTORY)
+            history = history and TimelineHistory.from_node(history['mod_revision'], history['value'])
+
+            # get last know leader lsn and slots
+            status = nodes.get(self._STATUS)
+            if status:
+                try:
+                    status = json.loads(status['value'])
+                    last_lsn = status.get(self._OPTIME)
+                    slots = status.get('slots')
+                except Exception:
+                    slots = last_lsn = None
+            else:
+                last_lsn = nodes.get(self._LEADER_OPTIME)
+                last_lsn = last_lsn and last_lsn['value']
+                slots = None
+
+            try:
+                last_lsn = int(last_lsn)
+            except Exception:
+                last_lsn = 0
+
+            # get list of members
+            members = [self.member(n) for k, n in nodes.items() if k.startswith(self._MEMBERS) and k.count('/') == 1]
+
+            # get leader
+            leader = nodes.get(self._LEADER)
+            if not self._ctl and leader and leader['value'] == self._name and self._lease != leader.get('lease'):
+                logger.warning('I am the leader but not owner of the lease')
+
+            if leader:
+                member = Member(-1, leader['value'], None, {})
+                member = ([m for m in members if m.name == leader['value']] or [member])[0]
+                leader = Leader(leader['mod_revision'], leader['lease'], member)
+
+            # failover key
+            failover = nodes.get(self._FAILOVER)
+            if failover:
+                failover = Failover.from_node(failover['mod_revision'], failover['value'])
+
+            # get synchronization state
+            sync = nodes.get(self._SYNC)
+            sync = SyncState.from_node(sync and sync['mod_revision'], sync and sync['value'])
+
+            cluster = Cluster(initialize, config, leader, last_lsn, members, failover, sync, history, slots)
+        except UnsupportedEtcdVersion:
+            raise
+        except Exception as e:
+            self._handle_exception(e, 'get_cluster', raise_ex=Etcd3Error('Etcd is not responding properly'))
+        self._has_failed = False
+        return cluster
+
+    @catch_etcd_errors
+    def touch_member(self, data, permanent=False):
+        if not permanent:
+            try:
+                self.refresh_lease()
+            except Etcd3Error:
+                return False
+
+        cluster = self.cluster
+        member = cluster and cluster.get_member(self._name, fallback_to_leader=False)
+
+        if member and member.session == self._lease and deep_compare(data, member.data):
+            return True
+
+        data = json.dumps(data, separators=(',', ':'))
+        try:
+            return self._client.put(self.member_path, data, None if permanent else self._lease)
+        except LeaseNotFound:
+            self._lease = None
+            logger.error('Our lease disappeared from Etcd, can not "touch_member"')
+
+    @catch_etcd_errors
+    def take_leader(self):
+        return self.retry(self._client.put, self.leader_path, self._name, self._lease)
+
+    @catch_etcd_errors
+    def _do_attempt_to_acquire_leader(self, permanent):
+        try:
+            return self.retry(self._client.put, self.leader_path, self._name, None if permanent else self._lease, 0)
+        except LeaseNotFound:
+            self._lease = None
+            logger.error('Our lease disappeared from Etcd. Will try to get a new one and retry attempt')
+            self.refresh_lease()
+            return self.retry(self._client.put, self.leader_path, self._name, None if permanent else self._lease, 0)
+
+    def attempt_to_acquire_leader(self, permanent=False):
+        if not self._lease and not permanent:
+            self.refresh_lease()
+
+        ret = self._do_attempt_to_acquire_leader(permanent)
+        if not ret:
+            logger.info('Could not take out TTL lock')
+        return ret
+
+    @catch_etcd_errors
+    def set_failover_value(self, value, index=None):
+        return self._client.put(self.failover_path, value, mod_revision=index)
+
+    @catch_etcd_errors
+    def set_config_value(self, value, index=None):
+        return self._client.put(self.config_path, value, mod_revision=index)
+
+    @catch_etcd_errors
+    def _write_leader_optime(self, last_lsn):
+        return self._client.put(self.leader_optime_path, last_lsn)
+
+    @catch_etcd_errors
+    def _write_status(self, value):
+        return self._client.put(self.status_path, value)
+
+    @catch_etcd_errors
+    def _update_leader(self):
+        if not self._lease:
+            self.refresh_lease()
+        elif self.retry(self._client.lease_keepalive, self._lease):
+            self._last_lease_refresh = time.time()
+
+        if self._lease:
+            cluster = self.cluster
+            leader_lease = cluster and isinstance(cluster.leader, Leader) and cluster.leader.session
+            if leader_lease != self._lease:
+                self.take_leader()
+        return bool(self._lease)
+
+    @catch_etcd_errors
+    def initialize(self, create_new=True, sysid=""):
+        return self.retry(self._client.put, self.initialize_path, sysid, None, 0 if create_new else None)
+
+    @catch_etcd_errors
+    def _delete_leader(self):
+        cluster = self.cluster
+        if cluster and isinstance(cluster.leader, Leader) and cluster.leader.name == self._name:
+            return self._client.deleterange(self.leader_path, mod_revision=cluster.leader.index)
+
+    @catch_etcd_errors
+    def cancel_initialization(self):
+        return self.retry(self._client.deleterange, self.initialize_path)
+
+    @catch_etcd_errors
+    def delete_cluster(self):
+        return self.retry(self._client.deleteprefix, self.cluster_prefix)
+
+    @catch_etcd_errors
+    def set_history_value(self, value):
+        return self._client.put(self.history_path, value)
+
+    @catch_etcd_errors
+    def set_sync_state_value(self, value, index=None):
+        return self.retry(self._client.put, self.sync_path, value, mod_revision=index)
+
+    @catch_etcd_errors
+    def delete_sync_state(self, index=None):
+        return self.retry(self._client.deleterange, self.sync_path, mod_revision=index)
+
+    def watch(self, leader_index, timeout):
+        if self.__do_not_watch:
+            self.__do_not_watch = False
+            return True
+
+        try:
+            return super(Etcd3, self).watch(None, timeout)
+        finally:
+            self.event.clear()

patroni/dcs/kubernetes.py

@@ -1,13 +1,16 @@
-from __future__ import absolute_import
 import datetime
 import functools
 import json
 import logging
+import os
+import random
 import socket
+import six
 import sys
 import time
+import urllib3
+import yaml
 
-from kubernetes import client as k8s_client, config as k8s_config, watch as k8s_watch
 from urllib3 import Timeout
 from urllib3.exceptions import HTTPError
 from six.moves.http_client import HTTPException
@@ -15,15 +18,412 @@ from threading import Condition, Lock, Thread
 
 from . import AbstractDCS, Cluster, ClusterConfig, Failover, Leader, Member, SyncState, TimelineHistory
 from ..exceptions import DCSError
-from ..utils import deep_compare, Retry, RetryFailedError, tzutc, USER_AGENT
+from ..utils import deep_compare, iter_response_objects, keepalive_socket_options,\
+        Retry, RetryFailedError, tzutc, uri, USER_AGENT
 
 logger = logging.getLogger(__name__)
 
+KUBE_CONFIG_DEFAULT_LOCATION = os.environ.get('KUBECONFIG', '~/.kube/config')
+SERVICE_HOST_ENV_NAME = 'KUBERNETES_SERVICE_HOST'
+SERVICE_PORT_ENV_NAME = 'KUBERNETES_SERVICE_PORT'
+SERVICE_TOKEN_FILENAME = '/var/run/secrets/kubernetes.io/serviceaccount/token'
+SERVICE_CERT_FILENAME = '/var/run/secrets/kubernetes.io/serviceaccount/ca.crt'
+
 
 class KubernetesError(DCSError):
     pass
 
 
+# this function does the same mapping of snake_case => camelCase for > 97% of cases as autogenerated swagger code
+def to_camel_case(value):
+    reserved = {'api', 'apiv3', 'cidr', 'cpu', 'csi', 'id', 'io', 'ip', 'ipc', 'pid', 'tls', 'uri', 'url', 'uuid'}
+    words = value.split('_')
+    return words[0] + ''.join(w.upper() if w in reserved else w.title() for w in words[1:])
+
+
+class K8sConfig(object):
+
+    class ConfigException(Exception):
+        pass
+
+    def __init__(self):
+        self.pool_config = {'maxsize': 10, 'num_pools': 10}  # configuration for urllib3.PoolManager
+        self._make_headers()
+
+    def _make_headers(self, token=None, **kwargs):
+        self._headers = urllib3.make_headers(user_agent=USER_AGENT, **kwargs)
+        if token:
+            self._headers['authorization'] = 'Bearer ' + token
+
+    def load_incluster_config(self, ca_certs=SERVICE_CERT_FILENAME):
+        if SERVICE_HOST_ENV_NAME not in os.environ or SERVICE_PORT_ENV_NAME not in os.environ:
+            raise self.ConfigException('Service host/port is not set.')
+        if not os.environ[SERVICE_HOST_ENV_NAME] or not os.environ[SERVICE_PORT_ENV_NAME]:
+            raise self.ConfigException('Service host/port is set but empty.')
+
+        if not os.path.isfile(ca_certs):
+            raise self.ConfigException('Service certificate file does not exists.')
+        with open(ca_certs) as f:
+            if not f.read():
+                raise self.ConfigException('Cert file exists but empty.')
+        self.pool_config['ca_certs'] = ca_certs
+
+        if not os.path.isfile(SERVICE_TOKEN_FILENAME):
+            raise self.ConfigException('Service token file does not exists.')
+        with open(SERVICE_TOKEN_FILENAME) as f:
+            token = f.read()
+            if not token:
+                raise self.ConfigException('Token file exists but empty.')
+            self._make_headers(token=token)
+        self._server = uri('https', (os.environ[SERVICE_HOST_ENV_NAME], os.environ[SERVICE_PORT_ENV_NAME]))
+
+    @staticmethod
+    def _get_by_name(config, section, name):
+        for c in config[section + 's']:
+            if c['name'] == name:
+                return c[section]
+
+    def load_kube_config(self, context=None):
+        with open(os.path.expanduser(KUBE_CONFIG_DEFAULT_LOCATION)) as f:
+            config = yaml.safe_load(f)
+
+        context = self._get_by_name(config, 'context', context or config['current-context'])
+        cluster = self._get_by_name(config, 'cluster', context['cluster'])
+        user = self._get_by_name(config, 'user', context['user'])
+
+        self._server = cluster['server'].rstrip('/')
+        if self._server.startswith('https'):
+            self.pool_config.update({v: user[k] for k, v in {'client-certificate': 'cert_file',
+                                                             'client-key': 'key_file'}.items() if k in user})
+            if 'certificate-authority' in cluster:
+                self.pool_config['ca_certs'] = cluster['certificate-authority']
+            self.pool_config['cert_reqs'] = 'CERT_NONE' if cluster.get('insecure-skip-tls-verify') else 'CERT_REQUIRED'
+        if user.get('token'):
+            self._make_headers(token=user['token'])
+        elif 'username' in user and 'password' in user:
+            self._headers = self._make_headers(basic_auth=':'.join((user['username'],  user['password'])))
+
+    @property
+    def server(self):
+        return self._server
+
+    @property
+    def headers(self):
+        return self._headers.copy()
+
+
+class K8sObject(object):
+
+    def __init__(self, kwargs):
+        self._dict = {k: self._wrap(k, v) for k, v in kwargs.items()}
+
+    def get(self, name, default=None):
+        return self._dict.get(name, default)
+
+    def __getattr__(self, name):
+        return self.get(to_camel_case(name))
+
+    @classmethod
+    def _wrap(cls, parent, value):
+        if isinstance(value, dict):
+            # we know that `annotations` and `labels` are dicts and therefore don't want to convert them into K8sObject
+            return value if parent in {'annotations', 'labels'} and \
+                    all(isinstance(v, six.string_types) for v in value.values()) else cls(value)
+        elif isinstance(value, list):
+            return [cls._wrap(None, v) for v in value]
+        else:
+            return value
+
+    def to_dict(self):
+        return self._dict
+
+    def __repr__(self):
+        return json.dumps(self, indent=4, default=lambda o: o.to_dict())
+
+
+class K8sException(Exception):
+    pass
+
+
+class K8sConnectionFailed(K8sException):
+    pass
+
+
+class K8sClient(object):
+
+    class rest(object):
+
+        class ApiException(Exception):
+            def __init__(self, status=None, reason=None, http_resp=None):
+                self.status = http_resp.status if http_resp else status
+                self.reason = http_resp.reason if http_resp else reason
+                self.body = http_resp.data if http_resp else None
+                self.headers = http_resp.getheaders() if http_resp else None
+
+            def __str__(self):
+                error_message = "({0})\nReason: {1}\n".format(self.status, self.reason)
+                if self.headers:
+                    error_message += "HTTP response headers: {0}\n".format(self.headers)
+                if self.body:
+                    error_message += "HTTP response body: {0}\n".format(self.body)
+                return error_message
+
+    class ApiClient(object):
+
+        _API_URL_PREFIX = '/api/v1/namespaces/'
+
+        def __init__(self, bypass_api_service=False):
+            self._bypass_api_service = bypass_api_service
+            self.pool_manager = urllib3.PoolManager(**k8s_config.pool_config)
+            self._base_uri = k8s_config.server
+            self._api_servers_cache = [k8s_config.server]
+            self._api_servers_cache_updated = 0
+            self.set_api_servers_cache_ttl(10)
+            self.set_read_timeout(10)
+            try:
+                self._load_api_servers_cache()
+            except K8sException:
+                pass
+
+        def set_read_timeout(self, timeout):
+            self._read_timeout = timeout
+
+        def set_api_servers_cache_ttl(self, ttl):
+            self._api_servers_cache_ttl = ttl - 0.5
+
+        def set_base_uri(self, value):
+            logger.info('Selected new K8s API server endpoint %s', value)
+            # We will connect by IP of the master node which is not listed as alternative name
+            self.pool_manager.connection_pool_kw['assert_hostname'] = False
+            self._base_uri = value
+
+        @staticmethod
+        def _handle_server_response(response, _preload_content):
+            if response.status not in range(200, 206):
+                raise k8s_client.rest.ApiException(http_resp=response)
+            return K8sObject(json.loads(response.data.decode('utf-8'))) if _preload_content else response
+
+        @staticmethod
+        def _make_headers(headers):
+            ret = k8s_config.headers
+            ret.update(headers or {})
+            return ret
+
+        @property
+        def api_servers_cache(self):
+            base_uri, cache = self._base_uri, self._api_servers_cache
+            return ([base_uri] if base_uri in cache else []) + [machine for machine in cache if machine != base_uri]
+
+        def _get_api_servers(self, api_servers_cache):
+            _, per_node_timeout, per_node_retries = self._calculate_timeouts(len(api_servers_cache))
+            kwargs = {'headers': self._make_headers({}), 'preload_content': True, 'retries': per_node_retries,
+                      'timeout': urllib3.Timeout(connect=max(1, per_node_timeout/2.0), total=per_node_timeout)}
+            path = self._API_URL_PREFIX + 'default/endpoints/kubernetes'
+            for base_uri in api_servers_cache:
+                try:
+                    response = self.pool_manager.request('GET', base_uri + path, **kwargs)
+                    endpoint = self._handle_server_response(response, True)
+                    for subset in endpoint.subsets:
+                        for port in subset.ports:
+                            if port.name == 'https' and port.protocol == 'TCP':
+                                addresses = [uri('https', (a.ip, port.port)) for a in subset.addresses]
+                                if addresses:
+                                    random.shuffle(addresses)
+                                    return addresses
+                except Exception as e:
+                    if isinstance(e, k8s_client.rest.ApiException) and e.status == 403:
+                        raise
+                    self.pool_manager.clear()
+                    logger.error('Failed to get "kubernetes" endpoint from %s: %r', base_uri, e)
+            raise K8sConnectionFailed('No more K8s API server nodes in the cluster')
+
+        def _refresh_api_servers_cache(self, updating_cache=False):
+            if self._bypass_api_service:
+                try:
+                    api_servers_cache = [k8s_config.server] if updating_cache else self.api_servers_cache
+                    self._api_servers_cache = self._get_api_servers(api_servers_cache)
+                    if updating_cache:
+                        self.pool_manager.clear()
+                except k8s_client.rest.ApiException:  # 403 Permission denied
+                    logger.warning("Kubernetes RBAC doesn't allow GET access to the 'kubernetes' "
+                                   "endpoint in the 'default' namespace. Disabling 'bypass_api_service'.")
+                    self._bypass_api_service = False
+                    self._api_servers_cache = [k8s_config.server]
+                    if not updating_cache:
+                        self.pool_manager.clear()
+                except K8sConnectionFailed:
+                    if updating_cache:
+                        raise K8sException("Could not get the list of K8s API server nodes")
+                    return
+            else:
+                self._api_servers_cache = [k8s_config.server]
+
+            if self._base_uri not in self._api_servers_cache:
+                self.set_base_uri(self._api_servers_cache[0])
+            self._api_servers_cache_updated = time.time()
+
+        def refresh_api_servers_cache(self):
+            if self._bypass_api_service and time.time() - self._api_servers_cache_updated > self._api_servers_cache_ttl:
+                self._refresh_api_servers_cache()
+
+        def _load_api_servers_cache(self):
+            self._update_api_servers_cache = True
+            self._refresh_api_servers_cache(True)
+            self._update_api_servers_cache = False
+
+        def _calculate_timeouts(self, api_servers, timeout=None):
+            """Calculate a request timeout and number of retries per single K8s API server node.
+            In case if the timeout per node is too small (less than one second) we will reduce the number of nodes.
+            For the cluster with only one API server node we will try to do 1 retry.
+            No retries for clusters with 2 or more API server nodes. We better rely on switching to a different node."""
+
+            per_node_timeout = timeout = float(timeout or self._read_timeout)
+
+            max_retries = 3 - min(api_servers, 2)
+            per_node_retries = 1
+            min_timeout = 1.0
+
+            while api_servers > 0:
+                per_node_timeout = float(timeout) / api_servers
+                if per_node_timeout >= min_timeout:
+                    # for small clusters we will try to do more than one try on every node
+                    while per_node_retries < max_retries and per_node_timeout / (per_node_retries + 1) >= min_timeout:
+                        per_node_retries += 1
+                    per_node_timeout /= per_node_retries
+                    break
+                # if the timeout per one node is to small try to reduce number of nodes
+                api_servers -= 1
+                max_retries = 1
+
+            return api_servers, per_node_timeout, per_node_retries - 1
+
+        def _do_http_request(self, retry, api_servers_cache, method, path, **kwargs):
+            some_request_failed = False
+            for i, base_uri in enumerate(api_servers_cache):
+                if i > 0:
+                    logger.info('Retrying on %s', base_uri)
+                try:
+                    response = self.pool_manager.request(method, base_uri + path, **kwargs)
+                    if some_request_failed:
+                        self.set_base_uri(base_uri)
+                        self._refresh_api_servers_cache()
+                    return response
+                except (HTTPError, HTTPException, socket.error, socket.timeout) as e:
+                    self.pool_manager.clear()
+                    if not retry:
+                        # switch to the next node if request failed and retry is not allowed
+                        if i + 1 < len(api_servers_cache):
+                            self.set_base_uri(api_servers_cache[i + 1])
+                        raise K8sException('{0} {1} request failed'.format(method, path))
+                    logger.error('Request to server %s failed: %r', base_uri, e)
+                    some_request_failed = True
+
+            raise K8sConnectionFailed('No more API server nodes in the cluster')
+
+        def request(self, retry, method, path, timeout=None, **kwargs):
+            if self._update_api_servers_cache:
+                self._load_api_servers_cache()
+
+            api_servers_cache = self.api_servers_cache
+            api_servers = len(api_servers_cache)
+
+            if timeout:
+                if isinstance(timeout, six.integer_types + (float,)):
+                    timeout = urllib3.Timeout(total=timeout)
+                elif isinstance(timeout, tuple) and len(timeout) == 2:
+                    timeout = urllib3.Timeout(connect=timeout[0], read=timeout[1])
+                retries = 0
+            else:
+                _, timeout, retries = self._calculate_timeouts(api_servers)
+                timeout = urllib3.Timeout(connect=max(1, timeout/2.0), total=timeout)
+            kwargs.update(retries=retries, timeout=timeout)
+
+            while True:
+                try:
+                    return self._do_http_request(retry, api_servers_cache, method, path, **kwargs)
+                except K8sConnectionFailed as ex:
+                    try:
+                        self._load_api_servers_cache()
+                        api_servers_cache = self.api_servers_cache
+                        api_servers = len(api_servers_cache)
+                    except Exception as e:
+                        logger.debug('Failed to update list of K8s master nodes: %r', e)
+
+                    sleeptime = retry.sleeptime
+                    remaining_time = (retry.stoptime or time.time()) - sleeptime - time.time()
+                    nodes, timeout, retries = self._calculate_timeouts(api_servers, remaining_time)
+                    if nodes == 0:
+                        self._update_api_servers_cache = True
+                        raise ex
+                    retry.sleep_func(sleeptime)
+                    retry.update_delay()
+                    # We still have some time left. Partially reduce `api_servers_cache` and retry request
+                    kwargs.update(timeout=urllib3.Timeout(connect=max(1, timeout/2.0), total=timeout), retries=retries)
+                    api_servers_cache = api_servers_cache[:nodes]
+
+        def call_api(self, method, path, headers=None, body=None, _retry=None,
+                     _preload_content=True, _request_timeout=None, **kwargs):
+            headers = self._make_headers(headers)
+            fields = {to_camel_case(k): v for k, v in kwargs.items()}  # resource_version => resourceVersion
+            body = json.dumps(body, default=lambda o: o.to_dict()) if body is not None else None
+
+            response = self.request(_retry, method, self._API_URL_PREFIX + path, headers=headers, fields=fields,
+                                    body=body, preload_content=_preload_content, timeout=_request_timeout)
+
+            return self._handle_server_response(response, _preload_content)
+
+    class CoreV1Api(object):
+
+        def __init__(self, api_client=None):
+            self._api_client = api_client or k8s_client.ApiClient()
+
+        def __getattr__(self, func):  # `func` name pattern: (action)_namespaced_(kind)
+            action, kind = func.split('_namespaced_')  # (read|list|create|patch|replace|delete|delete_collection)
+            kind = kind.replace('_', '') + ('s' * int(kind[-1] != 's'))  # plural, single word
+
+            def wrapper(*args, **kwargs):
+                method = {'read': 'GET', 'list': 'GET', 'create': 'POST',
+                          'replace': 'PUT'}.get(action, action.split('_')[0]).upper()
+
+                if action == 'create' or len(args) == 1:  # namespace is a first argument and name in not in arguments
+                    path = '/'.join([args[0], kind])
+                else:  # name, namespace followed by optional body
+                    path = '/'.join([args[1], kind, args[0]])
+
+                headers = {'Content-Type': 'application/strategic-merge-patch+json'} if action == 'patch' else {}
+
+                if len(args) == 3:  # name, namespace, body
+                    body = args[2]
+                elif action == 'create':  # namespace, body
+                    body = args[1]
+                elif action == 'delete':  # name, namespace
+                    body = kwargs.pop('body', None)
+                else:
+                    body = None
+
+                return self._api_client.call_api(method, path, headers, body, **kwargs)
+            return wrapper
+
+    class _K8sObjectTemplate(K8sObject):
+        """The template for objects which we create locally, e.g. k8s_client.V1ObjectMeta & co"""
+        def __init__(self, **kwargs):
+            self._dict = {to_camel_case(k): v for k, v in kwargs.items()}
+
+    def __init__(self):
+        self.__cls_cache = {}
+        self.__cls_lock = Lock()
+
+    def __getattr__(self, name):
+        with self.__cls_lock:
+            if name not in self.__cls_cache:
+                self.__cls_cache[name] = type(name, (self._K8sObjectTemplate,), {})
+        return self.__cls_cache[name]
+
+
+k8s_client = K8sClient()
+k8s_config = K8sConfig()
+
+
 class KubernetesRetriableException(k8s_client.rest.ApiException):
 
     def __init__(self, orig):
@@ -41,45 +441,41 @@ class KubernetesRetriableException(k8s_client.rest.ApiException):
 
 class CoreV1ApiProxy(object):
 
-    def __init__(self, use_endpoints=False):
-        self._api = k8s_client.CoreV1Api()
-        self._api.api_client.user_agent = USER_AGENT
-        self._api.api_client.rest_client.pool_manager.connection_pool_kw['maxsize'] = 10
-        self._request_timeout = None
-        self._use_endpoints = use_endpoints
+    def __init__(self, use_endpoints=False, bypass_api_service=False):
+        self._api_client = k8s_client.ApiClient(bypass_api_service)
+        self._core_v1_api = k8s_client.CoreV1Api(self._api_client)
+        self._use_endpoints = bool(use_endpoints)
 
     def configure_timeouts(self, loop_wait, retry_timeout, ttl):
         # Normally every loop_wait seconds we should have receive something from the socket.
         # If we didn't received anything after the loop_wait + retry_timeout it is a time
         # to start worrying (send keepalive messages). Finally, the connection should be
         # considered as dead if we received nothing from the socket after the ttl seconds.
-        cnt = 3
-        idle = int(loop_wait + retry_timeout)
-        intvl = max(1, int(float(ttl - idle) / cnt))
-        self._api.api_client.rest_client.pool_manager.connection_pool_kw['socket_options'] = [
-            (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1),
-            (socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, idle),
-            (socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, intvl),
-            (socket.IPPROTO_TCP, socket.TCP_KEEPCNT, cnt),
-            (socket.IPPROTO_TCP, 18, int(ttl * 1000))  # TCP_USER_TIMEOUT
-        ]
-        self._request_timeout = (1, retry_timeout / 3.0)
+        self._api_client.pool_manager.connection_pool_kw['socket_options'] = \
+                list(keepalive_socket_options(ttl, int(loop_wait + retry_timeout)))
+        self._api_client.set_read_timeout(retry_timeout)
+        self._api_client.set_api_servers_cache_ttl(loop_wait)
+
+    def refresh_api_servers_cache(self):
+        self._api_client.refresh_api_servers_cache()
 
     def __getattr__(self, func):
         if func.endswith('_kind'):
             func = func[:-4] + ('endpoints' if self._use_endpoints else 'config_map')
 
         def wrapper(*args, **kwargs):
-            if '_request_timeout' not in kwargs:
-                kwargs['_request_timeout'] = self._request_timeout
             try:
-                return getattr(self._api, func)(*args, **kwargs)
+                return getattr(self._core_v1_api, func)(*args, **kwargs)
             except k8s_client.rest.ApiException as e:
-                if e.status in (502, 503, 504) or e.headers and 'retry-after' in e.headers:  # XXX
+                if e.status in (500, 503, 504) or e.headers and 'retry-after' in e.headers:  # XXX
                     raise KubernetesRetriableException(e)
                 raise
         return wrapper
 
+    @property
+    def use_endpoints(self):
+        return self._use_endpoints
+
 
 def catch_kubernetes_errors(func):
     def wrapper(*args, **kwargs):
@@ -91,21 +487,21 @@ def catch_kubernetes_errors(func):
             elif e.status != 409:  # Object exists or conflict in resource_version
                 logger.exception('Unexpected error from Kubernetes API')
             return False
-        except (RetryFailedError, HTTPException, HTTPError, socket.error, socket.timeout):
+        except (RetryFailedError, K8sException):
             return False
     return wrapper
 
 
 class ObjectCache(Thread):
 
-    def __init__(self, dcs, func, retry, condition):
+    def __init__(self, dcs, func, retry, condition, name=None):
         Thread.__init__(self)
         self.daemon = True
-        self._api_client = k8s_client.ApiClient()
         self._dcs = dcs
         self._func = func
         self._retry = retry
         self._condition = condition
+        self._name = name  # name of this pod
         self._is_ready = False
         self._object_cache = {}
         self._object_cache_lock = Lock()
@@ -114,7 +510,7 @@ class ObjectCache(Thread):
 
     def _list(self):
         try:
-            return self._func(_request_timeout=(self._retry.deadline, Timeout.DEFAULT_TIMEOUT))
+            return self._func(_retry=self._retry.copy())
         except Exception:
             time.sleep(1)
             raise
@@ -143,6 +539,10 @@ class ObjectCache(Thread):
         with self._object_cache_lock:
             return self._object_cache.copy()
 
+    def get(self, name):
+        with self._object_cache_lock:
+            return self._object_cache.get(name)
+
     def _build_cache(self):
         objects = self._list()
         return_type = 'V1' + objects.kind[:-4]
@@ -154,8 +554,7 @@ class ObjectCache(Thread):
 
         response = self._watch(objects.metadata.resource_version)
         try:
-            for line in k8s_watch.watch.iter_resp_lines(response):
-                event = json.loads(line)
+            for event in iter_response_objects(response):
                 obj = event['object']
                 if obj.get('code') == 410:
                     break
@@ -164,8 +563,7 @@ class ObjectCache(Thread):
                 name = obj['metadata']['name']
 
                 if ev_type in ('ADDED', 'MODIFIED'):
-                    obj = k8s_watch.watch.SimpleNamespace(data=json.dumps(obj))
-                    obj = self._api_client.deserialize(obj, return_type)
+                    obj = K8sObject(obj)
                     success, old_value = self.set(name, obj)
                     if success:
                         new_value = (obj.metadata.annotations or {}).get(self._annotations_map.get(name))
@@ -180,9 +578,14 @@ class ObjectCache(Thread):
                     if old_value:
                         old_value = (old_value.metadata.annotations or {}).get(self._annotations_map.get(name))
 
-                    if old_value != new_value and \
-                            (name != self._dcs.config_path or old_value is not None and new_value is not None):
+                    value_changed = old_value != new_value and \
+                        (name != self._dcs.config_path or old_value is not None and new_value is not None)
+
+                    if value_changed:
                         logger.debug('%s changed from %s to %s', name, old_value, new_value)
+
+                    # Do not wake up HA loop if we run as leader and received leader object update event
+                    if value_changed or name == self._dcs.leader_path and self._name != new_value:
                         self._dcs.event.set()
         finally:
             with self._condition:
@@ -212,35 +615,33 @@ class Kubernetes(AbstractDCS):
         self._label_selector = ','.join('{0}={1}'.format(k, v) for k, v in self._labels.items())
         self._namespace = config.get('namespace') or 'default'
         self._role_label = config.get('role_label', 'role')
+        self._ca_certs = os.environ.get('PATRONI_KUBERNETES_CACERT', config.get('cacert')) or SERVICE_CERT_FILENAME
         config['namespace'] = ''
         super(Kubernetes, self).__init__(config)
         self._retry = Retry(deadline=config['retry_timeout'], max_delay=1, max_tries=-1,
-                            retry_exceptions=(KubernetesRetriableException, HTTPException,
-                                              HTTPError, socket.error, socket.timeout))
+                            retry_exceptions=KubernetesRetriableException)
         self._ttl = None
         try:
-            k8s_config.load_incluster_config()
+            k8s_config.load_incluster_config(ca_certs=self._ca_certs)
         except k8s_config.ConfigException:
             k8s_config.load_kube_config(context=config.get('context', 'local'))
 
-        self.__subsets = None
-        use_endpoints = config.get('use_endpoints') and (config.get('patronictl') or 'pod_ip' in config)
-        if use_endpoints:
-            addresses = [k8s_client.V1EndpointAddress(ip='127.0.0.1' if config.get('patronictl') else config['pod_ip'])]
-            ports = []
-            for p in config.get('ports', [{}]):
-                port = {'port': int(p.get('port', '5432'))}
-                port.update({n: p[n] for n in ('name', 'protocol') if p.get(n)})
-                ports.append(k8s_client.V1EndpointPort(**port))
-            self.__subsets = [k8s_client.V1EndpointSubset(addresses=addresses, ports=ports)]
-            self._should_create_config_service = True
-        self._api = CoreV1ApiProxy(use_endpoints)
+        self.__my_pod = None
+        self.__ips = [] if config.get('patronictl') else [config.get('pod_ip')]
+        self.__ports = []
+        for p in config.get('ports', [{}]):
+            port = {'port': int(p.get('port', '5432'))}
+            port.update({n: p[n] for n in ('name', 'protocol') if p.get(n)})
+            self.__ports.append(k8s_client.V1EndpointPort(**port))
+
+        bypass_api_service = not config.get('patronictl') and config.get('bypass_api_service')
+        self._api = CoreV1ApiProxy(config.get('use_endpoints'), bypass_api_service)
+        self._should_create_config_service = self._api.use_endpoints
         self.reload_config(config)
+        # leader_observed_record, leader_resource_version, and leader_observed_time are used only for leader race!
         self._leader_observed_record = {}
         self._leader_observed_time = None
         self._leader_resource_version = None
-        self._leader_observed_subsets = []
-        self._config_resource_version = None
         self.__do_not_watch = False
 
         self._condition = Condition()
@@ -251,17 +652,19 @@ class Kubernetes(AbstractDCS):
 
         kinds_func = functools.partial(self._api.list_namespaced_kind, self._namespace,
                                        label_selector=self._label_selector)
-        self._kinds = ObjectCache(self, kinds_func, self._retry, self._condition)
+        self._kinds = ObjectCache(self, kinds_func, self._retry, self._condition, self._name)
 
     def retry(self, *args, **kwargs):
-        return self._retry.copy()(*args, **kwargs)
+        retry = self._retry.copy()
+        kwargs['_retry'] = retry
+        return retry(*args, **kwargs)
 
     def client_path(self, path):
         return super(Kubernetes, self).client_path(path)[1:].replace('/', '-')
 
     @property
     def leader_path(self):
-        return self._base_path[1:] if self.__subsets else super(Kubernetes, self).leader_path
+        return self._base_path[1:] if self._api.use_endpoints else super(Kubernetes, self).leader_path
 
     def set_ttl(self, ttl):
         ttl = int(ttl)
@@ -286,8 +689,7 @@ class Kubernetes(AbstractDCS):
         member.data['pod_labels'] = pod.metadata.labels
         return member
 
-    def _wait_caches(self):
-        stop_time = time.time() + self._retry.deadline
+    def _wait_caches(self, stop_time):
         while not (self._pods.is_ready() and self._kinds.is_ready()):
             timeout = stop_time - time.time()
             if timeout <= 0:
@@ -295,16 +697,17 @@ class Kubernetes(AbstractDCS):
             self._condition.wait(timeout)
 
     def _load_cluster(self):
+        stop_time = time.time() + self._retry.deadline
+        self._api.refresh_api_servers_cache()
         try:
             with self._condition:
-                self._wait_caches()
+                self._wait_caches(stop_time)
 
                 members = [self.member(pod) for pod in self._pods.copy().values()]
                 nodes = self._kinds.copy()
 
             config = nodes.get(self.config_path)
             metadata = config and config.metadata
-            self._config_resource_version = metadata.resource_version if metadata else None
             annotations = metadata and metadata.annotations or {}
 
             # get initialize flag
@@ -322,12 +725,21 @@ class Kubernetes(AbstractDCS):
             leader = nodes.get(self.leader_path)
             metadata = leader and leader.metadata
             self._leader_resource_version = metadata.resource_version if metadata else None
-            self._leader_observed_subsets = leader.subsets if self.__subsets and leader and leader.subsets else []
             annotations = metadata and metadata.annotations or {}
 
-            # get last leader operation
-            last_leader_operation = annotations.get(self._OPTIME)
-            last_leader_operation = 0 if last_leader_operation is None else int(last_leader_operation)
+            # get last known leader lsn
+            last_lsn = annotations.get(self._OPTIME)
+            try:
+                last_lsn = 0 if last_lsn is None else int(last_lsn)
+            except Exception:
+                last_lsn = 0
+
+            # get permanent slots state (confirmed_flush_lsn)
+            slots = annotations.get('slots')
+            try:
+                slots = slots and json.loads(slots)
+            except Exception:
+                slots = None
 
             # get leader
             leader_record = {n: annotations.get(n) for n in (self._LEADER, 'acquireTime',
@@ -361,7 +773,7 @@ class Kubernetes(AbstractDCS):
             metadata = sync and sync.metadata
             sync = SyncState.from_node(metadata and metadata.resource_version,  metadata and metadata.annotations)
 
-            return Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+            return Cluster(initialize, config, leader, last_lsn, members, failover, sync, history, slots)
         except Exception:
             logger.exception('get_cluster')
             raise KubernetesError('Kubernetes API is not responding properly')
@@ -371,50 +783,71 @@ class Kubernetes(AbstractDCS):
         return p1.name == p2.name and p1.port == p2.port and (p1.protocol or 'TCP') == (p2.protocol or 'TCP')
 
     @staticmethod
-    def subsets_changed(last_observed_subsets, subsets):
+    def subsets_changed(last_observed_subsets, ip, ports):
         """
-        >>> Kubernetes.subsets_changed([], [])
-        False
-        >>> Kubernetes.subsets_changed([], [k8s_client.V1EndpointSubset()])
+        >>> Kubernetes.subsets_changed([], None, [])
         True
-        >>> s1 = [k8s_client.V1EndpointSubset(addresses=[k8s_client.V1EndpointAddress(ip='1.2.3.4')])]
-        >>> s2 = [k8s_client.V1EndpointSubset(addresses=[k8s_client.V1EndpointAddress(ip='1.2.3.5')])]
-        >>> Kubernetes.subsets_changed(s1, s2)
+        >>> ip = '1.2.3.4'
+        >>> a = [k8s_client.V1EndpointAddress(ip=ip)]
+        >>> s = [k8s_client.V1EndpointSubset(addresses=a)]
+        >>> Kubernetes.subsets_changed(s, '1.2.3.5', [])
         True
-        >>> a = [k8s_client.V1EndpointAddress(ip='1.2.3.4')]
-        >>> s1 = [k8s_client.V1EndpointSubset(addresses=a, ports=[k8s_client.V1EndpointPort(protocol='TCP', port=1)])]
-        >>> s2 = [k8s_client.V1EndpointSubset(addresses=a, ports=[k8s_client.V1EndpointPort(port=5432)])]
-        >>> Kubernetes.subsets_changed(s1, s2)
+        >>> s = [k8s_client.V1EndpointSubset(addresses=a, ports=[k8s_client.V1EndpointPort(protocol='TCP', port=1)])]
+        >>> Kubernetes.subsets_changed(s, '1.2.3.4', [k8s_client.V1EndpointPort(port=5432)])
         True
         >>> p1 = k8s_client.V1EndpointPort(name='port1', port=1)
         >>> p2 = k8s_client.V1EndpointPort(name='port2', port=2)
         >>> p3 = k8s_client.V1EndpointPort(name='port3', port=3)
-        >>> s1 = [k8s_client.V1EndpointSubset(addresses=a, ports=[p1, p2])]
-        >>> s2 = [k8s_client.V1EndpointSubset(addresses=a, ports=[p2, p3])]
-        >>> Kubernetes.subsets_changed(s1, s2)
+        >>> s = [k8s_client.V1EndpointSubset(addresses=a, ports=[p1, p2])]
+        >>> Kubernetes.subsets_changed(s, ip, [p2, p3])
         True
         >>> s2 = [k8s_client.V1EndpointSubset(addresses=a, ports=[p2, p1])]
-        >>> Kubernetes.subsets_changed(s1, s2)
+        >>> Kubernetes.subsets_changed(s, ip, [p2, p1])
         False
         """
-        if len(last_observed_subsets) != len(subsets):
+
+        if len(last_observed_subsets) != 1:
             return True
-        if subsets == []:
-            return False
         if len(last_observed_subsets[0].addresses or []) != 1 or \
-                last_observed_subsets[0].addresses[0].ip != subsets[0].addresses[0].ip or \
-                len(last_observed_subsets[0].ports) != len(subsets[0].ports):
+                last_observed_subsets[0].addresses[0].ip != ip or \
+                len(last_observed_subsets[0].ports) != len(ports):
             return True
-        if len(subsets[0].ports) == 1:
-            return not Kubernetes.compare_ports(last_observed_subsets[0].ports[0], subsets[0].ports[0])
+        if len(ports) == 1:
+            return not Kubernetes.compare_ports(last_observed_subsets[0].ports[0], ports[0])
         observed_ports = {p.name: p for p in last_observed_subsets[0].ports}
-        for p in subsets[0].ports:
+        for p in ports:
             if p.name not in observed_ports or not Kubernetes.compare_ports(p, observed_ports.pop(p.name)):
                 return True
         return False
 
-    @catch_kubernetes_errors
-    def patch_or_create(self, name, annotations, resource_version=None, patch=False, retry=True, subsets=None):
+    def __target_ref(self, leader_ip, latest_subsets, pod):
+        # we want to re-use existing target_ref if possible
+        for subset in latest_subsets:
+            for address in subset.addresses or []:
+                if address.ip == leader_ip and address.target_ref and address.target_ref.name == self._name:
+                    return address.target_ref
+        return k8s_client.V1ObjectReference(kind='Pod', uid=pod.metadata.uid, namespace=self._namespace,
+                                            name=self._name, resource_version=pod.metadata.resource_version)
+
+    def _map_subsets(self, endpoints, ips):
+        leader = self._kinds.get(self.leader_path)
+        latest_subsets = leader and leader.subsets or []
+        if not ips:
+            # We want to have subsets empty
+            if latest_subsets:
+                endpoints['subsets'] = []
+            return
+
+        pod = self._pods.get(self._name)
+        leader_ip = ips[0] or pod and pod.status.pod_ip
+        # don't touch subsets if our (leader) ip is unknown or subsets is valid
+        if leader_ip and self.subsets_changed(latest_subsets, leader_ip, self.__ports):
+            kwargs = {'hostname': pod.spec.hostname, 'node_name': pod.spec.node_name,
+                      'target_ref': self.__target_ref(leader_ip, latest_subsets, pod)} if pod else {}
+            address = k8s_client.V1EndpointAddress(ip=leader_ip, **kwargs)
+            endpoints['subsets'] = [k8s_client.V1EndpointSubset(addresses=[address], ports=self.__ports)]
+
+    def _patch_or_create(self, name, annotations, resource_version=None, patch=False, retry=None, ips=None):
         metadata = {'namespace': self._namespace, 'name': name, 'labels': self._labels, 'annotations': annotations}
         if patch or resource_version:
             if resource_version is not None:
@@ -426,27 +859,29 @@ class Kubernetes(AbstractDCS):
             metadata['annotations'] = {k: v for k, v in metadata['annotations'].items() if v is not None}
 
         metadata = k8s_client.V1ObjectMeta(**metadata)
-        if subsets is not None and self.__subsets:
+        if ips is not None and self._api.use_endpoints:
             endpoints = {'metadata': metadata}
-            if self.subsets_changed(self._leader_observed_subsets, subsets):
-                endpoints['subsets'] = subsets
+            self._map_subsets(endpoints, ips)
             body = k8s_client.V1Endpoints(**endpoints)
         else:
             body = k8s_client.V1ConfigMap(metadata=metadata)
-        ret = self.retry(func, self._namespace, body) if retry else func(self._namespace, body)
+        ret = retry(func, self._namespace, body) if retry else func(self._namespace, body)
         if ret:
             self._kinds.set(name, ret)
         return ret
 
+    @catch_kubernetes_errors
+    def patch_or_create(self, name, annotations, resource_version=None, patch=False, retry=True, ips=None):
+        if retry is True:
+            retry = self.retry
+        return self._patch_or_create(name, annotations, resource_version, patch, retry, ips)
+
     def patch_or_create_config(self, annotations, resource_version=None, patch=False, retry=True):
         # SCOPE-config endpoint requires corresponding service otherwise it might be "cleaned" by k8s master
-        if self.__subsets and not patch and not resource_version:
+        if self._api.use_endpoints and not patch and not resource_version:
             self._should_create_config_service = True
             self._create_config_service()
-        ret = self.patch_or_create(self.config_path, annotations, resource_version, patch, retry)
-        if ret:
-            self._config_resource_version = ret.metadata.resource_version
-        return ret
+        return self.patch_or_create(self.config_path, annotations, resource_version, patch, retry)
 
     def _create_config_service(self):
         metadata = k8s_client.V1ObjectMeta(namespace=self._namespace, name=self.config_path, labels=self._labels)
@@ -459,26 +894,77 @@ class Kubernetes(AbstractDCS):
                 return logger.exception('create_config_service failed')
         self._should_create_config_service = False
 
-    def _write_leader_optime(self, last_operation):
+    def _write_leader_optime(self, last_lsn):
+        """Unused"""
+
+    def _write_status(self, value):
         """Unused"""
 
     def _update_leader(self):
         """Unused"""
 
-    def update_leader(self, last_operation, access_is_restricted=False):
+    def _update_leader_with_retry(self, annotations, resource_version, ips):
+        retry = self._retry.copy()
+
+        def _retry(*args, **kwargs):
+            kwargs['_retry'] = retry
+            return retry(*args, **kwargs)
+
+        try:
+            return self._patch_or_create(self.leader_path, annotations, resource_version, ips=ips, retry=_retry)
+        except k8s_client.rest.ApiException as e:
+            if e.status == 409:
+                logger.warning('Concurrent update of %s', self.leader_path)
+            else:
+                logger.exception('Permission denied' if e.status == 403 else 'Unexpected error from Kubernetes API')
+                return False
+        except (RetryFailedError, K8sException):
+            return False
+
+        retry.deadline = retry.stoptime - time.time()
+        if retry.deadline < 1:
+            return False
+
+        # Try to get the latest version directly from K8s API instead of relying on async cache
+        try:
+            kind = _retry(self._api.read_namespaced_kind, self.leader_path, self._namespace)
+        except Exception as e:
+            logger.error('Failed to get the leader object "%s": %r', self.leader_path, e)
+            return False
+
+        self._kinds.set(self.leader_path, kind)
+
+        retry.deadline = retry.stoptime - time.time()
+        if retry.deadline < 0.5:
+            return False
+
+        kind_annotations = kind and kind.metadata.annotations or {}
+        kind_resource_version = kind and kind.metadata.resource_version
+
+        # There is different leader or resource_version in cache didn't change
+        if kind and (kind_annotations.get(self._LEADER) != self._name or kind_resource_version == resource_version):
+            return False
+
+        return self.patch_or_create(self.leader_path, annotations, kind_resource_version, ips=ips, retry=_retry)
+
+    def update_leader(self, last_lsn, slots=None):
+        kind = self._kinds.get(self.leader_path)
+        kind_annotations = kind and kind.metadata.annotations or {}
+
+        if kind and kind_annotations.get(self._LEADER) != self._name:
+            return False
+
         now = datetime.datetime.now(tzutc).isoformat()
+        leader_observed_record = kind_annotations or self._leader_observed_record
         annotations = {self._LEADER: self._name, 'ttl': str(self._ttl), 'renewTime': now,
-                       'acquireTime': self._leader_observed_record.get('acquireTime') or now,
-                       'transitions': self._leader_observed_record.get('transitions') or '0'}
-        if last_operation:
-            annotations[self._OPTIME] = last_operation
+                       'acquireTime': leader_observed_record.get('acquireTime') or now,
+                       'transitions': leader_observed_record.get('transitions') or '0'}
+        if last_lsn:
+            annotations[self._OPTIME] = str(last_lsn)
+        annotations['slots'] = json.dumps(slots) if slots else None
 
-        subsets = [] if access_is_restricted else self.__subsets
-
-        ret = self.patch_or_create(self.leader_path, annotations, self._leader_resource_version, subsets=subsets)
-        if ret:
-            self._leader_resource_version = ret.metadata.resource_version
-        return ret
+        resource_version = kind and kind.metadata.resource_version
+        return self._update_leader_with_retry(annotations, resource_version, self.__ips)
 
     def attempt_to_acquire_leader(self, permanent=False):
         now = datetime.datetime.now(tzutc).isoformat()
@@ -495,11 +981,9 @@ class Kubernetes(AbstractDCS):
             else:
                 annotations['acquireTime'] = self._leader_observed_record.get('acquireTime') or now
             annotations['transitions'] = str(transitions)
-        subsets = [] if self.__subsets else None
-        ret = self.patch_or_create(self.leader_path, annotations, self._leader_resource_version, subsets=subsets)
-        if ret:
-            self._leader_resource_version = ret.metadata.resource_version
-        else:
+        ips = [] if self._api.use_endpoints else None
+        ret = self.patch_or_create(self.leader_path, annotations, self._leader_resource_version, ips=ips)
+        if not ret:
             logger.info('Could not take out TTL lock')
         return ret
 
@@ -515,6 +999,11 @@ class Kubernetes(AbstractDCS):
         patch = bool(self.cluster and isinstance(self.cluster.failover, Failover) and self.cluster.failover.index)
         return self.patch_or_create(self.failover_path, annotations, index, bool(index or patch), False)
 
+    @property
+    def _config_resource_version(self):
+        config = self._kinds.get(self.config_path)
+        return config and config.metadata.resource_version
+
     def set_config_value(self, value, index=None):
         return self.patch_or_create_config({self._CONFIG: value}, index, bool(self._config_resource_version), False)
 
@@ -522,7 +1011,7 @@ class Kubernetes(AbstractDCS):
     def touch_member(self, data, permanent=False):
         cluster = self.cluster
         if cluster and cluster.leader and cluster.leader.name == self._name:
-            role = 'promoted' if data['role'] in ('replica', 'promoted') else 'master'
+            role = 'master'
         elif data['state'] == 'running' and data['role'] != 'master':
             role = data['role']
         else:
@@ -537,7 +1026,9 @@ class Kubernetes(AbstractDCS):
                         'annotations': {'status': json.dumps(data, separators=(',', ':'))}}
             body = k8s_client.V1Pod(metadata=k8s_client.V1ObjectMeta(**metadata))
             ret = self._api.patch_namespaced_pod(self._name, self._namespace, body)
-        if self.__subsets and self._should_create_config_service:
+            if ret:
+                self._pods.set(self._name, ret)
+        if self._should_create_config_service:
             self._create_config_service()
         return ret
 
@@ -546,9 +1037,16 @@ class Kubernetes(AbstractDCS):
         resource_version = cluster.config.index if cluster and cluster.config and cluster.config.index else None
         return self.patch_or_create_config({self._INITIALIZE: sysid}, resource_version)
 
-    def delete_leader(self):
-        if self.cluster and isinstance(self.cluster.leader, Leader) and self.cluster.leader.name == self._name:
-            self.patch_or_create(self.leader_path, {self._LEADER: None}, self._leader_resource_version, True, False, [])
+    def _delete_leader(self):
+        """Unused"""
+
+    def delete_leader(self, last_lsn=None):
+        kind = self._kinds.get(self.leader_path)
+        if kind and (kind.metadata.annotations or {}).get(self._LEADER) == self._name:
+            annotations = {self._LEADER: None}
+            if last_lsn:
+                annotations[self._OPTIME] = last_lsn
+            self.patch_or_create(self.leader_path, annotations, kind.metadata.resource_version, True, False, [])
             self.reset_cluster()
 
     def cancel_initialization(self):
@@ -576,6 +1074,6 @@ class Kubernetes(AbstractDCS):
             return True
 
         try:
-            return super(Kubernetes, self).watch(None, timeout)
+            return super(Kubernetes, self).watch(None, timeout + 0.5)
         finally:
             self.event.clear()

patroni/dcs/raft.py

@@ -0,0 +1,423 @@
+import json
+import logging
+import os
+import threading
+import time
+
+from pysyncobj import SyncObj, SyncObjConf, replicated, FAIL_REASON
+from pysyncobj.dns_resolver import globalDnsResolver
+from pysyncobj.node import TCPNode
+from pysyncobj.transport import TCPTransport, CONNECTION_STATE
+from pysyncobj.utility import TcpUtility
+
+from . import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
+from ..utils import validate_directory
+
+logger = logging.getLogger(__name__)
+
+
+class _TCPTransport(TCPTransport):
+
+    def __init__(self, syncObj, selfNode, otherNodes):
+        super(_TCPTransport, self).__init__(syncObj, selfNode, otherNodes)
+        self.setOnUtilityMessageCallback('members', syncObj.getMembers)
+
+    def _connectIfNecessarySingle(self, node):
+        try:
+            return super(_TCPTransport, self)._connectIfNecessarySingle(node)
+        except Exception as e:
+            logger.debug('Connection to %s failed: %r', node, e)
+            return False
+
+
+def resolve_host(self):
+    return globalDnsResolver().resolve(self.host)
+
+
+setattr(TCPNode, 'ip', property(resolve_host))
+
+
+class SyncObjUtility(object):
+
+    def __init__(self, otherNodes, conf):
+        self._nodes = otherNodes
+        self._utility = TcpUtility(conf.password)
+
+    def executeCommand(self, command):
+        try:
+            return self._utility.executeCommand(self.__node, command)
+        except Exception:
+            return None
+
+    def getMembers(self):
+        for self.__node in self._nodes:
+            response = self.executeCommand(['members'])
+            if response:
+                return [member['addr'] for member in response]
+
+
+class DynMemberSyncObj(SyncObj):
+
+    def __init__(self, selfAddress, partnerAddrs, conf):
+        self.__early_apply_local_log = selfAddress is not None
+        self.applied_local_log = False
+
+        utility = SyncObjUtility(partnerAddrs, conf)
+        members = utility.getMembers()
+        add_self = members and selfAddress not in members
+
+        partnerAddrs = [member for member in (members or partnerAddrs) if member != selfAddress]
+
+        super(DynMemberSyncObj, self).__init__(selfAddress, partnerAddrs, conf, transportClass=_TCPTransport)
+
+        if add_self:
+            thread = threading.Thread(target=utility.executeCommand, args=(['add', selfAddress],))
+            thread.daemon = True
+            thread.start()
+
+    def getMembers(self, args, callback):
+        callback([{'addr': node.id, 'leader': node == self._getLeader(), 'status': CONNECTION_STATE.CONNECTED
+                   if self.isNodeConnected(node) else CONNECTION_STATE.DISCONNECTED} for node in self.otherNodes] +
+                 [{'addr': self.selfNode.id, 'leader': self._isLeader(), 'status': CONNECTION_STATE.CONNECTED}], None)
+
+    def _onTick(self, timeToWait=0.0):
+        super(DynMemberSyncObj, self)._onTick(timeToWait)
+
+        # The SyncObj calls onReady callback only when cluster got the leader and is ready for writes.
+        # In some cases for us it is safe to "signal" the Raft object when the local log is fully applied.
+        # We are using the `applied_local_log` property for that, but not calling the callback function.
+        if self.__early_apply_local_log and not self.applied_local_log and self.raftLastApplied == self.raftCommitIndex:
+            self.applied_local_log = True
+
+
+class KVStoreTTL(DynMemberSyncObj):
+
+    def __init__(self, on_ready, on_set, on_delete, **config):
+        self.__thread = None
+        self.__on_set = on_set
+        self.__on_delete = on_delete
+        self.__limb = {}
+        self.__retry_timeout = None
+
+        self_addr = config.get('self_addr')
+        partner_addrs = set(config.get('partner_addrs', []))
+        if config.get('patronictl'):
+            if self_addr:
+                partner_addrs.add(self_addr)
+            self_addr = None
+
+        # Create raft data_dir if necessary
+        raft_data_dir = config.get('data_dir', '')
+        if raft_data_dir != '':
+            validate_directory(raft_data_dir)
+
+        file_template = (self_addr or '')
+        file_template = file_template.replace(':', '_') if os.name == 'nt' else file_template
+        file_template = os.path.join(raft_data_dir, file_template)
+        conf = SyncObjConf(password=config.get('password'), autoTick=False, appendEntriesUseBatch=False,
+                           bindAddress=config.get('bind_addr'), dnsFailCacheTime=(config.get('loop_wait') or 10),
+                           dnsCacheTime=(config.get('ttl') or 30), commandsWaitLeader=config.get('commandsWaitLeader'),
+                           fullDumpFile=(file_template + '.dump' if self_addr else None),
+                           journalFile=(file_template + '.journal' if self_addr else None),
+                           onReady=on_ready, dynamicMembershipChange=True)
+
+        super(KVStoreTTL, self).__init__(self_addr, partner_addrs, conf)
+        self.__data = {}
+
+    @staticmethod
+    def __check_requirements(old_value, **kwargs):
+        return ('prevExist' not in kwargs or bool(kwargs['prevExist']) == bool(old_value)) and \
+            ('prevValue' not in kwargs or old_value and old_value['value'] == kwargs['prevValue']) and \
+            (not kwargs.get('prevIndex') or old_value and old_value['index'] == kwargs['prevIndex'])
+
+    def set_retry_timeout(self, retry_timeout):
+        self.__retry_timeout = retry_timeout
+
+    def retry(self, func, *args, **kwargs):
+        event = threading.Event()
+        ret = {'result': None, 'error': -1}
+
+        def callback(result, error):
+            ret.update(result=result, error=error)
+            event.set()
+
+        kwargs['callback'] = callback
+        timeout = kwargs.pop('timeout', None) or self.__retry_timeout
+        deadline = timeout and time.time() + timeout
+
+        while True:
+            event.clear()
+            func(*args, **kwargs)
+            event.wait(timeout)
+            if ret['error'] == FAIL_REASON.SUCCESS:
+                return ret['result']
+            elif ret['error'] == FAIL_REASON.REQUEST_DENIED:
+                break
+            elif deadline:
+                timeout = deadline - time.time()
+                if timeout <= 0:
+                    break
+            time.sleep(1)
+        return False
+
+    @replicated
+    def _set(self, key, value, **kwargs):
+        old_value = self.__data.get(key, {})
+        if not self.__check_requirements(old_value, **kwargs):
+            return False
+
+        if old_value and old_value['created'] != value['created']:
+            value['created'] = value['updated']
+        value['index'] = self.raftLastApplied + 1
+
+        self.__data[key] = value
+        if self.__on_set:
+            self.__on_set(key, value)
+        return True
+
+    def set(self, key, value, ttl=None, **kwargs):
+        old_value = self.__data.get(key, {})
+        if not self.__check_requirements(old_value, **kwargs):
+            return False
+
+        value = {'value': value, 'updated': time.time()}
+        value['created'] = old_value.get('created', value['updated'])
+        if ttl:
+            value['expire'] = value['updated'] + ttl
+        return self.retry(self._set, key, value, **kwargs)
+
+    def __pop(self, key):
+        self.__data.pop(key)
+        if self.__on_delete:
+            self.__on_delete(key)
+
+    @replicated
+    def _delete(self, key, recursive=False, **kwargs):
+        if recursive:
+            for k in list(self.__data.keys()):
+                if k.startswith(key):
+                    self.__pop(k)
+        elif not self.__check_requirements(self.__data.get(key, {}), **kwargs):
+            return False
+        else:
+            self.__pop(key)
+        return True
+
+    def delete(self, key, recursive=False, **kwargs):
+        if not recursive and not self.__check_requirements(self.__data.get(key, {}), **kwargs):
+            return False
+        return self.retry(self._delete, key, recursive=recursive, **kwargs)
+
+    @staticmethod
+    def __values_match(old, new):
+        return all(old.get(n) == new.get(n) for n in ('created', 'updated', 'expire', 'value'))
+
+    @replicated
+    def _expire(self, key, value, callback=None):
+        current = self.__data.get(key)
+        if current and self.__values_match(current, value):
+            self.__pop(key)
+
+    def __expire_keys(self):
+        for key, value in self.__data.items():
+            if value and 'expire' in value and value['expire'] <= time.time() and \
+                    not (key in self.__limb and self.__values_match(self.__limb[key], value)):
+                self.__limb[key] = value
+
+                def callback(*args):
+                    if key in self.__limb and self.__values_match(self.__limb[key], value):
+                        self.__limb.pop(key)
+                self._expire(key, value, callback=callback)
+
+    def get(self, key, recursive=False):
+        if not recursive:
+            return self.__data.get(key)
+        return {k: v for k, v in self.__data.items() if k.startswith(key)}
+
+    def _onTick(self, timeToWait=0.0):
+        super(KVStoreTTL, self)._onTick(timeToWait)
+
+        if self._isLeader():
+            self.__expire_keys()
+        else:
+            self.__limb.clear()
+
+    def _autoTickThread(self):
+        self.__destroying = False
+        while not self.__destroying:
+            self.doTick(self.conf.autoTickPeriod)
+
+    def startAutoTick(self):
+        self.__thread = threading.Thread(target=self._autoTickThread)
+        self.__thread.daemon = True
+        self.__thread.start()
+
+    def destroy(self):
+        if self.__thread:
+            self.__destroying = True
+            self.__thread.join()
+        super(KVStoreTTL, self).destroy()
+
+
+class Raft(AbstractDCS):
+
+    def __init__(self, config):
+        super(Raft, self).__init__(config)
+        self._ttl = int(config.get('ttl') or 30)
+
+        ready_event = threading.Event()
+        self._sync_obj = KVStoreTTL(ready_event.set, self._on_set, self._on_delete, commandsWaitLeader=False, **config)
+        self._sync_obj.startAutoTick()
+
+        while True:
+            ready_event.wait(5)
+            if ready_event.isSet() or self._sync_obj.applied_local_log:
+                break
+            else:
+                logger.info('waiting on raft')
+        self.set_retry_timeout(int(config.get('retry_timeout') or 10))
+
+    def _on_set(self, key, value):
+        leader = (self._sync_obj.get(self.leader_path) or {}).get('value')
+        if key == value['created'] == value['updated'] and \
+                (key.startswith(self.members_path) or key == self.leader_path and leader != self._name) or \
+                key in (self.leader_optime_path, self.status_path) and leader != self._name or \
+                key in (self.config_path, self.sync_path):
+            self.event.set()
+
+    def _on_delete(self, key):
+        if key == self.leader_path:
+            self.event.set()
+
+    def set_ttl(self, ttl):
+        self._ttl = ttl
+
+    @property
+    def ttl(self):
+        return self._ttl
+
+    def set_retry_timeout(self, retry_timeout):
+        self._sync_obj.set_retry_timeout(retry_timeout)
+
+    def reload_config(self, config):
+        super(Raft, self).reload_config(config)
+        globalDnsResolver().setTimeouts(self.ttl, self.loop_wait)
+
+    @staticmethod
+    def member(key, value):
+        return Member.from_node(value['index'], os.path.basename(key), None, value['value'])
+
+    def _load_cluster(self):
+        prefix = self.client_path('')
+        response = self._sync_obj.get(prefix, recursive=True)
+        if not response:
+            return Cluster(None, None, None, None, [], None, None, None, None)
+        nodes = {os.path.relpath(key, prefix).replace('\\', '/'): value for key, value in response.items()}
+
+        # get initialize flag
+        initialize = nodes.get(self._INITIALIZE)
+        initialize = initialize and initialize['value']
+
+        # get global dynamic configuration
+        config = nodes.get(self._CONFIG)
+        config = config and ClusterConfig.from_node(config['index'], config['value'])
+
+        # get timeline history
+        history = nodes.get(self._HISTORY)
+        history = history and TimelineHistory.from_node(history['index'], history['value'])
+
+        # get last know leader lsn and slots
+        status = nodes.get(self._STATUS)
+        if status:
+            try:
+                status = json.loads(status['value'])
+                last_lsn = status.get(self._OPTIME)
+                slots = status.get('slots')
+            except Exception:
+                slots = last_lsn = None
+        else:
+            last_lsn = nodes.get(self._LEADER_OPTIME)
+            last_lsn = last_lsn and last_lsn['value']
+            slots = None
+
+        try:
+            last_lsn = int(last_lsn)
+        except Exception:
+            last_lsn = 0
+
+        # get list of members
+        members = [self.member(k, n) for k, n in nodes.items() if k.startswith(self._MEMBERS) and k.count('/') == 1]
+
+        # get leader
+        leader = nodes.get(self._LEADER)
+        if leader:
+            member = Member(-1, leader['value'], None, {})
+            member = ([m for m in members if m.name == leader['value']] or [member])[0]
+            leader = Leader(leader['index'], None, member)
+
+        # failover key
+        failover = nodes.get(self._FAILOVER)
+        if failover:
+            failover = Failover.from_node(failover['index'], failover['value'])
+
+        # get synchronization state
+        sync = nodes.get(self._SYNC)
+        sync = SyncState.from_node(sync and sync['index'], sync and sync['value'])
+
+        return Cluster(initialize, config, leader, last_lsn, members, failover, sync, history, slots)
+
+    def _write_leader_optime(self, last_lsn):
+        return self._sync_obj.set(self.leader_optime_path, last_lsn, timeout=1)
+
+    def _write_status(self, value):
+        return self._sync_obj.set(self.status_path, value, timeout=1)
+
+    def _update_leader(self):
+        ret = self._sync_obj.set(self.leader_path, self._name, ttl=self._ttl, prevValue=self._name)
+        if not ret and self._sync_obj.get(self.leader_path) is None:
+            ret = self.attempt_to_acquire_leader()
+        return ret
+
+    def attempt_to_acquire_leader(self, permanent=False):
+        return self._sync_obj.set(self.leader_path, self._name, prevExist=False,
+                                  ttl=None if permanent else self._ttl)
+
+    def set_failover_value(self, value, index=None):
+        return self._sync_obj.set(self.failover_path, value, prevIndex=index)
+
+    def set_config_value(self, value, index=None):
+        return self._sync_obj.set(self.config_path, value, prevIndex=index)
+
+    def touch_member(self, data, permanent=False):
+        data = json.dumps(data, separators=(',', ':'))
+        return self._sync_obj.set(self.member_path, data, None if permanent else self._ttl, timeout=2)
+
+    def take_leader(self):
+        return self._sync_obj.set(self.leader_path, self._name, ttl=self._ttl)
+
+    def initialize(self, create_new=True, sysid=''):
+        return self._sync_obj.set(self.initialize_path, sysid, prevExist=(not create_new))
+
+    def _delete_leader(self):
+        return self._sync_obj.delete(self.leader_path, prevValue=self._name, timeout=1)
+
+    def cancel_initialization(self):
+        return self._sync_obj.delete(self.initialize_path)
+
+    def delete_cluster(self):
+        return self._sync_obj.delete(self.client_path(''), recursive=True)
+
+    def set_history_value(self, value):
+        return self._sync_obj.set(self.history_path, value)
+
+    def set_sync_state_value(self, value, index=None):
+        return self._sync_obj.set(self.sync_path, value, prevIndex=index)
+
+    def delete_sync_state(self, index=None):
+        return self._sync_obj.delete(self.sync_path, prevIndex=index)
+
+    def watch(self, leader_index, timeout):
+        try:
+            return super(Raft, self).watch(leader_index, timeout)
+        finally:
+            self.event.clear()

patroni/dcs/zookeeper.py

@@ -4,11 +4,14 @@ import select
 import time
 
 from kazoo.client import KazooClient, KazooState, KazooRetry
-from kazoo.exceptions import NoNodeError, NodeExistsError
+from kazoo.exceptions import NoNodeError, NodeExistsError, SessionExpiredError
 from kazoo.handlers.threading import SequentialThreadingHandler
-from patroni.dcs import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
-from patroni.exceptions import DCSError
-from patroni.utils import deep_compare
+from kazoo.protocol.states import KeeperState
+from kazoo.security import make_acl
+
+from . import AbstractDCS, ClusterConfig, Cluster, Failover, Leader, Member, SyncState, TimelineHistory
+from ..exceptions import DCSError
+from ..utils import deep_compare
 
 logger = logging.getLogger(__name__)
 
@@ -54,6 +57,20 @@ class PatroniSequentialThreadingHandler(SequentialThreadingHandler):
             raise select.error(9, str(e))
 
 
+class PatroniKazooClient(KazooClient):
+
+    def _call(self, request, async_object):
+        # Before kazoo==2.7.0 it wasn't possible to send requests to zookeeper if
+        # the connection is in the SUSPENDED state and Patroni was strongly relying on it.
+        # The https://github.com/python-zk/kazoo/pull/588 changed it, and now such requests are queued.
+        # We override the `_call()` method in order to keep the old behavior.
+
+        if self._state == KeeperState.CONNECTING:
+            async_object.set_exception(SessionExpiredError())
+            return False
+        return super(PatroniKazooClient, self)._call(request, async_object)
+
+
 class ZooKeeper(AbstractDCS):
 
     def __init__(self, config):
@@ -63,13 +80,32 @@ class ZooKeeper(AbstractDCS):
         if isinstance(hosts, list):
             hosts = ','.join(hosts)
 
-        self._client = KazooClient(hosts, handler=PatroniSequentialThreadingHandler(config['retry_timeout']),
-                                   timeout=config['ttl'], connection_retry=KazooRetry(max_delay=1, max_tries=-1,
-                                   sleep_func=time.sleep), command_retry=KazooRetry(deadline=config['retry_timeout'],
-                                   max_delay=1, max_tries=-1, sleep_func=time.sleep))
+        mapping = {'use_ssl': 'use_ssl', 'verify': 'verify_certs', 'cacert': 'ca',
+                   'cert': 'certfile', 'key': 'keyfile', 'key_password': 'keyfile_password'}
+        kwargs = {v: config[k] for k, v in mapping.items() if k in config}
+
+        if 'set_acls' in config:
+            kwargs['default_acl'] = []
+            for principal, permissions in config['set_acls'].items():
+                normalizedPermissions = [p.upper() for p in permissions]
+                kwargs['default_acl'].append(make_acl(scheme='x509',
+                                                      credential=principal,
+                                                      read='READ' in normalizedPermissions,
+                                                      write='WRITE' in normalizedPermissions,
+                                                      create='CREATE' in normalizedPermissions,
+                                                      delete='DELETE' in normalizedPermissions,
+                                                      admin='ADMIN' in normalizedPermissions,
+                                                      all='ALL' in normalizedPermissions))
+
+        self._client = PatroniKazooClient(hosts, handler=PatroniSequentialThreadingHandler(config['retry_timeout']),
+                                          timeout=config['ttl'], connection_retry=KazooRetry(max_delay=1, max_tries=-1,
+                                          sleep_func=time.sleep), command_retry=KazooRetry(max_delay=1, max_tries=-1,
+                                          deadline=config['retry_timeout'], sleep_func=time.sleep), **kwargs)
         self._client.add_listener(self.session_listener)
 
         self._fetch_cluster = True
+        self._fetch_status = True
+        self.__last_member_data = None
 
         self._orig_kazoo_connect = self._client._connection._connect
         self._client._connection._connect = self._kazoo_connect
@@ -95,9 +131,13 @@ class ZooKeeper(AbstractDCS):
         if state in [KazooState.SUSPENDED, KazooState.LOST]:
             self.cluster_watcher(None)
 
+    def status_watcher(self, event):
+        self._fetch_status = True
+        self.event.set()
+
     def cluster_watcher(self, event):
         self._fetch_cluster = True
-        self.event.set()
+        self.status_watcher(event)
 
     def reload_config(self, config):
         self.set_retry_timeout(config['retry_timeout'])
@@ -114,13 +154,14 @@ class ZooKeeper(AbstractDCS):
         # the same time, set_ttl method will reestablish connection and return
         # `!True`, otherwise we will close existing connection and let kazoo
         # open the new one.
-        if not self.set_ttl(int(config['ttl'] * 1000)) and loop_wait_changed:
+        if not self.set_ttl(config['ttl']) and loop_wait_changed:
             self._client._connection._socket.close()
 
     def set_ttl(self, ttl):
         """It is not possible to change ttl (session_timeout) in zookeeper without
         destroying old session and creating the new one. This method returns `!True`
         if session_timeout has been changed (`restart()` has been called)."""
+        ttl = int(ttl * 1000)
         if self._client._session_timeout != ttl:
             self._client._session_timeout = ttl
             self._client.restart()
@@ -128,7 +169,7 @@ class ZooKeeper(AbstractDCS):
 
     @property
     def ttl(self):
-        return self._client._session_timeout
+        return self._client._session_timeout / 1000.0
 
     def set_retry_timeout(self, retry_timeout):
         retry = self._client.retry if isinstance(self._client.retry, KazooRetry) else self._client._retry
@@ -141,6 +182,30 @@ class ZooKeeper(AbstractDCS):
         except NoNodeError:
             return None
 
+    def get_status(self, leader):
+        watch = self.status_watcher if not leader or leader.name != self._name else None
+
+        status = self.get_node(self.status_path, watch)
+        if status:
+            try:
+                status = json.loads(status[0])
+                last_lsn = status.get(self._OPTIME)
+                slots = status.get('slots')
+            except Exception:
+                slots = last_lsn = None
+        else:
+            last_lsn = self.get_node(self.leader_optime_path, watch)
+            last_lsn = last_lsn and last_lsn[0]
+            slots = None
+
+        try:
+            last_lsn = int(last_lsn)
+        except Exception:
+            last_lsn = 0
+
+        self._fetch_status = False
+        return last_lsn, slots
+
     @staticmethod
     def member(name, value, znode):
         return Member.from_node(znode.version, name, znode.ephemeralOwner, value)
@@ -151,11 +216,10 @@ class ZooKeeper(AbstractDCS):
         except NoNodeError:
             return []
 
-    def load_members(self, sync_standby):
+    def load_members(self):
         members = []
         for member in self.get_children(self.members_path, self.cluster_watcher):
-            watch = member == sync_standby and self.cluster_watcher or None
-            data = self.get_node(self.members_path + member, watch)
+            data = self.get_node(self.members_path + member)
             if data is not None:
                 members.append(self.member(member, *data))
         return members
@@ -178,17 +242,12 @@ class ZooKeeper(AbstractDCS):
         history = self.get_node(self.history_path, watch=self.cluster_watcher) if self._HISTORY in nodes else None
         history = history and TimelineHistory.from_node(history[1].mzxid, history[0])
 
-        # get last leader operation
-        last_leader_operation = self._OPTIME in nodes and self._fetch_cluster and self.get_node(self.leader_optime_path)
-        last_leader_operation = last_leader_operation and int(last_leader_operation[0]) or 0
-
         # get synchronization state
         sync = self.get_node(self.sync_path, watch=self.cluster_watcher) if self._SYNC in nodes else None
         sync = SyncState.from_node(sync and sync[1].version, sync and sync[0])
 
         # get list of members
-        sync_standby = sync.leader == self._name and sync.sync_standby or None
-        members = self.load_members(sync_standby) if self._MEMBERS[:-1] in nodes else []
+        members = self.load_members() if self._MEMBERS[:-1] in nodes else []
 
         # get leader
         leader = self.get_node(self.leader_path) if self._LEADER in nodes else None
@@ -206,11 +265,14 @@ class ZooKeeper(AbstractDCS):
                 leader = Leader(leader[1].version, leader[1].ephemeralOwner, member)
                 self._fetch_cluster = member.index == -1
 
+        # get last known leader lsn and slots
+        last_lsn, slots = self.get_status(leader)
+
         # failover key
         failover = self.get_node(self.failover_path, watch=self.cluster_watcher) if self._FAILOVER in nodes else None
         failover = failover and Failover.from_node(failover[1].version, failover[0])
 
-        return Cluster(initialize, config, leader, last_leader_operation, members, failover, sync, history)
+        return Cluster(initialize, config, leader, last_lsn, members, failover, sync, history, slots)
 
     def _load_cluster(self):
         cluster = self.cluster
@@ -221,8 +283,25 @@ class ZooKeeper(AbstractDCS):
                 logger.exception('get_cluster')
                 self.cluster_watcher(None)
                 raise ZooKeeperError('ZooKeeper in not responding properly')
+        # The /status ZNode was updated or doesn't exist
+        elif self._fetch_status and not self._fetch_cluster or not cluster.last_lsn \
+                or cluster.has_permanent_logical_slots(self._name, False) and not cluster.slots:
+            # If current node is the leader just clear the event without fetching anything (we are updating the /status)
+            if cluster.leader and cluster.leader.name == self._name:
+                self.event.clear()
+            else:
+                try:
+                    last_lsn, slots = self.get_status(cluster.leader)
+                    self.event.clear()
+                    cluster = Cluster(cluster.initialize, cluster.config, cluster.leader, last_lsn,
+                                      cluster.members, cluster.failover, cluster.sync, cluster.history, slots)
+                except Exception:
+                    pass
         return cluster
 
+    def _bypass_caches(self):
+        self._fetch_cluster = True
+
     def _create(self, path, value, retry=False, ephemeral=False):
         try:
             if retry:
@@ -273,11 +352,11 @@ class ZooKeeper(AbstractDCS):
     def touch_member(self, data, permanent=False):
         cluster = self.cluster
         member = cluster and cluster.get_member(self._name, fallback_to_leader=False)
-        encoded_data = json.dumps(data, separators=(',', ':')).encode('utf-8')
+        member_data = self.__last_member_data or member and member.data
         if member and (self._client.client_id is not None and member.session != self._client.client_id[0] or
-                       not (deep_compare(member.data.get('tags', {}), data.get('tags', {})) and
-                            member.data.get('version') == data.get('version') and
-                            member.data.get('checkpoint_after_promote') == data.get('checkpoint_after_promote'))):
+                       not (deep_compare(member_data.get('tags', {}), data.get('tags', {})) and
+                            member_data.get('version') == data.get('version') and
+                            member_data.get('checkpoint_after_promote') == data.get('checkpoint_after_promote'))):
             try:
                 self._client.delete_async(self.member_path).get(timeout=1)
             except NoNodeError:
@@ -286,13 +365,15 @@ class ZooKeeper(AbstractDCS):
                 return False
             member = None
 
+        encoded_data = json.dumps(data, separators=(',', ':')).encode('utf-8')
         if member:
-            if deep_compare(data, member.data):
+            if deep_compare(data, member_data):
                 return True
         else:
             try:
                 self._client.create_async(self.member_path, encoded_data, makepath=True,
                                           ephemeral=not permanent).get(timeout=1)
+                self.__last_member_data = data
                 return True
             except Exception as e:
                 if not isinstance(e, NodeExistsError):
@@ -300,6 +381,7 @@ class ZooKeeper(AbstractDCS):
                     return False
         try:
             self._client.set_async(self.member_path, encoded_data).get(timeout=1)
+            self.__last_member_data = data
             return True
         except Exception:
             logger.exception('touch_member')
@@ -309,13 +391,16 @@ class ZooKeeper(AbstractDCS):
     def take_leader(self):
         return self.attempt_to_acquire_leader()
 
-    def _write_leader_optime(self, last_operation):
-        return self._set_or_create(self.leader_optime_path, last_operation)
+    def _write_leader_optime(self, last_lsn):
+        return self._set_or_create(self.leader_optime_path, last_lsn)
+
+    def _write_status(self, value):
+        return self._set_or_create(self.status_path, value)
 
     def _update_leader(self):
         return True
 
-    def delete_leader(self):
+    def _delete_leader(self):
         self._client.restart()
         return True
 
@@ -346,6 +431,7 @@ class ZooKeeper(AbstractDCS):
         return self.set_sync_state_value("{}", index)
 
     def watch(self, leader_index, timeout):
-        if super(ZooKeeper, self).watch(leader_index, timeout):
+        ret = super(ZooKeeper, self).watch(leader_index, timeout + 0.5)
+        if ret and not self._fetch_status:
             self._fetch_cluster = True
-        return self._fetch_cluster
+        return ret or self._fetch_cluster

patroni/exceptions.py

@@ -13,6 +13,10 @@ class PatroniException(Exception):
         return repr(self.value)
 
 
+class PatroniFatalException(PatroniException):
+    pass
+
+
 class PostgresException(PatroniException):
     pass
 

patroni/ha.py

@@ -2,32 +2,36 @@ import datetime
 import functools
 import json
 import logging
-import psycopg2
+import six
 import sys
 import time
 import uuid
 
 from collections import namedtuple
 from multiprocessing.pool import ThreadPool
-from patroni.async_executor import AsyncExecutor, CriticalTask
-from patroni.exceptions import DCSError, PostgresConnectionException, PatroniException
-from patroni.postgresql import ACTION_ON_START, ACTION_ON_ROLE_CHANGE
-from patroni.postgresql.misc import postgres_version_to_int
-from patroni.postgresql.rewind import Rewind
-from patroni.utils import polling_loop, tzutc, is_standby_cluster as _is_standby_cluster, parse_int
-from patroni.dcs import RemoteMember
 from threading import RLock
 
+from . import psycopg
+from .async_executor import AsyncExecutor, CriticalTask
+from .exceptions import DCSError, PostgresConnectionException, PatroniFatalException
+from .postgresql import ACTION_ON_START, ACTION_ON_ROLE_CHANGE
+from .postgresql.misc import postgres_version_to_int
+from .postgresql.rewind import Rewind
+from .utils import polling_loop, tzutc, is_standby_cluster as _is_standby_cluster, parse_int
+from .dcs import RemoteMember
+
 logger = logging.getLogger(__name__)
 
 
-class _MemberStatus(namedtuple('_MemberStatus', ['member', 'reachable', 'in_recovery', 'timeline',
-                                                 'wal_position', 'tags', 'watchdog_failed'])):
+class _MemberStatus(namedtuple('_MemberStatus', ['member', 'reachable', 'in_recovery',
+                                                 'dcs_last_seen', 'timeline', 'wal_position',
+                                                 'tags', 'watchdog_failed'])):
     """Node status distilled from API response:
 
         member - dcs.Member object of the node
         reachable - `!False` if the node is not reachable or is not responding with correct JSON
         in_recovery - `!True` if pg_is_in_recovery() == true
+        dcs_last_seen - timestamp from JSON of last succesful communication with DCS
         timeline - timeline value from JSON
         wal_position - maximum value of `replayed_location` or `received_location` from JSON
         tags - dictionary with values of different tags (i.e. nofailover)
@@ -37,12 +41,14 @@ class _MemberStatus(namedtuple('_MemberStatus', ['member', 'reachable', 'in_reco
     def from_api_response(cls, member, json):
         is_master = json['role'] == 'master'
         timeline = json.get('timeline', 0)
+        dcs_last_seen = json.get('dcs_last_seen', 0)
         wal = not is_master and max(json['xlog'].get('received_location', 0), json['xlog'].get('replayed_location', 0))
-        return cls(member, True, not is_master, timeline, wal, json.get('tags', {}), json.get('watchdog_failed', False))
+        return cls(member, True, not is_master, dcs_last_seen, timeline, wal,
+                   json.get('tags', {}), json.get('watchdog_failed', False))
 
     @classmethod
     def unknown(cls, member):
-        return cls(member, False, None, 0, 0, {}, False)
+        return cls(member, False, None, 0, 0, 0, {}, False)
 
     def failover_limitation(self):
         """Returns reason why this node can't promote or None if everything is ok."""
@@ -66,12 +72,12 @@ class Ha(object):
         self.old_cluster = None
         self._is_leader = False
         self._is_leader_lock = RLock()
-        self._leader_access_is_restricted = False
         self._was_paused = False
         self._leader_timeline = None
         self.recovering = False
-        self._post_bootstrap_task = None
+        self._async_response = CriticalTask()
         self._crash_recovery_executed = False
+        self._crash_recovery_started = None
         self._start_timeout = None
         self._async_executor = AsyncExecutor(self.state_handler.cancellable, self.wakeup)
         self.watchdog = patroni.watchdog
@@ -84,9 +90,12 @@ class Ha(object):
         self._disable_sync = 0
 
         # We need following property to avoid shutdown of postgres when join of Patroni to the postgres
-        # already running as replica was aborted due to cluster not beeing initialized in DCS.
+        # already running as replica was aborted due to cluster not being initialized in DCS.
         self._join_aborted = False
 
+        # used only in backoff after failing a pre_promote script
+        self._released_leader_key_timestamp = 0
+
     def check_mode(self, mode):
         # Try to protect from the case when DCS was wiped out during pause
         if self.cluster and self.cluster.config and self.cluster.config.modify_index:
@@ -117,16 +126,12 @@ class Ha(object):
 
     def is_leader(self):
         with self._is_leader_lock:
-            return self._is_leader > time.time() and not self._leader_access_is_restricted
+            return self._is_leader > time.time()
 
     def set_is_leader(self, value):
         with self._is_leader_lock:
             self._is_leader = time.time() + self.dcs.ttl if value else 0
 
-    def set_leader_access_is_restricted(self, value):
-        with self._is_leader_lock:
-            self._leader_access_is_restricted = value
-
     def load_cluster_from_dcs(self):
         cluster = self.dcs.get_cluster()
 
@@ -141,19 +146,23 @@ class Ha(object):
         self._leader_timeline = None if cluster.is_unlocked() else cluster.leader.timeline
 
     def acquire_lock(self):
-        self.set_leader_access_is_restricted(self.cluster.has_permanent_logical_slots(self.state_handler.name))
         ret = self.dcs.attempt_to_acquire_leader()
         self.set_is_leader(ret)
         return ret
 
     def update_lock(self, write_leader_optime=False):
-        last_operation = None
+        last_lsn = slots = None
         if write_leader_optime:
             try:
-                last_operation = self.state_handler.last_operation()
+                last_lsn = self.state_handler.last_operation()
+                slots = self.state_handler.slots()
             except Exception:
                 logger.exception('Exception when called state_handler.last_operation()')
-        ret = self.dcs.update_leader(last_operation, self._leader_access_is_restricted)
+        try:
+            ret = self.dcs.update_leader(last_lsn, slots)
+        except Exception:
+            logger.exception('Unexpected exception raised from update_leader, please report it as a BUG')
+            ret = False
         self.set_is_leader(ret)
         if ret:
             self.watchdog.keepalive()
@@ -183,9 +192,6 @@ class Ha(object):
                 'version': self.patroni.version
             }
 
-            # following two lines are mainly necessary for consul, to avoid creation of master service
-            if data['role'] == 'master' and not self.is_leader():
-                data['role'] = 'promoted'
             if self.is_leader() and not self._rewind.checkpoint_after_promote():
                 data['checkpoint_after_promote'] = False
             tags = self.get_effective_tags()
@@ -198,6 +204,8 @@ class Ha(object):
                 try:
                     timeline, wal_position, pg_control_timeline = self.state_handler.timeline_wal_position()
                     data['xlog_location'] = wal_position
+                    if not timeline:  # try pg_stat_wal_receiver to get the timeline
+                        timeline = self.state_handler.received_timeline()
                     if not timeline:
                         # So far the only way to get the current timeline on the standby is from
                         # the replication connection. In order to avoid opening the replication
@@ -250,7 +258,8 @@ class Ha(object):
         elif self.cluster.initialize is None and not self.patroni.nofailover and 'bootstrap' in self.patroni.config:
             if self.dcs.initialize(create_new=True):  # race for initialization
                 self.state_handler.bootstrapping = True
-                self._post_bootstrap_task = CriticalTask()
+                with self._async_response:
+                    self._async_response.reset()
 
                 if self.is_standby_cluster():
                     ret = self._async_executor.try_run_async('bootstrap_standby_leader', self.bootstrap_standby_leader)
@@ -277,7 +286,8 @@ class Ha(object):
         clone_source = self.get_remote_master()
         msg = 'clone from remote master {0}'.format(clone_source.conn_url)
         result = self.clone(clone_source, msg)
-        self._post_bootstrap_task.complete(result)
+        with self._async_response:  # pretend that post_bootstrap was already executed
+            self._async_response.complete(result)
         if result:
             self.state_handler.set_role('standby_leader')
 
@@ -306,10 +316,7 @@ class Ha(object):
             if timeout == 0:
                 # We are requested to prefer failing over to restarting master. But see first if there
                 # is anyone to fail over to.
-                members = self.cluster.members
-                if self.is_synchronous_mode():
-                    members = [m for m in members if self.cluster.sync.matches(m.name)]
-                if self.is_failover_possible(members):
+                if self.is_failover_possible(self.cluster.members):
                     logger.info("Master crashed. Failing over.")
                     self.demote('immediate')
                     return 'stopped PostgreSQL to fail over after a crash'
@@ -322,8 +329,9 @@ class Ha(object):
                 and not self._crash_recovery_executed and \
                 (self.cluster.is_unlocked() or self._rewind.can_rewind):
             self._crash_recovery_executed = True
+            self._crash_recovery_started = time.time()
             msg = 'doing crash recovery in a single user mode'
-            return self._async_executor.try_run_async(msg, self.state_handler.fix_cluster_state) or msg
+            return self._async_executor.try_run_async(msg, self._rewind.ensure_clean_shutdown) or msg
 
         self.load_cluster_from_dcs()
 
@@ -364,7 +372,7 @@ class Ha(object):
         elif self.patroni.replicatefrom and self.patroni.replicatefrom != self.state_handler.name:
             node_to_follow = cluster.get_member(self.patroni.replicatefrom)
         else:
-            node_to_follow = cluster.leader
+            node_to_follow = cluster.leader if cluster.leader and cluster.leader.name else None
 
         node_to_follow = node_to_follow if node_to_follow and node_to_follow.name != self.state_handler.name else None
 
@@ -389,19 +397,29 @@ class Ha(object):
         if self.is_paused():
             if not (self._rewind.is_needed and self._rewind.can_rewind_or_reinitialize_allowed)\
                     or self.cluster.is_unlocked():
-                self.state_handler.set_role('master' if is_leader else 'replica')
                 if is_leader:
+                    self.state_handler.set_role('master')
                     return 'continue to run as master without lock'
-                elif not node_to_follow:
-                    return 'no action'
+                elif self.state_handler.role != 'standby_leader':
+                    self.state_handler.set_role('replica')
+
+                if not node_to_follow:
+                    return 'no action. I am ({0})'.format(self.state_handler.name)
         elif is_leader:
             self.demote('immediate-nolock')
             return demote_reason
 
+        if self.is_standby_cluster() and self._leader_timeline and \
+                self.state_handler.get_history(self._leader_timeline + 1):
+            self._rewind.trigger_check_diverged_lsn()
+
         msg = self._handle_rewind_or_reinitialize()
         if msg:
             return msg
 
+        if not self.is_paused():
+            self.state_handler.handle_parameter_change()
+
         role = 'standby_leader' if isinstance(node_to_follow, RemoteMember) and self.has_lock(False) else 'replica'
         # It might happen that leader key in the standby cluster references non-exiting member.
         # In this case it is safe to continue running without changing recovery.conf
@@ -415,6 +433,7 @@ class Ha(object):
                                                        self.state_handler.follow, args=(node_to_follow, role))
                 else:
                     self.state_handler.follow(node_to_follow, role, do_reload=True)
+                self._rewind.trigger_check_diverged_lsn()
             elif role == 'standby_leader' and self.state_handler.role != role:
                 self.state_handler.set_role(role)
                 self.state_handler.call_nowait(ACTION_ON_ROLE_CHANGE)
@@ -437,28 +456,38 @@ class Ha(object):
         promoting standbys that were guaranteed to be replicating synchronously.
         """
         if self.is_synchronous_mode():
-            current = self.cluster.sync.leader and self.cluster.sync.sync_standby
-            picked, allow_promote = self.state_handler.pick_synchronous_standby(self.cluster)
-            if picked != current:
-                # We need to revoke privilege from current before replacing it in the config
-                if current:
-                    logger.info("Removing synchronous privilege from %s", current)
-                    if not self.dcs.write_sync_state(self.state_handler.name, None, index=self.cluster.sync.index):
+            sync_node_count = self.patroni.config['synchronous_node_count']
+            current = self.cluster.sync.leader and self.cluster.sync.members or []
+            picked, allow_promote = self.state_handler.pick_synchronous_standby(self.cluster, sync_node_count,
+                                                                                self.patroni.config[
+                                                                                    'maximum_lag_on_syncnode'])
+            if set(picked) != set(current):
+                # update synchronous standby list in dcs temporarily to point to common nodes in current and picked
+                sync_common = list(set(current).intersection(set(allow_promote)))
+                if set(sync_common) != set(current):
+                    logger.info("Updating synchronous privilege temporarily from %s to %s", current, sync_common)
+                    if not self.dcs.write_sync_state(self.state_handler.name,
+                                                     sync_common or None,
+                                                     index=self.cluster.sync.index):
                         logger.info('Synchronous replication key updated by someone else.')
                         return
 
-                if self.is_synchronous_mode_strict() and picked is None:
-                    picked = '*'
+                # Update  db param and wait for x secs
+                if self.is_synchronous_mode_strict() and not picked:
+                    picked = ['*']
                     logger.warning("No standbys available!")
 
                 logger.info("Assigning synchronous standby status to %s", picked)
                 self.state_handler.config.set_synchronous_standby(picked)
 
-                if picked and picked != '*' and not allow_promote:
+                if picked and picked[0] != '*' and set(allow_promote) != set(picked) and not allow_promote:
                     # Wait for PostgreSQL to enable synchronous mode and see if we can immediately set sync_standby
                     time.sleep(2)
-                    picked, allow_promote = self.state_handler.pick_synchronous_standby(self.cluster)
-                if allow_promote:
+                    _, allow_promote = self.state_handler.pick_synchronous_standby(self.cluster,
+                                                                                   sync_node_count,
+                                                                                   self.patroni.config[
+                                                                                       'maximum_lag_on_syncnode'])
+                if allow_promote and set(allow_promote) != set(sync_common):
                     try:
                         cluster = self.dcs.get_cluster()
                     except DCSError:
@@ -466,18 +495,18 @@ class Ha(object):
                     if cluster.sync.leader and cluster.sync.leader != self.state_handler.name:
                         logger.info("Synchronous replication key updated by someone else")
                         return
-                    if not self.dcs.write_sync_state(self.state_handler.name, picked, index=cluster.sync.index):
+                    if not self.dcs.write_sync_state(self.state_handler.name, allow_promote, index=cluster.sync.index):
                         logger.info("Synchronous replication key updated by someone else")
                         return
-                    logger.info("Synchronous standby status assigned to %s", picked)
+                    logger.info("Synchronous standby status assigned to %s", allow_promote)
         else:
             if self.cluster.sync.leader and self.dcs.delete_sync_state(index=self.cluster.sync.index):
                 logger.info("Disabled synchronous replication")
-            self.state_handler.config.set_synchronous_standby(None)
+            self.state_handler.config.set_synchronous_standby([])
 
     def is_sync_standby(self, cluster):
         return cluster.leader and cluster.sync.leader == cluster.leader.name \
-            and cluster.sync.sync_standby == self.state_handler.name
+            and self.state_handler.name in cluster.sync.members
 
     def while_not_sync_standby(self, func):
         """Runs specified action while trying to make sure that the node is not assigned synchronous standby status.
@@ -522,17 +551,19 @@ class Ha(object):
         if master_timeline == 1:
             if cluster_history:
                 self.dcs.set_history_value('[]')
-        elif not cluster_history or cluster_history[-1][0] != master_timeline - 1 or len(cluster_history[-1]) != 4:
-            cluster_history = {l[0]: l for l in cluster_history or []}
+        elif not cluster_history or cluster_history[-1][0] != master_timeline - 1 or len(cluster_history[-1]) != 5:
+            cluster_history = {line[0]: line for line in cluster_history or []}
             history = self.state_handler.get_history(master_timeline)
-            if history:
+            if history and self.cluster.config:
                 history = history[-self.cluster.config.max_timelines_history:]
                 for line in history:
                     # enrich current history with promotion timestamps stored in DCS
                     if len(line) == 3 and line[0] in cluster_history \
-                            and len(cluster_history[line[0]]) == 4 \
+                            and len(cluster_history[line[0]]) >= 4 \
                             and cluster_history[line[0]][1] == line[1]:
                         line.append(cluster_history[line[0]][3])
+                        if len(cluster_history[line[0]]) == 5:
+                            line.append(cluster_history[line[0]][4])
                 self.dcs.set_history_value(json.dumps(history, separators=(',', ':')))
 
     def enforce_follow_remote_master(self, message):
@@ -540,13 +571,27 @@ class Ha(object):
         return self.follow(demote_reason, message)
 
     def enforce_master_role(self, message, promote_message):
-        if not self.is_paused() and not self.watchdog.is_running and not self.watchdog.activate():
-            if self.state_handler.is_leader():
-                self.demote('immediate')
-                return 'Demoting self because watchdog could not be activated'
-            else:
-                self.release_leader_key_voluntarily()
-                return 'Not promoting self because watchdog could not be activated'
+        """
+        Ensure the node that has won the race for the leader key meets criteria
+        for promoting its PG server to the 'master' role.
+        """
+        if not self.is_paused():
+            if not self.watchdog.is_running and not self.watchdog.activate():
+                if self.state_handler.is_leader():
+                    self.demote('immediate')
+                    return 'Demoting self because watchdog could not be activated'
+                else:
+                    self.release_leader_key_voluntarily()
+                    return 'Not promoting self because watchdog could not be activated'
+
+            with self._async_response:
+                if self._async_response.result is False:
+                    logger.warning("Releasing the leader key voluntarily because the pre-promote script failed")
+                    self._released_leader_key_timestamp = time.time()
+                    self.release_leader_key_voluntarily()
+                    # discard the result of the failed pre-promote script to be able to re-try promote
+                    self._async_response.reset()
+                    return 'Promotion cancelled because the pre-promote script failed'
 
         if self.state_handler.is_leader():
             # Inform the state handler about its master role.
@@ -566,17 +611,16 @@ class Ha(object):
                     # Somebody else updated sync state, it may be due to us losing the lock. To be safe, postpone
                     # promotion until next cycle. TODO: trigger immediate retry of run_cycle
                     return 'Postponing promotion because synchronous replication state was updated by somebody else'
-                self.state_handler.config.set_synchronous_standby('*' if self.is_synchronous_mode_strict() else None)
+                self.state_handler.config.set_synchronous_standby(['*'] if self.is_synchronous_mode_strict() else [])
             if self.state_handler.role != 'master':
-                self.set_leader_access_is_restricted(self.cluster.has_permanent_logical_slots(self.state_handler.name))
-
                 def on_success():
                     self._rewind.reset_state()
                     logger.info("cleared rewind state after becoming the leader")
 
+                with self._async_response:
+                    self._async_response.reset()
                 self._async_executor.try_run_async('promote', self.state_handler.promote,
-                                                   args=(self.dcs.loop_wait, on_success,
-                                                         self._leader_access_is_restricted))
+                                                   args=(self.dcs.loop_wait, self._async_response, on_success))
             return promote_message
 
     def fetch_node_status(self, member):
@@ -606,14 +650,13 @@ class Ha(object):
         :param wal_position: Current wal position.
         :returns True when node is lagging
         """
-        lag = (self.cluster.last_leader_operation or 0) - wal_position
+        lag = (self.cluster.last_lsn or 0) - wal_position
         return lag > self.patroni.config.get('maximum_lag_on_failover', 0)
 
     def _is_healthiest_node(self, members, check_replication_lag=True):
         """This method tries to determine whether I am healthy enough to became a new leader candidate or not."""
 
-        # We don't call `last_operation()` here because it returns a string
-        _, my_wal_position, _ = self.state_handler.timeline_wal_position()
+        my_wal_position = self.state_handler.last_operation()
         if check_replication_lag and self.is_lagging(my_wal_position):
             logger.info('My wal position exceeds maximum replication lag')
             return False  # Too far behind last reported wal position on master
@@ -643,16 +686,21 @@ class Ha(object):
                         logger.info('Ignoring the former leader being ahead of us')
         return True
 
-    def is_failover_possible(self, members):
+    def is_failover_possible(self, members, check_synchronous=True, cluster_lsn=None):
         ret = False
         cluster_timeline = self.cluster.timeline
         members = [m for m in members if m.name != self.state_handler.name and not m.nofailover and m.api_url]
+        if check_synchronous and self.is_synchronous_mode():
+            members = [m for m in members if self.cluster.sync.matches(m.name)]
         if members:
             for st in self.fetch_nodes_statuses(members):
                 not_allowed_reason = st.failover_limitation()
                 if not_allowed_reason:
                     logger.info('Member %s is %s', st.member.name, not_allowed_reason)
-                elif self.is_lagging(st.wal_position):
+                elif not isinstance(st.wal_position, six.integer_types):
+                    logger.info('Member %s does not report wal_position', st.member.name)
+                elif cluster_lsn and st.wal_position < cluster_lsn or\
+                        not cluster_lsn and self.is_lagging(st.wal_position):
                     logger.info('Member %s exceeds maximum replication lag', st.member.name)
                 elif self.check_timeline() and (not st.timeline or st.timeline < cluster_timeline):
                     logger.info('Timeline %s of member %s is behind the cluster timeline %s',
@@ -711,6 +759,10 @@ class Ha(object):
         return self._is_healthiest_node(members, check_replication_lag=False)
 
     def is_healthiest_node(self):
+        if time.time() - self._released_leader_key_timestamp < self.dcs.ttl:
+            logger.info('backoff: skip leader race after pre_promote script failure and releasing the lock voluntarily')
+            return False
+
         if self.is_paused() and not self.patroni.nofailover and \
                 self.cluster.failover and not self.cluster.failover.scheduled_at:
             ret = self.manual_failover_process_no_leader()
@@ -720,8 +772,10 @@ class Ha(object):
         if self.state_handler.is_starting():  # postgresql still starting up is unhealthy
             return False
 
-        if self.state_handler.is_leader():  # leader is always the healthiest
-            return True
+        if self.state_handler.is_leader():
+            # in pause leader is the healthiest only when no initialize or sysid matches with initialize!
+            return not self.is_paused() or not self.cluster.initialize\
+                    or self.state_handler.sysid == self.cluster.initialize
 
         if self.is_paused():
             return False
@@ -730,9 +784,14 @@ class Ha(object):
             return False
 
         if self.cluster.failover:
+            # When doing a switchover in synchronous mode only synchronous nodes and former leader are allowed to race
+            if self.is_synchronous_mode() and self.cluster.failover.leader and \
+                    self.cluster.failover.candidate and not self.cluster.sync.matches(self.state_handler.name):
+                return False
             return self.manual_failover_process_no_leader()
 
         if not self.watchdog.is_healthy:
+            logger.warning('Watchdog device is not usable')
             return False
 
         # When in sync mode, only last known master and sync standby are allowed to promote automatically.
@@ -748,13 +807,13 @@ class Ha(object):
 
         return self._is_healthiest_node(members.values())
 
-    def _delete_leader(self):
+    def _delete_leader(self, last_lsn=None):
         self.set_is_leader(False)
-        self.dcs.delete_leader()
+        self.dcs.delete_leader(last_lsn)
         self.dcs.reset_cluster()
 
-    def release_leader_key_voluntarily(self):
-        self._delete_leader()
+    def release_leader_key_voluntarily(self, last_lsn=None):
+        self._delete_leader(last_lsn)
         self.touch_member()
         logger.info("Leader key released")
 
@@ -776,22 +835,44 @@ class Ha(object):
             'immediate-nolock': dict(stop='immediate', checkpoint=False, release=False, offline=False, async_req=True),
         }[mode]
 
+        logger.info('Demoting self (%s)', mode)
+
         self._rewind.trigger_check_diverged_lsn()
+
+        status = {'released': False}
+
+        def on_shutdown(checkpoint_location):
+            # Postmaster is still running, but pg_control already reports clean "shut down".
+            # It could happen if Postgres is still archiving the backlog of WAL files.
+            # If we know that there are replicas that received the shutdown checkpoint
+            # location, we can remove the leader key and allow them to start leader race.
+            if self.is_failover_possible(self.cluster.members, cluster_lsn=checkpoint_location):
+                self.state_handler.set_role('demoted')
+                with self._async_executor:
+                    self.release_leader_key_voluntarily(checkpoint_location)
+                    status['released'] = True
+
         self.state_handler.stop(mode_control['stop'], checkpoint=mode_control['checkpoint'],
                                 on_safepoint=self.watchdog.disable if self.watchdog.is_running else None,
+                                on_shutdown=on_shutdown if mode_control['release'] else None,
                                 stop_timeout=self.master_stop_timeout())
         self.state_handler.set_role('demoted')
         self.set_is_leader(False)
 
         if mode_control['release']:
-            with self._async_executor:
-                self.release_leader_key_voluntarily()
+            if not status['released']:
+                checkpoint_location = self.state_handler.latest_checkpoint_location() if mode == 'graceful' else None
+                with self._async_executor:
+                    self.release_leader_key_voluntarily(checkpoint_location)
             time.sleep(2)  # Give a time to somebody to take the leader lock
         if mode_control['offline']:
             node_to_follow, leader = None, None
         else:
-            cluster = self.dcs.get_cluster()
-            node_to_follow, leader = self._get_node_to_follow(cluster), cluster.leader
+            try:
+                cluster = self.dcs.get_cluster()
+                node_to_follow, leader = self._get_node_to_follow(cluster), cluster.leader
+            except Exception:
+                node_to_follow, leader = None, None
 
         # FIXME: with mode offline called from DCS exception handler and handle_long_action_in_progress
         # there could be an async action already running, calling follow from here will lead
@@ -800,7 +881,7 @@ class Ha(object):
             self._async_executor.try_run_async('starting after demotion', self.state_handler.follow, (node_to_follow,))
         else:
             if self.is_synchronous_mode():
-                self.state_handler.config.set_synchronous_standby(None)
+                self.state_handler.config.set_synchronous_standby([])
             if self._rewind.rewind_or_reinitialize_needed_and_possible(leader):
                 return False  # do not start postgres, but run pg_rewind on the next iteration
             self.state_handler.follow(node_to_follow)
@@ -861,7 +942,7 @@ class Ha(object):
                 else:
                     if self.is_synchronous_mode():
                         if failover.candidate and not self.cluster.sync.matches(failover.candidate):
-                            logger.warning('Failover candidate=%s does not match with sync_standby=%s',
+                            logger.warning('Failover candidate=%s does not match with sync_standbys=%s',
                                            failover.candidate, self.cluster.sync.sync_standby)
                             members = []
                         else:
@@ -869,7 +950,7 @@ class Ha(object):
                     else:
                         members = [m for m in self.cluster.members
                                    if not failover.candidate or m.name == failover.candidate]
-                    if self.is_failover_possible(members):  # check that there are healthy members
+                    if self.is_failover_possible(members, False):  # check that there are healthy members
                         ret = self._async_executor.try_run_async('manual failover: demote', self.demote, ('graceful',))
                         return ret or 'manual failover: demoting myself'
                     else:
@@ -899,9 +980,9 @@ class Ha(object):
                 self.load_cluster_from_dcs()
 
                 if self.is_standby_cluster():
-                    # standby leader disappeared, and this is a healthiest
+                    # standby leader disappeared, and this is the healthiest
                     # replica, so it should become a new standby leader.
-                    # This imply that we need to start following a remote master
+                    # This implies we need to start following a remote master
                     msg = 'promoted self to a standby leader by acquiring session lock'
                     return self.enforce_follow_remote_master(msg)
                 else:
@@ -934,31 +1015,26 @@ class Ha(object):
                 self._delete_leader()
                 return 'removed leader lock because postgres is not running as master'
 
-            if self.state_handler.is_leader() and self._leader_access_is_restricted:
-                self.state_handler.slots_handler.sync_replication_slots(self.cluster)
-                self.state_handler.call_nowait(ACTION_ON_ROLE_CHANGE)
-                self.set_leader_access_is_restricted(False)
-
             if self.update_lock(True):
                 msg = self.process_manual_failover_from_leader()
                 if msg is not None:
                     return msg
 
                 # check if the node is ready to be used by pg_rewind
-                self._rewind.ensure_checkpoint_after_promote()
+                self._rewind.ensure_checkpoint_after_promote(self.wakeup)
 
                 if self.is_standby_cluster():
                     # in case of standby cluster we don't really need to
                     # enforce anything, since the leader is not a master.
                     # So just remind the role.
-                    msg = 'no action.  i am the standby leader with the lock' \
+                    msg = 'no action. I am ({0}), the standby leader with the lock'.format(self.state_handler.name) \
                           if self.state_handler.role == 'standby_leader' else \
                           'promoted self to a standby leader because i had the session lock'
                     return self.enforce_follow_remote_master(msg)
                 else:
                     return self.enforce_master_role(
-                        'no action.  i am the leader with the lock',
-                        'promoted self to leader because i had the session lock'
+                        'no action. I am ({0}), the leader with the lock'.format(self.state_handler.name),
+                        'promoted self to leader because I had the session lock'
                     )
             else:
                 # Either there is no connection to DCS or someone else acquired the lock
@@ -971,12 +1047,15 @@ class Ha(object):
                 else:
                     return 'not promoting because failed to update leader lock in DCS'
         else:
-            logger.info('does not have lock')
+            logger.debug('does not have lock')
+        lock_owner = self.cluster.leader and self.cluster.leader.name
         if self.is_standby_cluster():
-            return self.follow('cannot be a real master in standby cluster',
-                               'no action.  i am a secondary and i am following a standby leader', refresh=False)
-        return self.follow('demoting self because i do not have the lock and i was a leader',
-                           'no action.  i am a secondary and i am following a leader', refresh=False)
+            return self.follow('cannot be a real primary in a standby cluster',
+                               'no action. I am ({0}), a secondary, and following a standby leader ({1})'.format(
+                                    self.state_handler.name, lock_owner), refresh=False)
+        return self.follow('demoting self because I do not have the lock and I was a leader',
+                           'no action. I am ({0}), a secondary, and following a leader ({1})'.format(
+                                self.state_handler.name, lock_owner), refresh=False)
 
     def evaluate_scheduled_restart(self):
         if self._async_executor.busy:  # Restart already in progress
@@ -1119,10 +1198,28 @@ class Ha(object):
         self._async_executor.run_async(self._do_reinitialize, args=(self.cluster, ))
 
     def handle_long_action_in_progress(self):
+        """
+        Figure out what to do with the task AsyncExecutor is performing.
+        """
         if self.has_lock() and self.update_lock():
+            if self._async_executor.scheduled_action == 'doing crash recovery in a single user mode':
+                time_left = self.patroni.config['master_start_timeout'] - (time.time() - self._crash_recovery_started)
+                if time_left <= 0 and self.is_failover_possible(self.cluster.members):
+                    logger.info("Demoting self because crash recovery is taking too long")
+                    self.state_handler.cancellable.cancel(True)
+                    self.demote('immediate')
+                    return 'terminated crash recovery because of startup timeout'
+
             return 'updated leader lock during ' + self._async_executor.scheduled_action
-        elif not self.state_handler.bootstrapping:
-            # Don't have lock, make sure we are not starting up a master in the background
+        elif not self.state_handler.bootstrapping and not self.is_paused():
+            # Don't have lock, make sure we are not promoting or starting up a master in the background
+            if self._async_executor.scheduled_action == 'promote':
+                with self._async_response:
+                    cancel = self._async_response.cancel()
+                if cancel:
+                    self.state_handler.cancellable.cancel()
+                    return 'lost leader before promote'
+
             if self.state_handler.role == 'master':
                 logger.info("Demoting master during " + self._async_executor.scheduled_action)
                 if self._async_executor.scheduled_action == 'restart':
@@ -1133,7 +1230,6 @@ class Ha(object):
                             self.state_handler.terminate_starting_postmaster(postmaster=task.result)
                 self.demote('immediate-nolock')
                 return 'lost leader lock during ' + self._async_executor.scheduled_action
-
         if self.cluster.is_unlocked():
             logger.info('not healthy enough for leader race')
 
@@ -1155,9 +1251,6 @@ class Ha(object):
                 self._delete_leader()
                 return 'removed leader key after trying and failing to start postgres'
             return 'failed to start postgres'
-        self._crash_recovery_executed = False
-        if self._rewind.executed and not self._rewind.failed:
-            self._rewind.reset_state()
         return None
 
     def cancel_initialization(self):
@@ -1165,29 +1258,31 @@ class Ha(object):
         self.dcs.cancel_initialization()
         self.state_handler.stop('immediate', stop_timeout=self.patroni.config['retry_timeout'])
         self.state_handler.move_data_directory()
-        raise PatroniException('Failed to bootstrap cluster')
+        raise PatroniFatalException('Failed to bootstrap cluster')
 
     def post_bootstrap(self):
+        with self._async_response:
+            result = self._async_response.result
         # bootstrap has failed if postgres is not running
-        if not self.state_handler.is_running() or self._post_bootstrap_task.result is False:
+        if not self.state_handler.is_running() or result is False:
             self.cancel_initialization()
 
-        if self._post_bootstrap_task.result is None:
+        if result is None:
             if not self.state_handler.is_leader():
                 return 'waiting for end of recovery after bootstrap'
 
             self.state_handler.set_role('master')
             ret = self._async_executor.try_run_async('post_bootstrap', self.state_handler.bootstrap.post_bootstrap,
-                                                     args=(self.patroni.config['bootstrap'], self._post_bootstrap_task))
+                                                     args=(self.patroni.config['bootstrap'], self._async_response))
             return ret or 'running post_bootstrap'
 
         self.state_handler.bootstrapping = False
         if not self.watchdog.activate():
             logger.error('Cancelling bootstrap because watchdog activation failed')
             self.cancel_initialization()
+        self._rewind.ensure_checkpoint_after_promote(self.wakeup)
         self.dcs.initialize(create_new=(self.cluster.initialize is None), sysid=self.state_handler.sysid)
         self.dcs.set_config_value(json.dumps(self.patroni.config.dynamic_configuration, separators=(',', ':')))
-        self.state_handler.slots_handler.sync_replication_slots(self.cluster)
         self.dcs.take_leader()
         self.set_is_leader(True)
         self.state_handler.call_nowait(ACTION_ON_START)
@@ -1243,8 +1338,12 @@ class Ha(object):
     def _run_cycle(self):
         dcs_failed = False
         try:
-            self.state_handler.reset_cluster_info_state()
-            self.load_cluster_from_dcs()
+            try:
+                self.load_cluster_from_dcs()
+                self.state_handler.reset_cluster_info_state(self.cluster, self.patroni.nofailover)
+            except Exception:
+                self.state_handler.reset_cluster_info_state(None, self.patroni.nofailover)
+                raise
 
             if self.is_paused():
                 self.watchdog.disable()
@@ -1276,12 +1375,24 @@ class Ha(object):
             if self.state_handler.bootstrapping:
                 return self.post_bootstrap()
 
-            if self.recovering and not self._rewind.is_needed:
+            if self.recovering:
                 self.recovering = False
-                # Check if we tried to recover and failed
-                msg = self.post_recover()
-                if msg is not None:
-                    return msg
+
+                if not self._rewind.is_needed:
+                    # Check if we tried to recover from postgres crash and failed
+                    msg = self.post_recover()
+                    if msg is not None:
+                        return msg
+
+                # Reset some states after postgres successfully started up
+                self._crash_recovery_executed = False
+                if self._rewind.executed and not self._rewind.failed:
+                    self._rewind.reset_state()
+
+                # The Raft cluster without a quorum takes a bit of time to stabilize.
+                # Therefore we want to postpone the leader race if we just started up.
+                if self.cluster.is_unlocked() and self.dcs.__class__.__name__ == 'Raft':
+                    return 'started as a secondary'
 
             # is data directory empty?
             if self.state_handler.data_directory_empty():
@@ -1295,6 +1406,8 @@ class Ha(object):
                     self.release_leader_key_voluntarily()
                     return 'released leader key voluntarily as data dir empty and currently leader'
 
+                if self.is_paused():
+                    return 'running with empty data directory'
                 return self.bootstrap()  # new node
             else:
                 # check if we are allowed to join
@@ -1306,9 +1419,16 @@ class Ha(object):
 
                 if self.sysid_valid(self.cluster.initialize):
                     if self.cluster.initialize != data_sysid:
-                        logger.fatal("system ID mismatch, node %s belongs to a different cluster: %s != %s",
-                                     self.state_handler.name, self.cluster.initialize, data_sysid)
-                        sys.exit(1)
+                        if self.is_paused():
+                            logger.warning('system ID has changed while in paused mode. Patroni will exit when resuming'
+                                           ' unless system ID is reset: %s != %s', self.cluster.initialize, data_sysid)
+                            if self.has_lock():
+                                self.release_leader_key_voluntarily()
+                                return 'released leader key voluntarily due to the system ID mismatch'
+                        else:
+                            logger.fatal('system ID mismatch, node %s belongs to a different cluster: %s != %s',
+                                         self.state_handler.name, self.cluster.initialize, data_sysid)
+                            sys.exit(1)
                 elif self.cluster.is_unlocked() and not self.is_paused():
                     # "bootstrap", but data directory is not empty
                     if not self.state_handler.cb_called and self.state_handler.is_running() \
@@ -1321,6 +1441,7 @@ class Ha(object):
 
             if not self.state_handler.is_healthy():
                 if self.is_paused():
+                    self.state_handler.set_state('stopped')
                     if self.has_lock():
                         self._delete_leader()
                         return 'removed leader lock because postgres is not running'
@@ -1333,25 +1454,35 @@ class Ha(object):
                             (self._rewind.is_needed and self._rewind.can_rewind_or_reinitialize_allowed):
                         return 'postgres is not running'
 
+                if self.state_handler.state in ('running', 'starting'):
+                    self.state_handler.set_state('crashed')
                 # try to start dead postgres
                 return self.recover()
 
             try:
                 if self.cluster.is_unlocked():
-                    return self.process_unhealthy_cluster()
+                    ret = self.process_unhealthy_cluster()
                 else:
                     msg = self.process_healthy_cluster()
-                    return self.evaluate_scheduled_restart() or msg
+                    ret = self.evaluate_scheduled_restart() or msg
             finally:
                 # we might not have a valid PostgreSQL connection here if another thread
                 # stops PostgreSQL, therefore, we only reload replication slots if no
                 # asynchronous processes are running (should be always the case for the master)
                 if not self._async_executor.busy and not self.state_handler.is_starting():
-                    self.state_handler.slots_handler.sync_replication_slots(self.cluster)
+                    create_slots = self.state_handler.slots_handler.sync_replication_slots(self.cluster,
+                                                                                           self.patroni.nofailover)
                     if not self.state_handler.cb_called:
                         if not self.state_handler.is_leader():
                             self._rewind.trigger_check_diverged_lsn()
                         self.state_handler.call_nowait(ACTION_ON_START)
+                    if create_slots and self.cluster.leader:
+                        err = self._async_executor.try_run_async('copy_logical_slots',
+                                                                 self.state_handler.slots_handler.copy_logical_slots,
+                                                                 args=(self.cluster.leader, create_slots))
+                        if not err:
+                            ret = 'Copying logical slots {0} from the primary'.format(create_slots)
+            return ret
         except DCSError:
             dcs_failed = True
             logger.error('Error communicating with DCS')
@@ -1359,7 +1490,7 @@ class Ha(object):
                 self.demote('offline')
                 return 'demoted self because DCS is not accessible and i was a leader'
             return 'DCS is not accessible'
-        except (psycopg2.Error, PostgresConnectionException):
+        except (psycopg.Error, PostgresConnectionException):
             return 'Error communicating with PostgreSQL. Will try again later'
         finally:
             if not dcs_failed:
@@ -1367,8 +1498,14 @@ class Ha(object):
 
     def run_cycle(self):
         with self._async_executor:
-            info = self._run_cycle()
-            return (self.is_paused() and 'PAUSE: ' or '') + info
+            try:
+                info = self._run_cycle()
+                return (self.is_paused() and 'PAUSE: ' or '') + info
+            except PatroniFatalException:
+                raise
+            except Exception:
+                logger.exception('Unexpected exception')
+                return 'Unexpected exception raised, please report it as a BUG'
 
     def shutdown(self):
         if self.is_paused():
@@ -1376,15 +1513,33 @@ class Ha(object):
             self.watchdog.disable()
         elif not self._join_aborted:
             # FIXME: If stop doesn't reach safepoint quickly enough keepalive is triggered. If shutdown checkpoint
-            # takes longer than ttl, then leader key is lost and replication might not have sent out all xlog.
+            # takes longer than ttl, then leader key is lost and replication might not have sent out all WAL.
             # This might not be the desired behavior of users, as a graceful shutdown of the host can mean lost data.
             # We probably need to something smarter here.
             disable_wd = self.watchdog.disable if self.watchdog.is_running else None
+
+            status = {'deleted': False}
+
+            def _on_shutdown(checkpoint_location):
+                if self.is_leader():
+                    # Postmaster is still running, but pg_control already reports clean "shut down".
+                    # It could happen if Postgres is still archiving the backlog of WAL files.
+                    # If we know that there are replicas that received the shutdown checkpoint
+                    # location, we can remove the leader key and allow them to start leader race.
+                    if self.is_failover_possible(self.cluster.members, cluster_lsn=checkpoint_location):
+                        self.dcs.delete_leader(checkpoint_location)
+                        status['deleted'] = True
+                    else:
+                        self.dcs.write_leader_optime(checkpoint_location)
+
+            on_shutdown = _on_shutdown if self.is_leader() else None
             self.while_not_sync_standby(lambda: self.state_handler.stop(checkpoint=False, on_safepoint=disable_wd,
+                                                                        on_shutdown=on_shutdown,
                                                                         stop_timeout=self.master_stop_timeout()))
             if not self.state_handler.is_running():
-                if self.has_lock():
-                    self.dcs.delete_leader()
+                if self.is_leader() and not status['deleted']:
+                    checkpoint_location = self.state_handler.latest_checkpoint_location()
+                    self.dcs.delete_leader(checkpoint_location)
                 self.touch_member()
             else:
                 # XXX: what about when Patroni is started as the wrong user that has access to the watchdog device
@@ -1395,7 +1550,7 @@ class Ha(object):
 
     def watch(self, timeout):
         # watch on leader key changes if the postgres is running and leader is known and current node is not lock owner
-        if self._async_executor.busy or self.cluster.is_unlocked() or self.has_lock(False):
+        if self._async_executor.busy or not self.cluster or self.cluster.is_unlocked() or self.has_lock(False):
             leader_index = None
         else:
             leader_index = self.cluster.leader.index

patroni/log.py

@@ -166,6 +166,8 @@ class PatroniLogger(Thread):
             self._root_logger.addHandler(self._queue_handler)
             self._root_logger.removeHandler(self._proxy_handler)
 
+        prev_record = None
+
         while True:
             self._close_old_handlers()
 
@@ -173,7 +175,18 @@ class PatroniLogger(Thread):
             if record is None:
                 break
 
-            self.log_handler.handle(record)
+            if self._root_logger.level == logging.INFO:
+                if record.msg.startswith('Lock owner: '):
+                    prev_record, record = record, None
+                else:
+                    if prev_record and prev_record.thread == record.thread:
+                        if not (record.msg.startswith('no action. ') or record.msg.startswith('PAUSE: no action')):
+                            self.log_handler.handle(prev_record)
+                        prev_record = None
+
+            if record:
+                self.log_handler.handle(record)
+
             self._queue_handler.queue.task_done()
 
     def shutdown(self):

patroni/postgresql/__init__.py

@@ -1,25 +1,30 @@
 import logging
 import os
-import psycopg2
+import re
 import shlex
 import shutil
+import six
 import subprocess
 import time
 
 from contextlib import contextmanager
 from copy import deepcopy
-from patroni.postgresql.callback_executor import CallbackExecutor
-from patroni.postgresql.bootstrap import Bootstrap
-from patroni.postgresql.cancellable import CancellableSubprocess
-from patroni.postgresql.config import ConfigHandler
-from patroni.postgresql.connection import Connection, get_connection_cursor
-from patroni.postgresql.misc import parse_history, postgres_major_version_to_int
-from patroni.postgresql.postmaster import PostmasterProcess
-from patroni.postgresql.slots import SlotsHandler
-from patroni.exceptions import PostgresConnectionException
-from patroni.utils import Retry, RetryFailedError, polling_loop, data_directory_is_empty, parse_int
-from threading import current_thread, Lock
+from datetime import datetime
+from dateutil import tz
 from psutil import TimeoutExpired
+from threading import current_thread, Lock
+
+from .bootstrap import Bootstrap
+from .callback_executor import CallbackExecutor
+from .cancellable import CancellableSubprocess
+from .config import ConfigHandler, mtime
+from .connection import Connection, get_connection_cursor
+from .misc import parse_history, parse_lsn, postgres_major_version_to_int
+from .postmaster import PostmasterProcess
+from .slots import SlotsHandler
+from .. import psycopg
+from ..exceptions import PostgresConnectionException
+from ..utils import Retry, RetryFailedError, polling_loop, data_directory_is_empty, parse_int
 
 
 logger = logging.getLogger(__name__)
@@ -46,6 +51,16 @@ def null_context():
 
 class Postgresql(object):
 
+    POSTMASTER_START_TIME = "pg_catalog.pg_postmaster_start_time()"
+    TL_LSN = ("CASE WHEN pg_catalog.pg_is_in_recovery() THEN 0 "
+              "ELSE ('x' || pg_catalog.substr(pg_catalog.pg_{0}file_name("
+              "pg_catalog.pg_current_{0}_{1}()), 1, 8))::bit(32)::int END, "  # master timeline
+              "CASE WHEN pg_catalog.pg_is_in_recovery() THEN 0 "
+              "ELSE pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_current_{0}_{1}(), '0/0')::bigint END, "  # write_lsn
+              "pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_last_{0}_replay_{1}(), '0/0')::bigint, "
+              "pg_catalog.pg_{0}_{1}_diff(COALESCE(pg_catalog.pg_last_{0}_receive_{1}(), '0/0'), '0/0')::bigint, "
+              "pg_catalog.pg_is_in_recovery() AND pg_catalog.pg_is_{0}_replay_paused()")
+
     def __init__(self, config):
         self.name = config['name']
         self.scope = config['scope']
@@ -89,15 +104,19 @@ class Postgresql(object):
         self._state_entry_timestamp = None
 
         self._cluster_info_state = {}
+        self._has_permanent_logical_slots = True
+        self._enforce_hot_standby_feedback = False
         self._cached_replica_timeline = None
 
         # Last known running process
         self._postmaster_proc = None
 
-        if self.is_running():
+        if self.is_running():  # we are "joining" already running postgres
             self.set_state('running')
             self.set_role('master' if self.is_leader() else 'replica')
-            self.config.write_postgresql_conf()  # we are "joining" already running postgres
+            # postpone writing postgresql.conf for 12+ because recovery parameters are not yet known
+            if self.major_version < 120000 or self.is_leader():
+                self.config.write_postgresql_conf()
             hba_saved = self.config.replace_pg_hba()
             ident_saved = self.config.replace_pg_ident()
             if hba_saved or ident_saved:
@@ -125,6 +144,10 @@ class Postgresql(object):
     def callback(self):
         return self.config.get('callbacks') or {}
 
+    @property
+    def wal_dir(self):
+        return os.path.join(self._data_dir, 'pg_' + self.wal_name)
+
     @property
     def wal_name(self):
         return 'wal' if self._major_version >= 100000 else 'xlog'
@@ -135,17 +158,21 @@ class Postgresql(object):
 
     @property
     def cluster_info_query(self):
-        pg_control_timeline = 'timeline_id FROM pg_catalog.pg_control_checkpoint()' \
-                if self._major_version >= 90600 and self.role == 'standby_leader' else '0'
-        return ("SELECT CASE WHEN pg_catalog.pg_is_in_recovery() THEN 0 "
-                "ELSE ('x' || pg_catalog.substr(pg_catalog.pg_{0}file_name("
-                "pg_catalog.pg_current_{0}_{1}()), 1, 8))::bit(32)::int END, "
-                "CASE WHEN pg_catalog.pg_is_in_recovery() THEN GREATEST("
-                " pg_catalog.pg_{0}_{1}_diff(COALESCE("
-                "pg_catalog.pg_last_{0}_receive_{1}(), '0/0'), '0/0')::bigint,"
-                " pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_last_{0}_replay_{1}(), '0/0')::bigint)"
-                "ELSE pg_catalog.pg_{0}_{1}_diff(pg_catalog.pg_current_{0}_{1}(), '0/0')::bigint "
-                "END, {2}").format(self.wal_name, self.lsn_name, pg_control_timeline)
+        if self._major_version >= 90600:
+            extra = "(SELECT pg_catalog.json_agg(s.*) FROM (SELECT slot_name, slot_type as type, datoid::bigint, " +\
+                    "plugin, catalog_xmin, pg_catalog.pg_wal_lsn_diff(confirmed_flush_lsn, '0/0')::bigint" + \
+                    " AS confirmed_flush_lsn FROM pg_catalog.pg_get_replication_slots()) AS s)"\
+                            if self._has_permanent_logical_slots and self._major_version >= 110000 else "NULL"
+            extra = (", CASE WHEN latest_end_lsn IS NULL THEN NULL ELSE received_tli END,"
+                     " slot_name, conninfo, {0} FROM pg_catalog.pg_stat_get_wal_receiver()").format(extra)
+            if self.role == 'standby_leader':
+                extra = "timeline_id" + extra + ", pg_catalog.pg_control_checkpoint()"
+            else:
+                extra = "0" + extra
+        else:
+            extra = "0, NULL, NULL, NULL, NULL"
+
+        return ("SELECT " + self.TL_LSN + ", {2}").format(self.wal_name, self.lsn_name, extra)
 
     def _version_file_exists(self):
         return not self.data_directory_empty() and os.path.isfile(self._version_file)
@@ -239,13 +266,13 @@ class Postgresql(object):
             cursor = self._connection.cursor()
             cursor.execute(sql, params)
             return cursor
-        except psycopg2.Error as e:
+        except psycopg.Error as e:
             if cursor and cursor.connection.closed == 0:
                 # When connected via unix socket, psycopg2 can't recoginze 'connection lost'
                 # and leaves `_cursor_holder.connection.closed == 0`, but psycopg2.OperationalError
                 # is still raised (what is correct). It doesn't make sense to continiue with existing
                 # connection and we will close it, to avoid its reuse by the `cursor` method.
-                if isinstance(e, psycopg2.OperationalError):
+                if isinstance(e, psycopg.OperationalError):
                     self._connection.close()
                 else:
                     raise e
@@ -283,14 +310,41 @@ class Postgresql(object):
             replica_methods = self.create_replica_methods
         return any(self.replica_method_can_work_without_replication_connection(m) for m in replica_methods)
 
-    def reset_cluster_info_state(self):
+    @property
+    def enforce_hot_standby_feedback(self):
+        return self._enforce_hot_standby_feedback
+
+    def set_enforce_hot_standby_feedback(self, value):
+        # If we enable or disable the hot_standby_feedback we need to update postgresql.conf and reload
+        if self._enforce_hot_standby_feedback != value:
+            self._enforce_hot_standby_feedback = value
+            if self.is_running():
+                self.config.write_postgresql_conf()
+                self.reload()
+
+    def reset_cluster_info_state(self, cluster, nofailover=None):
         self._cluster_info_state = {}
+        if cluster and cluster.config and cluster.config.modify_index:
+            self._has_permanent_logical_slots =\
+                cluster.has_permanent_logical_slots(self.name, nofailover, self.major_version)
+
+            # We want to enable hot_standby_feedback if the replica is supposed
+            # to have a logical slot or in case if it is the cascading replica.
+            self.set_enforce_hot_standby_feedback(
+                self._has_permanent_logical_slots or
+                cluster.should_enforce_hot_standby_feedback(self.name, nofailover, self.major_version))
 
     def _cluster_info_state_get(self, name):
         if not self._cluster_info_state:
             try:
                 result = self._is_leader_retry(self._query, self.cluster_info_query).fetchone()
-                self._cluster_info_state = dict(zip(['timeline', 'wal_position', 'pg_control_timeline'], result))
+                cluster_info_state = dict(zip(['timeline', 'wal_position', 'replayed_location',
+                                               'received_location', 'replay_paused', 'pg_control_timeline',
+                                               'received_tli', 'slot_name', 'conninfo', 'slots'], result))
+                if self._has_permanent_logical_slots:
+                    cluster_info_state['slots'] =\
+                        self.slots_handler.process_permanent_slots(cluster_info_state['slots'])
+                self._cluster_info_state = cluster_info_state
             except RetryFailedError as e:  # SELECT failed two times
                 self._cluster_info_state = {'error': str(e)}
                 if not self.is_starting() and self.pg_isready() == STATE_REJECT:
@@ -301,15 +355,85 @@ class Postgresql(object):
 
         return self._cluster_info_state.get(name)
 
+    def replayed_location(self):
+        return self._cluster_info_state_get('replayed_location')
+
+    def received_location(self):
+        return self._cluster_info_state_get('received_location')
+
+    def slots(self):
+        return self._cluster_info_state_get('slots')
+
+    def primary_slot_name(self):
+        return self._cluster_info_state_get('slot_name')
+
+    def primary_conninfo(self):
+        return self._cluster_info_state_get('conninfo')
+
+    def received_timeline(self):
+        return self._cluster_info_state_get('received_tli')
+
     def is_leader(self):
-        return bool(self._cluster_info_state_get('timeline'))
+        try:
+            return bool(self._cluster_info_state_get('timeline'))
+        except PostgresConnectionException:
+            logger.warning('Failed to determine PostgreSQL state from the connection, falling back to cached role')
+            return bool(self.is_running() and self.role == 'master')
+
+    def replay_paused(self):
+        return self._cluster_info_state_get('replay_paused')
+
+    def resume_wal_replay(self):
+        self._query('SELECT pg_catalog.pg_{0}_replay_resume()'.format(self.wal_name))
+
+    def handle_parameter_change(self):
+        if self.major_version >= 140000 and self.replay_paused():
+            logger.info('Resuming paused WAL replay for PostgreSQL 14+')
+            self.resume_wal_replay()
 
     def pg_control_timeline(self):
         try:
+
             return int(self.controldata().get("Latest checkpoint's TimeLineID"))
         except (TypeError, ValueError):
             logger.exception('Failed to parse timeline from pg_controldata output')
 
+    def parse_wal_record(self, timeline, lsn):
+        out, err = self.waldump(timeline, lsn, 1)
+        if out and not err:
+            match = re.match(r'^rmgr:\s+(.+?)\s+len \(rec/tot\):\s+\d+/\s+\d+, tx:\s+\d+, '
+                             r'lsn: ([0-9A-Fa-f]+/[0-9A-Fa-f]+), prev ([0-9A-Fa-f]+/[0-9A-Fa-f]+), '
+                             r'.*?desc: (.+)', out.decode('utf-8'))
+            if match:
+                return match.groups()
+        return None, None, None, None
+
+    def latest_checkpoint_location(self):
+        """Returns checkpoint location for the cleanly shut down primary.
+           But, if we know that the checkpoint was written to the new WAL
+           due to the archive_mode=on, we will return the LSN of prev wal record (SWITCH)."""
+
+        data = self.controldata()
+        timeline = data.get("Latest checkpoint's TimeLineID")
+        lsn = checkpoint_lsn = data.get('Latest checkpoint location')
+        if data.get('Database cluster state') == 'shut down' and lsn and timeline:
+            try:
+                checkpoint_lsn = parse_lsn(checkpoint_lsn)
+                rm_name, lsn, prev, desc = self.parse_wal_record(timeline, lsn)
+                desc = desc.strip().lower()
+                if rm_name == 'XLOG' and parse_lsn(lsn) == checkpoint_lsn and prev and\
+                        desc.startswith('checkpoint') and desc.endswith('shutdown'):
+                    _, lsn, _, desc = self.parse_wal_record(timeline, prev)
+                    prev = parse_lsn(prev)
+                    # If the cluster is shutdown with archive_mode=on, WAL is switched before writing the checkpoint.
+                    # In this case we want to take the LSN of previous record (switch) as the last known WAL location.
+                    if parse_lsn(lsn) == prev and desc.strip() in ('xlog switch', 'SWITCH'):
+                        return str(prev)
+            except Exception as e:
+                logger.error('Exception when parsing WAL pg_%sdump output: %r', self.wal_name, e)
+            if isinstance(checkpoint_lsn, six.integer_types):
+                return str(checkpoint_lsn)
+
     def is_running(self):
         """Returns PostmasterProcess if one is running on the data directory or None. If most recently seen process
         is running updates the cached process based on pid file."""
@@ -318,7 +442,7 @@ class Postgresql(object):
                 return self._postmaster_proc
             self._postmaster_proc = None
 
-        # we noticed that postgres was restarted, force syncing of replication
+        # we noticed that postgres was restarted, force syncing of replication slots and check of logical slots
         self.slots_handler.schedule()
 
         self._postmaster_proc = PostmasterProcess.from_pidfile(self._data_dir)
@@ -415,6 +539,8 @@ class Postgresql(object):
         self._pending_restart = False
 
         try:
+            if not self._major_version:
+                self.configure_server_parameters()
             configuration = self.config.effective_configuration
         except Exception:
             return None
@@ -426,7 +552,7 @@ class Postgresql(object):
         self.config.replace_pg_ident()
 
         options = ['--{0}={1}'.format(p, configuration[p]) for p in self.config.CMDLINE_OPTIONS
-                   if p in configuration and p != 'wal_keep_segments']
+                   if p in configuration and p not in ('wal_keep_segments', 'wal_keep_size')]
 
         if self.cancellable.is_cancelled:
             return False
@@ -477,12 +603,13 @@ class Postgresql(object):
                     cur.execute('SELECT pg_catalog.pg_is_in_recovery()')
                     if cur.fetchone()[0]:
                         return 'is_in_recovery=true'
-                return cur.execute('CHECKPOINT')
-        except psycopg2.Error:
+                cur.execute('CHECKPOINT')
+        except psycopg.Error:
             logger.exception('Exception during CHECKPOINT')
             return 'not accessible or not healty'
 
-    def stop(self, mode='fast', block_callbacks=False, checkpoint=None, on_safepoint=None, stop_timeout=None):
+    def stop(self, mode='fast', block_callbacks=False, checkpoint=None,
+             on_safepoint=None, on_shutdown=None, stop_timeout=None):
         """Stop PostgreSQL
 
         Supports a callback when a safepoint is reached. A safepoint is when no user backend can return a successful
@@ -490,11 +617,12 @@ class Postgresql(object):
         could be added.
 
         :param on_safepoint: This callback is called when no user backends are running.
+        :param on_shutdown: is called when pg_controldata starts reporting `Database cluster state: shut down`
         """
         if checkpoint is None:
             checkpoint = False if mode == 'immediate' else True
 
-        success, pg_signaled = self._do_stop(mode, block_callbacks, checkpoint, on_safepoint, stop_timeout)
+        success, pg_signaled = self._do_stop(mode, block_callbacks, checkpoint, on_safepoint, on_shutdown, stop_timeout)
         if success:
             # block_callbacks is used during restart to avoid
             # running start/stop callbacks in addition to restart ones
@@ -507,7 +635,7 @@ class Postgresql(object):
             self.set_state('stop failed')
         return success
 
-    def _do_stop(self, mode, block_callbacks, checkpoint, on_safepoint, stop_timeout):
+    def _do_stop(self, mode, block_callbacks, checkpoint, on_safepoint, on_shutdown, stop_timeout):
         postmaster = self.is_running()
         if not postmaster:
             if on_safepoint:
@@ -534,6 +662,22 @@ class Postgresql(object):
             postmaster.wait_for_user_backends_to_close()
             on_safepoint()
 
+        if on_shutdown and mode in ('fast', 'smart'):
+            i = 0
+            # Wait for pg_controldata `Database cluster state:` to change to "shut down"
+            while postmaster.is_running():
+                data = self.controldata()
+                if data.get('Database cluster state', '') == 'shut down':
+                    on_shutdown(int(self.latest_checkpoint_location()))
+                    break
+                elif data.get('Database cluster state', '').startswith('shut down'):  # shut down in recovery
+                    break
+                elif stop_timeout and i >= stop_timeout:
+                    stop_timeout = 0
+                    break
+                time.sleep(STOP_POLLING_INTERVAL)
+                i += STOP_POLLING_INTERVAL
+
         try:
             postmaster.wait(timeout=stop_timeout)
         except TimeoutExpired:
@@ -568,12 +712,12 @@ class Postgresql(object):
                 while postmaster.is_running():  # Need a timeout here?
                     cur.execute("SELECT 1")
                     time.sleep(STOP_POLLING_INTERVAL)
-        except psycopg2.Error:
+        except psycopg.Error:
             pass
 
-    def reload(self):
+    def reload(self, block_callbacks=False):
         ret = self.pg_ctl('reload')
-        if ret:
+        if ret and not block_callbacks:
             self.call_nowait(ACTION_ON_RELOAD)
         return ret
 
@@ -653,9 +797,17 @@ class Postgresql(object):
             return False
         return True
 
+    def get_guc_value(self, name):
+        cmd = [self.pgcommand('postgres'), '-D', self._data_dir, '-C', name]
+        try:
+            data = subprocess.check_output(cmd)
+            if data:
+                return data.decode('utf-8').strip()
+        except Exception as e:
+            logger.error('Failed to execute %s: %r', cmd, e)
+
     def controldata(self):
         """ return the contents of pg_controldata, or non-True value if pg_controldata call failed """
-        result = {}
         # Don't try to call pg_controldata during backup restore
         if self._version_file_exists() and self.state != 'creating replica':
             try:
@@ -663,34 +815,42 @@ class Postgresql(object):
                 env.update(LANG='C', LC_ALL='C')
                 data = subprocess.check_output([self.pgcommand('pg_controldata'), self._data_dir], env=env)
                 if data:
-                    data = data.decode('utf-8').splitlines()
+                    data = filter(lambda e: ':' in e, data.decode('utf-8').splitlines())
                     # pg_controldata output depends on major version. Some of parameters are prefixed by 'Current '
-                    result = {l.split(':')[0].replace('Current ', '', 1): l.split(':', 1)[1].strip() for l in data
-                              if l and ':' in l}
+                    return {k.replace('Current ', '', 1): v.strip() for k, v in map(lambda e: e.split(':', 1), data)}
             except subprocess.CalledProcessError:
                 logger.exception("Error when calling pg_controldata")
-        return result
+        return {}
+
+    def waldump(self, timeline, lsn, limit):
+        cmd = self.pgcommand('pg_{0}dump'.format(self.wal_name))
+        env = os.environ.copy()
+        env.update(LANG='C', LC_ALL='C', PGDATA=self._data_dir)
+        try:
+            waldump = subprocess.Popen([cmd, '-t', str(timeline), '-s', str(lsn), '-n', str(limit)],
+                                       stdout=subprocess.PIPE, stderr=subprocess.PIPE, env=env)
+            out, err = waldump.communicate()
+            waldump.wait()
+            return out, err
+        except Exception as e:
+            logger.error('Failed to execute `%s -t %s -s %s -n %s`: %r', cmd, timeline, lsn, limit, e)
+            return None, None
 
     @contextmanager
-    def get_replication_connection_cursor(self, host='localhost', port=5432, **kwargs):
+    def get_replication_connection_cursor(self, host=None, port=5432, **kwargs):
         conn_kwargs = self.config.replication.copy()
         conn_kwargs.update(host=host, port=int(port) if port else None, user=conn_kwargs.pop('username'),
                            connect_timeout=3, replication=1, options='-c statement_timeout=2000')
         with get_connection_cursor(**conn_kwargs) as cur:
             yield cur
 
-    def get_local_timeline_lsn_from_replication_connection(self):
-        timeline = lsn = None
+    def get_replica_timeline(self):
         try:
             with self.get_replication_connection_cursor(**self.config.local_replication_address) as cur:
                 cur.execute('IDENTIFY_SYSTEM')
-                timeline, lsn = cur.fetchone()[1:3]
+                return cur.fetchone()[1]
         except Exception:
             logger.exception('Can not fetch local timeline and lsn from replication connection')
-        return timeline, lsn
-
-    def get_replica_timeline(self):
-        return self.get_local_timeline_lsn_from_replication_connection()[0]
 
     def replica_cached_timeline(self, master_timeline):
         if not self._cached_replica_timeline or not master_timeline or self._cached_replica_timeline != master_timeline:
@@ -701,19 +861,20 @@ class Postgresql(object):
         return self._cluster_info_state_get('timeline')
 
     def get_history(self, timeline):
-        history_path = 'pg_{0}/{1:08X}.history'.format(self.wal_name, timeline)
-        try:
-            cursor = self._connection.cursor()
-            cursor.execute('SELECT isdir, modification FROM pg_catalog.pg_stat_file(%s)', (history_path,))
-            isdir, modification = cursor.fetchone()
-            if not isdir:
-                cursor.execute('SELECT pg_catalog.pg_read_file(%s)', (history_path,))
-                history = list(parse_history(cursor.fetchone()[0]))
+        history_path = os.path.join(self.wal_dir, '{0:08X}.history'.format(timeline))
+        history_mtime = mtime(history_path)
+        if history_mtime:
+            try:
+                with open(history_path, 'r') as f:
+                    history = f.read()
+                history = list(parse_history(history))
                 if history[-1][0] == timeline - 1:
-                    history[-1].append(modification.isoformat())
+                    history_mtime = datetime.fromtimestamp(history_mtime).replace(tzinfo=tz.tzlocal())
+                    history[-1].append(history_mtime.isoformat())
+                    history[-1].append(self.name)
                 return history
-        except Exception:
-            logger.exception('Failed to read and parse %s', (history_path,))
+            except Exception:
+                logger.exception('Failed to read and parse %s', (history_path,))
 
     def follow(self, member, role='replica', timeout=None, do_reload=False):
         recovery_params = self.config.build_recovery_params(member)
@@ -728,19 +889,22 @@ class Postgresql(object):
         if change_role:
             self.__cb_pending = ACTION_NOOP
 
+        ret = True
         if self.is_running():
             if do_reload:
                 self.config.write_postgresql_conf()
-                self.reload()
+                ret = self.reload(block_callbacks=change_role)
+                if ret and change_role:
+                    self.set_role(role)
             else:
-                self.restart(block_callbacks=change_role, role=role)
+                ret = self.restart(block_callbacks=change_role, role=role)
         else:
-            self.start(timeout=timeout, block_callbacks=change_role, role=role)
+            ret = self.start(timeout=timeout, block_callbacks=change_role, role=role) or None
 
         if change_role:
             # TODO: postpone this until start completes, or maybe do even earlier
             self.call_nowait(ACTION_ON_ROLE_CHANGE)
-        return True
+        return ret
 
     def _wait_promote(self, wait_seconds):
         for _ in polling_loop(wait_seconds):
@@ -748,54 +912,136 @@ class Postgresql(object):
             if data.get('Database cluster state') == 'in production':
                 return True
 
-    def promote(self, wait_seconds, on_success=None, access_is_restricted=False):
+    def _pre_promote(self):
+        """
+        Runs a fencing script after the leader lock is acquired but before the replica is promoted.
+        If the script exits with a non-zero code, promotion does not happen and the leader key is removed from DCS.
+        """
+
+        cmd = self.config.get('pre_promote')
+        if not cmd:
+            return True
+
+        ret = self.cancellable.call(shlex.split(cmd))
+        if ret is not None:
+            logger.info('pre_promote script `%s` exited with %s', cmd, ret)
+        return ret == 0
+
+    def promote(self, wait_seconds, task, on_success=None):
         if self.role == 'master':
             return True
+
+        ret = self._pre_promote()
+        with task:
+            if task.is_cancelled:
+                return False
+            task.complete(ret)
+
+        if ret is False:
+            return False
+
+        if self.cancellable.is_cancelled:
+            logger.info("PostgreSQL promote cancelled.")
+            return False
+
+        self.slots_handler.on_promote()
+
         ret = self.pg_ctl('promote', '-W')
         if ret:
             self.set_role('master')
             if on_success is not None:
                 on_success()
-            if not access_is_restricted:
-                self.call_nowait(ACTION_ON_ROLE_CHANGE)
+            self.call_nowait(ACTION_ON_ROLE_CHANGE)
             ret = self._wait_promote(wait_seconds)
         return ret
 
+    @staticmethod
+    def _wal_position(is_leader, wal_position, received_location, replayed_location):
+        return wal_position if is_leader else max(received_location or 0, replayed_location or 0)
+
     def timeline_wal_position(self):
         # This method could be called from different threads (simultaneously with some other `_query` calls).
         # If it is called not from main thread we will create a new cursor to execute statement.
         if current_thread().ident == self.__thread_ident:
-            return (self._cluster_info_state_get('timeline'),
-                    self._cluster_info_state_get('wal_position'),
-                    self._cluster_info_state_get('pg_control_timeline'))
+            timeline = self._cluster_info_state_get('timeline')
+            wal_position = self._cluster_info_state_get('wal_position')
+            replayed_location = self.replayed_location()
+            received_location = self.received_location()
+            pg_control_timeline = self._cluster_info_state_get('pg_control_timeline')
+        else:
+            with self.connection().cursor() as cursor:
+                cursor.execute(self.cluster_info_query)
+                (timeline, wal_position, replayed_location,
+                 received_location, _, pg_control_timeline) = cursor.fetchone()[:6]
 
-        with self.connection().cursor() as cursor:
-            cursor.execute(self.cluster_info_query)
-            return cursor.fetchone()[:3]
+        wal_position = self._wal_position(timeline, wal_position, received_location, replayed_location)
+        return (timeline, wal_position, pg_control_timeline)
 
     def postmaster_start_time(self):
         try:
-            query = "SELECT pg_catalog.to_char(pg_catalog.pg_postmaster_start_time(), 'YYYY-MM-DD HH24:MI:SS.MS TZ')"
+            query = "SELECT " + self.POSTMASTER_START_TIME
             if current_thread().ident == self.__thread_ident:
-                return self.query(query).fetchone()[0]
+                return self.query(query).fetchone()[0].isoformat(sep=' ')
             with self.connection().cursor() as cursor:
                 cursor.execute(query)
-                return cursor.fetchone()[0]
-        except psycopg2.Error:
+                return cursor.fetchone()[0].isoformat(sep=' ')
+        except psycopg.Error:
             return None
 
     def last_operation(self):
-        return str(self._cluster_info_state_get('wal_position'))
+        return self._wal_position(self.is_leader(), self._cluster_info_state_get('wal_position'),
+                                  self.received_location(), self.replayed_location())
 
     def configure_server_parameters(self):
         self._major_version = self.get_major_version()
         self.config.setup_server_parameters()
         return True
 
+    def pg_wal_realpath(self):
+        """Returns a dict containing the symlink (key) and target (value) for the wal directory"""
+        links = {}
+        for pg_wal_dir in ('pg_xlog', 'pg_wal'):
+            pg_wal_path = os.path.join(self._data_dir, pg_wal_dir)
+            if os.path.exists(pg_wal_path) and os.path.islink(pg_wal_path):
+                pg_wal_realpath = os.path.realpath(pg_wal_path)
+                links[pg_wal_path] = pg_wal_realpath
+        return links
+
+    def pg_tblspc_realpaths(self):
+        """Returns a dict containing the symlink (key) and target (values) for the tablespaces"""
+        links = {}
+        pg_tblsp_dir = os.path.join(self._data_dir, 'pg_tblspc')
+        if os.path.exists(pg_tblsp_dir):
+            for tsdn in os.listdir(pg_tblsp_dir):
+                pg_tsp_path = os.path.join(pg_tblsp_dir, tsdn)
+                if parse_int(tsdn) and os.path.islink(pg_tsp_path):
+                    pg_tsp_rpath = os.path.realpath(pg_tsp_path)
+                    links[pg_tsp_path] = pg_tsp_rpath
+        return links
+
     def move_data_directory(self):
         if os.path.isdir(self._data_dir) and not self.is_running():
             try:
-                new_name = '{0}_{1}'.format(self._data_dir, time.strftime('%Y-%m-%d-%H-%M-%S'))
+                postfix = time.strftime('%Y-%m-%d-%H-%M-%S')
+
+                # let's see if the wal directory is a symlink, in this case we
+                # should move the target
+                for (source, pg_wal_realpath) in self.pg_wal_realpath().items():
+                    logger.info('renaming WAL directory and updating symlink: %s', pg_wal_realpath)
+                    new_name = '{0}_{1}'.format(pg_wal_realpath, postfix)
+                    os.rename(pg_wal_realpath, new_name)
+                    os.unlink(source)
+                    os.symlink(new_name, source)
+
+                # Move user defined tablespace directory
+                for (source, pg_tsp_rpath) in self.pg_tblspc_realpaths().items():
+                    logger.info('renaming user defined tablespace directory and updating symlink: %s', pg_tsp_rpath)
+                    new_name = '{0}_{1}'.format(pg_tsp_rpath, postfix)
+                    os.rename(pg_tsp_rpath, new_name)
+                    os.unlink(source)
+                    os.symlink(new_name, source)
+
+                new_name = '{0}_{1}'.format(self._data_dir, postfix)
                 logger.info('renaming data directory to %s', new_name)
                 os.rename(self._data_dir, new_name)
             except OSError:
@@ -813,114 +1059,82 @@ class Postgresql(object):
                 os.remove(self._data_dir)
             elif os.path.isdir(self._data_dir):
 
-                # let's see if pg_xlog|pg_wal is a symlink, in this case we
+                # let's see if wal directory is a symlink, in this case we
                 # should clean the target
-                for pg_wal_dir in ('pg_xlog', 'pg_wal'):
-                    pg_wal_path = os.path.join(self._data_dir, pg_wal_dir)
-                    if os.path.exists(pg_wal_path) and os.path.islink(pg_wal_path):
-                        pg_wal_realpath = os.path.realpath(pg_wal_path)
-                        logger.info('Removing WAL directory: %s', pg_wal_realpath)
-                        shutil.rmtree(pg_wal_realpath)
-                # Remove user defined tablespace directory
-                pg_tblsp_dir = os.path.join(self._data_dir, 'pg_tblspc')
-                if os.path.exists(pg_tblsp_dir):
-                    for tsdn in os.listdir(pg_tblsp_dir):
-                        pg_tsp_path = os.path.join(pg_tblsp_dir, tsdn)
-                        if parse_int(tsdn) and os.path.islink(pg_tsp_path):
-                            pg_tsp_rpath = os.path.realpath(pg_tsp_path)
-                            logger.info('Removing user defined tablespace directory: %s', pg_tsp_rpath)
-                            shutil.rmtree(pg_tsp_rpath, ignore_errors=True)
+                for pg_wal_realpath in self.pg_wal_realpath().values():
+                    logger.info('Removing WAL directory: %s', pg_wal_realpath)
+                    shutil.rmtree(pg_wal_realpath)
+
+                # Remove user defined tablespace directories
+                for pg_tsp_rpath in self.pg_tblspc_realpaths().values():
+                    logger.info('Removing user defined tablespace directory: %s', pg_tsp_rpath)
+                    shutil.rmtree(pg_tsp_rpath, ignore_errors=True)
 
                 shutil.rmtree(self._data_dir)
         except (IOError, OSError):
             logger.exception('Could not remove data directory %s', self._data_dir)
             self.move_data_directory()
 
-    def pick_synchronous_standby(self, cluster):
+    def _get_synchronous_commit_param(self):
+        return self.query("SHOW synchronous_commit").fetchone()[0]
+
+    def pick_synchronous_standby(self, cluster, sync_node_count=1, sync_node_maxlag=-1):
         """Finds the best candidate to be the synchronous standby.
 
         Current synchronous standby is always preferred, unless it has disconnected or does not want to be a
         synchronous standby any longer.
+        Parameter sync_node_maxlag(maximum_lag_on_syncnode) would help swapping unhealthy sync replica in case
+        if it stops responding (or hung). Please set the value high enough so it won't unncessarily swap sync
+        standbys during high loads. Any less or equal of 0 value keep the behavior backward compatible and
+        will not swap. Please note that it will not also swap sync standbys in case where all replicas are hung.
 
-        :returns tuple of candidate name or None, and bool showing if the member is the active synchronous standby.
+        :returns tuple of candidates list and synchronous standby list.
         """
-        current = cluster.sync.sync_standby
-        current = current.lower() if current else current
+        if self._major_version < 90600:
+            sync_node_count = 1
         members = {m.name.lower(): m for m in cluster.members}
         candidates = []
-        # Pick candidates based on who has flushed WAL farthest.
-        # TODO: for synchronous_commit = remote_write we actually want to order on write_location
-        for app_name, state, sync_state in self.query(
-                "SELECT pg_catalog.lower(application_name), state, sync_state"
+        sync_nodes = []
+        replica_list = []
+        # Pick candidates based on who has higher replay/remote_write/flush lsn.
+        sync_commit_par = self._get_synchronous_commit_param()
+        sort_col = {'remote_apply': 'replay', 'remote_write': 'write'}.get(sync_commit_par, 'flush')
+        # pg_stat_replication.sync_state has 4 possible states - async, potential, quorum, sync.
+        # Sort clause "ORDER BY sync_state DESC" is to get the result in required order and to keep
+        # the result consistent in case if a synchronous standby member is slowed down OR async node
+        # receiving changes faster than the sync member (very rare but possible). Such cases would
+        # trigger sync standby member swapping frequently and the sort on sync_state desc should
+        # help in keeping the query result consistent.
+        for app_name, sync_state, replica_lsn in self.query(
+                "SELECT pg_catalog.lower(application_name), sync_state, pg_{2}_{1}_diff({0}_{1}, '0/0')::bigint"
                 " FROM pg_catalog.pg_stat_replication"
-                " ORDER BY flush_{0} DESC".format(self.lsn_name)):
+                " WHERE state = 'streaming' AND {0}_{1} IS NOT NULL"
+                " ORDER BY sync_state DESC, {0}_{1} DESC".format(sort_col, self.lsn_name, self.wal_name)):
             member = members.get(app_name)
-            if state != 'streaming' or not member or member.tags.get('nosync', False):
-                continue
-            if sync_state == 'sync':
-                return member.name, True
-            if sync_state == 'potential' and app_name == current:
-                # Prefer current even if not the best one any more to avoid indecisivness and spurious swaps.
-                return cluster.sync.sync_standby, False
-            if sync_state in ('async', 'potential'):
-                candidates.append(member.name)
+            if member and not member.tags.get('nosync', False):
+                replica_list.append((member.name, sync_state, replica_lsn, bool(member.nofailover)))
 
-        if candidates:
-            return candidates[0], False
-        return None, False
+        max_lsn = max(replica_list, key=lambda x: x[2])[2] if len(replica_list) > 1 else int(str(self.last_operation()))
 
-    def read_postmaster_opts(self):
-        """returns the list of option names/values from postgres.opts, Empty dict if read failed or no file"""
-        result = {}
-        try:
-            with open(os.path.join(self._data_dir, 'postmaster.opts')) as f:
-                data = f.read()
-                for opt in data.split('" "'):
-                    if '=' in opt and opt.startswith('--'):
-                        name, val = opt.split('=', 1)
-                        result[name.strip('-')] = val.rstrip('"\n')
-        except IOError:
-            logger.exception('Error when reading postmaster.opts')
-        return result
+        # Prefer members without nofailover tag. We are relying on the fact that sorts are guaranteed to be stable.
+        for app_name, sync_state, replica_lsn, _ in sorted(replica_list, key=lambda x: x[3]):
+            if sync_node_maxlag <= 0 or max_lsn - replica_lsn <= sync_node_maxlag:
+                candidates.append(app_name)
+                if sync_state == 'sync':
+                    sync_nodes.append(app_name)
+            if len(candidates) >= sync_node_count:
+                break
 
-    def single_user_mode(self, command=None, options=None):
-        """run a given command in a single-user mode. If the command is empty - then just start and stop"""
-        cmd = [self.pgcommand('postgres'), '--single', '-D', self._data_dir]
-        for opt, val in sorted((options or {}).items()):
-            cmd.extend(['-c', '{0}={1}'.format(opt, val)])
-        # need a database name to connect
-        cmd.append(self._database)
-        return self.cancellable.call(cmd, communicate_input=command)
-
-    def cleanup_archive_status(self):
-        status_dir = os.path.join(self._data_dir, 'pg_' + self.wal_name, 'archive_status')
-        try:
-            for f in os.listdir(status_dir):
-                path = os.path.join(status_dir, f)
-                try:
-                    if os.path.islink(path):
-                        os.unlink(path)
-                    elif os.path.isfile(path):
-                        os.remove(path)
-                except OSError:
-                    logger.exception('Unable to remove %s', path)
-        except OSError:
-            logger.exception('Unable to list %s', status_dir)
-
-    def fix_cluster_state(self):
-        self.cleanup_archive_status()
-
-        # Start in a single user mode and stop to produce a clean shutdown
-        opts = self.read_postmaster_opts()
-        opts.update({'archive_mode': 'on', 'archive_command': 'false'})
-        self.config.remove_recovery_conf()
-        return self.single_user_mode(options=opts) == 0 or None
+        return candidates, sync_nodes
 
     def schedule_sanity_checks_after_pause(self):
         """
             After coming out of pause we have to:
-            1. sync replication slots, because it might happen that slots were removed
-            2. get new 'Database system identifier' to make sure that it wasn't changed
+            1. configure server parameters if necessary
+            2. sync replication slots, because it might happen that slots were removed
+            3. get new 'Database system identifier' to make sure that it wasn't changed
         """
+        if not self._major_version:
+            self.configure_server_parameters()
         self.slots_handler.schedule()
         self._sysid = None

patroni/postgresql/bootstrap.py

@@ -4,10 +4,12 @@ import shlex
 import tempfile
 import time
 
-from patroni.dcs import RemoteMember
-from patroni.utils import deep_compare
 from six import string_types
 
+from ..dcs import RemoteMember
+from ..psycopg import quote_ident, quote_literal
+from ..utils import deep_compare
+
 logger = logging.getLogger(__name__)
 
 
@@ -53,7 +55,7 @@ class Bootstrap(object):
                     error_handler('Error when parsing {0} option {1}: value should be string value'
                                   ' or a single key-value pair'.format(tool, opt))
         else:
-            error_handler('{0} options must be list ot dict'.format(tool))
+            error_handler('{0} options must be list or dict'.format(tool))
         return user_options
 
     def _initdb(self, config):
@@ -90,15 +92,16 @@ class Bootstrap(object):
         self._postgresql.configure_server_parameters()
 
         # make sure there is no trigger file or postgres will be automatically promoted
-        trigger_file = 'promote_trigger_file' if self._postgresql.major_version >= 120000 else 'trigger_file'
-        trigger_file = self._postgresql.config.get('recovery_conf', {}).get(trigger_file) or 'promote'
+        trigger_file = self._postgresql.config.triggerfile_good_name
+        trigger_file = (self._postgresql.config.get('recovery_conf') or {}).get(trigger_file) or 'promote'
         trigger_file = os.path.abspath(os.path.join(self._postgresql.data_dir, trigger_file))
         if os.path.exists(trigger_file):
             os.unlink(trigger_file)
 
     def _custom_bootstrap(self, config):
         self._postgresql.set_state('running custom bootstrap script')
-        params = ['--scope=' + self._postgresql.scope, '--datadir=' + self._postgresql.data_dir]
+        params = [] if config.get('no_params') else ['--scope=' + self._postgresql.scope,
+                                                     '--datadir=' + self._postgresql.data_dir]
         try:
             logger.info('Running custom bootstrap script: %s', config['command'])
             if self._postgresql.cancellable.call(shlex.split(config['command']) + params) != 0:
@@ -129,7 +132,8 @@ class Bootstrap(object):
                 # (pghost empty or the default socket directory) connections coming from the local machine.
                 r['host'] = 'localhost'  # set it to localhost to write into pgpass
 
-            env = self._postgresql.config.write_pgpass(r) if 'password' in r else None
+            env = self._postgresql.config.write_pgpass(r)
+            env['PGOPTIONS'] = '-c synchronous_commit=local'
 
             try:
                 ret = self._postgresql.cancellable.call(shlex.split(cmd) + [connstring], env=env)
@@ -295,26 +299,24 @@ class Bootstrap(object):
         if 'NOLOGIN' not in options and 'LOGIN' not in options:
             options.append('LOGIN')
 
-        params = [name]
         if password:
-            options.extend(['PASSWORD', '%s'])
-            params.extend([password, password])
+            options.extend(['PASSWORD', quote_literal(password)])
 
         sql = """DO $$
 BEGIN
     SET local synchronous_commit = 'local';
-    PERFORM * FROM pg_authid WHERE rolname = %s;
+    PERFORM * FROM pg_catalog.pg_authid WHERE rolname = {0};
     IF FOUND THEN
-        ALTER ROLE "{0}" WITH {1};
+        ALTER ROLE {1} WITH {2};
     ELSE
-        CREATE ROLE "{0}" WITH {1};
+        CREATE ROLE {1} WITH {2};
     END IF;
-END;$$""".format(name, ' '.join(options))
+END;$$""".format(quote_literal(name), quote_ident(name, self._postgresql.connection()), ' '.join(options))
         self._postgresql.query('SET log_statement TO none')
         self._postgresql.query('SET log_min_duration_statement TO -1')
         self._postgresql.query("SET log_min_error_statement TO 'log'")
         try:
-            self._postgresql.query(sql, *params)
+            self._postgresql.query(sql)
         finally:
             self._postgresql.query('RESET log_min_error_statement')
             self._postgresql.query('RESET log_min_duration_statement')
@@ -340,8 +342,8 @@ END;$$""".format(name, ' '.join(options))
                         sql = """DO $$
 BEGIN
     SET local synchronous_commit = 'local';
-    GRANT EXECUTE ON function pg_catalog.{0} TO "{1}";
-END;$$""".format(f, rewind['username'])
+    GRANT EXECUTE ON function pg_catalog.{0} TO {1};
+END;$$""".format(f, quote_ident(rewind['username'], self._postgresql.connection()))
                         postgresql.query(sql)
 
                 for name, value in (config.get('users') or {}).items():
@@ -354,7 +356,8 @@ END;$$""".format(f, rewind['username'])
                     self._running_custom_bootstrap = False
                     # If we don't have custom configuration for pg_hba.conf we need to restore original file
                     if not postgresql.config.get('pg_hba'):
-                        os.unlink(postgresql.config.pg_hba_conf)
+                        if os.path.exists(postgresql.config.pg_hba_conf):
+                            os.unlink(postgresql.config.pg_hba_conf)
                         postgresql.config.restore_configuration_files()
                     postgresql.config.write_postgresql_conf()
                     postgresql.config.replace_pg_ident()
@@ -362,7 +365,7 @@ END;$$""".format(f, rewind['username'])
                     # at this point there should be no recovery.conf
                     postgresql.config.remove_recovery_conf()
 
-                    if postgresql.config.hba_file and postgresql.config.hba_file != postgresql.config.pg_hba_conf:
+                    if postgresql.config.hba_file:
                         postgresql.restart()
                     else:
                         postgresql.config.replace_pg_hba()

patroni/postgresql/cancellable.py

@@ -1,11 +1,9 @@
 import logging
-import os
 import psutil
 import subprocess
 
 from patroni.exceptions import PostgresException
 from patroni.utils import polling_loop
-from six import string_types
 from threading import Lock
 
 logger = logging.getLogger(__name__)
@@ -13,6 +11,10 @@ logger = logging.getLogger(__name__)
 
 class CancellableExecutor(object):
 
+    """
+    There must be only one such process so that AsyncExecutor can easily cancel it.
+    """
+
     def __init__(self):
         self._process = None
         self._process_cmd = None
@@ -34,7 +36,7 @@ class CancellableExecutor(object):
         with self._lock:
             if self._process is not None and self._process.is_running() and not self._process_children:
                 try:
-                    self._process.suspend()  # Suspend the process before getting list of childrens
+                    self._process.suspend()  # Suspend the process before getting list of children
                 except psutil.Error as e:
                     logger.info('Failed to suspend the process: %s', e.msg)
 
@@ -75,16 +77,16 @@ class CancellableSubprocess(CancellableExecutor):
         for s in ('stdin', 'stdout', 'stderr'):
             kwargs.pop(s, None)
 
-        communicate_input = 'communicate_input' in kwargs
-        if communicate_input:
-            input_data = kwargs.pop('communicate_input', None)
-            if not isinstance(input_data, string_types):
-                input_data = ''
-            if input_data and input_data[-1] != '\n':
-                input_data += '\n'
+        communicate = kwargs.pop('communicate', None)
+        if isinstance(communicate, dict):
+            input_data = communicate.get('input')
+            if input_data:
+                if input_data[-1] != '\n':
+                    input_data += '\n'
+                input_data = input_data.encode('utf-8')
             kwargs['stdin'] = subprocess.PIPE
-            kwargs['stdout'] = open(os.devnull, 'w')
-            kwargs['stderr'] = subprocess.STDOUT
+            kwargs['stdout'] = subprocess.PIPE
+            kwargs['stderr'] = subprocess.PIPE
 
         try:
             with self._lock:
@@ -95,10 +97,8 @@ class CancellableSubprocess(CancellableExecutor):
                 started = self._start_process(*args, **kwargs)
 
             if started:
-                if communicate_input:
-                    if input_data:
-                        self._process.communicate(input_data)
-                    self._process.stdin.close()
+                if isinstance(communicate, dict):
+                    communicate['stdout'], communicate['stderr'] = self._process.communicate(input_data)
                 return self._process.wait()
         finally:
             with self._lock:
@@ -114,16 +114,20 @@ class CancellableSubprocess(CancellableExecutor):
         with self._lock:
             return self._is_cancelled
 
-    def cancel(self):
+    def cancel(self, kill=False):
         with self._lock:
             self._is_cancelled = True
             if self._process is None or not self._process.is_running():
                 return
+
+            logger.info('Terminating %s', self._process_cmd)
             self._process.terminate()
 
         for _ in polling_loop(10):
             with self._lock:
                 if self._process is None or not self._process.is_running():
                     return
+            if kill:
+                break
 
         self._kill_process()

patroni/postgresql/config.py

@@ -6,11 +6,13 @@ import socket
 import stat
 import time
 
-from patroni.exceptions import PatroniException
 from six.moves.urllib_parse import urlparse, parse_qsl, unquote
-from urllib3.response import HTTPHeaderDict
 
+from .validator import CaseInsensitiveDict, recovery_parameters,\
+        transform_postgresql_parameter_value, transform_recovery_parameter_value
 from ..dcs import slot_name_from_member_name, RemoteMember
+from ..exceptions import PatroniFatalException
+from ..psycopg import quote_ident as _quote_ident
 from ..utils import compare_values, parse_bool, parse_int, split_host_port, uri, \
         validate_directory, is_subpath
 
@@ -22,7 +24,7 @@ PARAMETER_RE = re.compile(r'([a-z_]+)\s*=\s*')
 
 def quote_ident(value):
     """Very simplified version of quote_ident"""
-    return value if SYNC_STANDBY_NAME_RE.match(value) else '"' + value + '"'
+    return value if SYNC_STANDBY_NAME_RE.match(value) else _quote_ident(value)
 
 
 def conninfo_uri_parse(dsn):
@@ -113,17 +115,17 @@ def parse_dsn(value):
     Very simple equivalent of `psycopg2.extensions.parse_dsn` introduced in 2.7.0.
     We are not using psycopg2 function in order to remain compatible with 2.5.4+.
     There is one minor difference though, this function removes `dbname` from the result
-    and sets the sslmode` to `prefer` if it is not present in the connection string.
-    This is necessary to simplify comparison of the old and the new values.
+    and sets the `sslmode`, 'gssencmode', and `channel_binding` to `prefer` if it is not present in
+    the connection string. This is necessary to simplify comparison of the old and the new values.
 
     >>> r = parse_dsn('postgresql://u%2Fse:pass@:%2f123,[%2Fhost2]/db%2Fsdf?application_name=mya%2Fpp&ssl=true')
     >>> r == {'application_name': 'mya/pp', 'host': ',/host2', 'sslmode': 'require',\
-              'password': 'pass', 'port': '/123', 'user': 'u/se'}
+              'password': 'pass', 'port': '/123', 'user': 'u/se', 'gssencmode': 'prefer', 'channel_binding': 'prefer'}
     True
     >>> r = parse_dsn(" host = 'host' dbname = db\\\\ name requiressl=1 ")
-    >>> r == {'host': 'host', 'sslmode': 'require'}
+    >>> r == {'host': 'host', 'sslmode': 'require', 'gssencmode': 'prefer', 'channel_binding': 'prefer'}
     True
-    >>> parse_dsn('requiressl = 0\\\\') == {'sslmode': 'prefer'}
+    >>> parse_dsn('requiressl = 0\\\\') == {'sslmode': 'prefer', 'gssencmode': 'prefer', 'channel_binding': 'prefer'}
     True
     >>> parse_dsn("host=a foo = '") is None
     True
@@ -147,6 +149,8 @@ def parse_dsn(value):
             ret.setdefault('sslmode', 'prefer')
         if 'dbname' in ret:
             del ret['dbname']
+        ret.setdefault('gssencmode', 'prefer')
+        ret.setdefault('channel_binding', 'prefer')
     return ret
 
 
@@ -252,21 +256,6 @@ class ConfigWriter(object):
         self.writeline("{0} = '{1}'".format(param, self.escape(value)))
 
 
-class CaseInsensitiveDict(HTTPHeaderDict):
-
-    def add(self, key, val):
-        self[key] = val
-
-    def __getitem__(self, key):
-        return self._container[key.lower()][1]
-
-    def __repr__(self):
-        return str(dict(self.items()))
-
-    def copy(self):
-        return CaseInsensitiveDict(self._container.values())
-
-
 class ConfigHandler(object):
 
     # List of parameters which must be always passed to postmaster as command line options
@@ -292,6 +281,7 @@ class ConfigHandler(object):
         'max_connections': (100, lambda v: int(v) >= 25, 90100),
         'max_wal_senders': (10, lambda v: int(v) >= 3, 90100),
         'wal_keep_segments': (8, lambda v: int(v) >= 1, 90100),
+        'wal_keep_size': ('128MB', lambda v: parse_int(v, 'MB') >= 16, 130000),
         'max_prepared_transactions': (0, lambda v: int(v) >= 0, 90100),
         'max_locks_per_transaction': (64, lambda v: int(v) >= 32, 90100),
         'track_commit_timestamp': ('off', lambda v: parse_bool(v) is not None, 90500),
@@ -300,24 +290,7 @@ class ConfigHandler(object):
         'wal_log_hints': ('on', lambda _: False, 90400)
     })
 
-    _RECOVERY_PARAMETERS = {
-        'archive_cleanup_command',
-        'restore_command',
-        'recovery_end_command',
-        'recovery_target',
-        'recovery_target_name',
-        'recovery_target_time',
-        'recovery_target_xid',
-        'recovery_target_lsn',
-        'recovery_target_inclusive',
-        'recovery_target_timeline',
-        'recovery_target_action',
-        'recovery_min_apply_delay',
-        'primary_conninfo',
-        'primary_slot_name',
-        'promote_trigger_file',
-        'trigger_file'
-    }
+    _RECOVERY_PARAMETERS = set(recovery_parameters.keys())
 
     def __init__(self, postgresql, config):
         self._postgresql = postgresql
@@ -337,8 +310,8 @@ class ConfigHandler(object):
         self._auto_conf_mtime = None
         self._pgpass = os.path.abspath(config.get('pgpass') or os.path.join(os.path.expanduser('~'), 'pgpass'))
         if os.path.exists(self._pgpass) and not os.path.isfile(self._pgpass):
-            raise PatroniException("'{}' exists and it's not a file, check your `postgresql.pgpass` configuration"
-                                   .format(self._pgpass))
+            raise PatroniFatalException("'{0}' exists and it's not a file, check your `postgresql.pgpass` configuration"
+                                        .format(self._pgpass))
         self._passfile = None
         self._passfile_mtime = None
         self._synchronous_standby_names = None
@@ -364,8 +337,9 @@ class ConfigHandler(object):
         if "stats_temp_directory" in self._server_parameters:
             self.try_to_create_dir(self._server_parameters["stats_temp_directory"],
                                    "'{}' is defined in stats_temp_directory, {}")
-        self.try_to_create_dir(os.path.dirname(self._pgpass),
-                               "'{}' is defined in `postgresql.pgpass`, {}")
+        if not self._krbsrvname:
+            self.try_to_create_dir(os.path.dirname(self._pgpass),
+                                   "'{}' is defined in `postgresql.pgpass`, {}")
 
     @property
     def _configuration_to_save(self):
@@ -374,13 +348,13 @@ class ConfigHandler(object):
             configuration.append(os.path.basename(self._postgresql_base_conf_name))
         if not self.hba_file:
             configuration.append('pg_hba.conf')
-        if not self._server_parameters.get('ident_file'):
+        if not self.ident_file:
             configuration.append('pg_ident.conf')
         return configuration
 
     def save_configuration_files(self, check_custom_bootstrap=False):
         """
-            copy postgresql.conf to postgresql.conf.backup to be able to retrive configuration files
+            copy postgresql.conf to postgresql.conf.backup to be able to retrieve configuration files
             - originally stored as symlinks, those are normally skipped by pg_basebackup
             - in case of WAL-E basebackup (see http://comments.gmane.org/gmane.comp.db.postgresql.wal-e/239)
         """
@@ -415,16 +389,22 @@ class ConfigHandler(object):
         if 'custom_conf' not in self._config and not os.path.exists(self._postgresql_base_conf):
             os.rename(self._postgresql_conf, self._postgresql_base_conf)
 
+        configuration = configuration or self._server_parameters.copy()
+        # Due to the permanent logical replication slots configured we have to enable hot_standby_feedback
+        if self._postgresql.enforce_hot_standby_feedback:
+            configuration['hot_standby_feedback'] = 'on'
+
         with ConfigWriter(self._postgresql_conf) as f:
             include = self._config.get('custom_conf') or self._postgresql_base_conf_name
             f.writeline("include '{0}'\n".format(ConfigWriter.escape(include)))
-            for name, value in sorted((configuration or self._server_parameters).items()):
-                if (not self._postgresql.bootstrap.running_custom_bootstrap or name != 'hba_file') \
-                        and name not in self._RECOVERY_PARAMETERS:
+            for name, value in sorted((configuration).items()):
+                value = transform_postgresql_parameter_value(self._postgresql.major_version, name, value)
+                if value is not None and\
+                        (name != 'hba_file' or not self._postgresql.bootstrap.running_custom_bootstrap):
                     f.write_param(name, value)
             # when we are doing custom bootstrap we assume that we don't know superuser password
             # and in order to be able to change it, we are opening trust access from a certain address
-            # therefore we need to make sure that hba_file is not overriden
+            # therefore we need to make sure that hba_file is not overridden
             # after changing superuser password we will "revert" all these "changes"
             if self._postgresql.bootstrap.running_custom_bootstrap or 'hba_file' not in self._server_parameters:
                 f.write_param('hba_file', self._pg_hba_conf)
@@ -481,7 +461,7 @@ class ConfigHandler(object):
         :returns: True if pg_ident.conf was rewritten.
         """
 
-        if not self._server_parameters.get('ident_file') and self._config.get('pg_ident'):
+        if not self.ident_file and self._config.get('pg_ident'):
             with ConfigWriter(self._pg_ident_conf) as f:
                 f.writelines(self._config['pg_ident'])
             return True
@@ -492,19 +472,25 @@ class ConfigHandler(object):
         ret = member.conn_kwargs(self.replication)
         ret['application_name'] = self._postgresql.name
         ret.setdefault('sslmode', 'prefer')
+        if self._postgresql.major_version >= 120000:
+            ret.setdefault('gssencmode', 'prefer')
+        if self._postgresql.major_version >= 130000:
+            ret.setdefault('channel_binding', 'prefer')
         if self._krbsrvname:
             ret['krbsrvname'] = self._krbsrvname
-        if 'database' in ret:
-            del ret['database']
+        if 'dbname' in ret:
+            del ret['dbname']
         return ret
 
     def format_dsn(self, params, include_dbname=False):
         # A list of keywords that can be found in a conninfo string. Follows what is acceptable by libpq
-        keywords = ('dbname', 'user', 'passfile' if params.get('passfile') else 'password', 'host', 'port', 'sslmode',
-                    'sslcompression', 'sslcert', 'sslkey', 'sslrootcert', 'sslcrl', 'application_name', 'krbsrvname')
+        keywords = ('dbname', 'user', 'passfile' if params.get('passfile') else 'password', 'host', 'port',
+                    'sslmode', 'sslcompression', 'sslcert', 'sslkey', 'sslpassword', 'sslrootcert', 'sslcrl',
+                    'sslcrldir', 'application_name', 'krbsrvname', 'gssencmode', 'channel_binding')
         if include_dbname:
             params = params.copy()
-            params['dbname'] = params.get('database') or self._postgresql.database
+            if 'dbname' not in params:
+                params['dbname'] = self._postgresql.database
             # we are abusing information about the necessity of dbname
             # dsn should contain passfile or password only if there is no dbname in it (it is used in recovery.conf)
             skip = {'passfile', 'password'}
@@ -518,6 +504,13 @@ class ConfigHandler(object):
                         if kw not in skip and params.get(kw) is not None)
 
     def _write_recovery_params(self, fd, recovery_params):
+        if self._postgresql.major_version >= 90500:
+            pause_at_recovery_target = parse_bool(recovery_params.pop('pause_at_recovery_target', None))
+            if pause_at_recovery_target is not None:
+                recovery_params.setdefault('recovery_target_action', 'pause' if pause_at_recovery_target else 'promote')
+        else:
+            if str(recovery_params.pop('recovery_target_action', None)).lower() == 'promote':
+                recovery_params.setdefault('pause_at_recovery_target', 'false')
         for name, value in sorted(recovery_params.items()):
             if name == 'primary_conninfo':
                 if 'password' in value and self._postgresql.major_version >= 100000:
@@ -525,6 +518,10 @@ class ConfigHandler(object):
                     value['passfile'] = self._passfile = self._pgpass
                     self._passfile_mtime = mtime(self._pgpass)
                 value = self.format_dsn(value)
+            else:
+                value = transform_recovery_parameter_value(self._postgresql.major_version, name, value)
+                if value is None:
+                    continue
             fd.write_param(name, value)
 
     def build_recovery_params(self, member):
@@ -559,7 +556,7 @@ class ConfigHandler(object):
         return os.path.exists(self._recovery_conf)
 
     @property
-    def _triggerfile_good_name(self):
+    def triggerfile_good_name(self):
         return 'trigger_file' if self._postgresql.major_version < 120000 else 'promote_trigger_file'
 
     @property
@@ -568,7 +565,8 @@ class ConfigHandler(object):
 
     @property
     def _recovery_parameters_to_compare(self):
-        skip_params = {'recovery_target_inclusive', 'recovery_target_action', self._triggerfile_wrong_name}
+        skip_params = {'pause_at_recovery_target', 'recovery_target_inclusive',
+                       'recovery_target_action', 'standby_mode', self._triggerfile_wrong_name}
         return self._RECOVERY_PARAMETERS - skip_params
 
     def _read_recovery_params(self):
@@ -645,6 +643,17 @@ class ConfigHandler(object):
         elif not primary_conninfo:
             return False
 
+        wal_receiver_primary_conninfo = self._postgresql.primary_conninfo()
+        if wal_receiver_primary_conninfo:
+            wal_receiver_primary_conninfo = parse_dsn(wal_receiver_primary_conninfo)
+            # when wal receiver is alive use primary_conninfo from pg_stat_wal_receiver for comparison
+            if wal_receiver_primary_conninfo:
+                primary_conninfo = wal_receiver_primary_conninfo
+                # There could be no password in the primary_conninfo or it is masked.
+                # Just copy the "desired" value in order to make comparison succeed.
+                if 'password' in wanted_primary_conninfo:
+                    primary_conninfo['password'] = wanted_primary_conninfo['password']
+
         if 'passfile' in primary_conninfo and 'password' not in primary_conninfo \
                 and 'password' in wanted_primary_conninfo:
             if self._check_passfile(primary_conninfo['passfile'], wanted_primary_conninfo):
@@ -688,7 +697,16 @@ class ConfigHandler(object):
             else:  # empty string, primary_conninfo is not in the config
                 primary_conninfo[0] = {}
 
-        required = {'restart': 0, 'reload': 0}
+        # when wal receiver is alive take primary_slot_name from pg_stat_wal_receiver
+        wal_receiver_primary_slot_name = self._postgresql.primary_slot_name()
+        if not wal_receiver_primary_slot_name and self._postgresql.primary_conninfo():
+            wal_receiver_primary_slot_name = ''
+        if wal_receiver_primary_slot_name is not None:
+            self._current_recovery_params['primary_slot_name'][0] = wal_receiver_primary_slot_name
+
+        # Increment the 'reload' to enforce write of postgresql.conf when joining the running postgres
+        required = {'restart': 0,
+                    'reload': int(not self._postgresql.cb_called and self._postgresql.major_version >= 120000)}
 
         def record_missmatch(mtype):
             required['restart' if mtype else 'reload'] += 1
@@ -704,6 +722,9 @@ class ConfigHandler(object):
             if param == 'recovery_min_apply_delay':
                 if not compare_values('integer', 'ms', value[0], wanted_recovery_params.get(param, 0)):
                     record_missmatch(value[1])
+            elif param == 'standby_mode':
+                if not compare_values('bool', None, value[0], wanted_recovery_params.get(param, 'on')):
+                    record_missmatch(value[1])
             elif param == 'primary_conninfo':
                 if not self._check_primary_conninfo(value[0], wanted_recovery_params.get('primary_conninfo', {})):
                     record_missmatch(value[1])
@@ -723,7 +744,7 @@ class ConfigHandler(object):
             def escape(value):
                 return re.sub(r'([:\\])', r'\\\1', str(value))
 
-            record = {n: escape(record.get(n, '*')) for n in ('host', 'port', 'user', 'password')}
+            record = {n: escape(record.get(n) or '*') for n in ('host', 'port', 'user', 'password')}
             return '{host}:{port}:*:{user}:{password}'.format(**record)
 
     def write_pgpass(self, record):
@@ -740,13 +761,13 @@ class ConfigHandler(object):
         return env
 
     def write_recovery_conf(self, recovery_params):
+        self._recovery_params = recovery_params
         if self._postgresql.major_version >= 120000:
             if parse_bool(recovery_params.pop('standby_mode', None)):
                 open(self._standby_signal, 'w').close()
             else:
                 self._remove_file_if_exists(self._standby_signal)
                 open(self._recovery_signal, 'w').close()
-            self._recovery_params = recovery_params
         else:
             with ConfigWriter(self._recovery_conf) as f:
                 os.chmod(self._recovery_conf, stat.S_IWRITE | stat.S_IREAD)
@@ -790,8 +811,8 @@ class ConfigHandler(object):
 
         if self.get('recovery_conf'):
             value = self._config['recovery_conf'].pop(self._triggerfile_wrong_name, None)
-            if self._triggerfile_good_name not in self._config['recovery_conf'] and value:
-                self._config['recovery_conf'][self._triggerfile_good_name] = value
+            if self.triggerfile_good_name not in self._config['recovery_conf'] and value:
+                self._config['recovery_conf'][self.triggerfile_good_name] = value
 
     def get_server_parameters(self, config):
         parameters = config['parameters'].copy()
@@ -805,8 +826,20 @@ class ConfigHandler(object):
                     parameters.pop('synchronous_standby_names', None)
             else:
                 parameters['synchronous_standby_names'] = self._synchronous_standby_names
-        if self._postgresql.major_version >= 90600 and parameters['wal_level'] == 'hot_standby':
-            parameters['wal_level'] = 'replica'
+
+        # Handle hot_standby <-> replica rename
+        if parameters.get('wal_level') == ('hot_standby' if self._postgresql.major_version >= 90600 else 'replica'):
+            parameters['wal_level'] = 'replica' if self._postgresql.major_version >= 90600 else 'hot_standby'
+
+        # Try to recalcualte wal_keep_segments <-> wal_keep_size assuming that typical wal_segment_size is 16MB.
+        # The real segment size could be estimated from pg_control, but we don't really care, because the only goal of
+        # this exercise is improving cross version compatibility and user must set the correct parameter in the config.
+        if self._postgresql.major_version >= 130000:
+            wal_keep_segments = parameters.pop('wal_keep_segments', self.CMDLINE_OPTIONS['wal_keep_segments'][0])
+            parameters.setdefault('wal_keep_size', str(int(wal_keep_segments) * 16) + 'MB')
+        elif self._postgresql.major_version:
+            wal_keep_size = parse_int(parameters.pop('wal_keep_size', self.CMDLINE_OPTIONS['wal_keep_size'][0]), 'MB')
+            parameters.setdefault('wal_keep_segments', int((wal_keep_size + 8) / 16))
         ret = CaseInsensitiveDict({k: v for k, v in parameters.items() if not self._postgresql.major_version or
                                    self._postgresql.major_version >= self.CMDLINE_OPTIONS.get(k, (0, 1, 90100))[2]})
         ret.update({k: os.path.join(self._config_dir, ret[k]) for k in ('hba_file', 'ident_file') if k in ret})
@@ -839,7 +872,7 @@ class ConfigHandler(object):
             ret['user'] = self._superuser['username']
             del ret['username']
         # ensure certain Patroni configurations are available
-        ret.update({'database': self._postgresql.database,
+        ret.update({'dbname': self._postgresql.database,
                     'fallback_application_name': 'Patroni',
                     'connect_timeout': 3,
                     'options': '-c statement_timeout=2000'})
@@ -848,25 +881,21 @@ class ConfigHandler(object):
     def resolve_connection_addresses(self):
         port = self._server_parameters['port']
         tcp_local_address = self._get_tcp_local_address()
-
-        local_address = {'port': port}
-        if self._config.get('use_unix_socket'):
-            unix_socket_directories = self._server_parameters.get('unix_socket_directories')
-            if unix_socket_directories is not None:
-                # fallback to tcp if unix_socket_directories is set, but there are no sutable values
-                local_address['host'] = self._get_unix_local_address(unix_socket_directories) or tcp_local_address
-
-            # if unix_socket_directories is not specified, but use_unix_socket is set to true - do our best
-            # to use default value, i.e. don't specify a host neither in connection url nor arguments
-        else:
-            local_address['host'] = tcp_local_address
-
-        self._local_address = local_address
-        self.local_replication_address = {'host': tcp_local_address, 'port': port}
-
         netloc = self._config.get('connect_address') or tcp_local_address + ':' + port
-        self._postgresql.connection_string = uri('postgres', netloc, self._postgresql.database)
 
+        unix_local_address = {'port': port}
+        unix_socket_directories = self._server_parameters.get('unix_socket_directories')
+        if unix_socket_directories is not None:
+            # fallback to tcp if unix_socket_directories is set, but there are no suitable values
+            unix_local_address['host'] = self._get_unix_local_address(unix_socket_directories) or tcp_local_address
+
+        tcp_local_address = {'host': tcp_local_address, 'port': port}
+
+        self._local_address = unix_local_address if self._config.get('use_unix_socket') else tcp_local_address
+        self.local_replication_address = unix_local_address\
+            if self._config.get('use_unix_socket_repl') else tcp_local_address
+
+        self._postgresql.connection_string = uri('postgres', netloc, self._postgresql.database)
         self._postgresql.set_connection_kwargs(self.local_connect_kwargs)
 
     def _get_pg_settings(self, names):
@@ -938,10 +967,12 @@ class ConfigHandler(object):
                         logger.warning('Removing invalid parameter `%s` from postgresql.parameters', param)
                         server_parameters.pop(param)
 
-            if not server_parameters.get('hba_file') and config.get('pg_hba'):
+            if (not server_parameters.get('hba_file') or server_parameters['hba_file'] == self._pg_hba_conf) \
+                    and config.get('pg_hba'):
                 hba_changed = self._config.get('pg_hba', []) != config['pg_hba']
 
-            if not server_parameters.get('ident_file') and config.get('pg_ident'):
+            if (not server_parameters.get('ident_file') or server_parameters['ident_file'] == self._pg_hba_conf) \
+                    and config.get('pg_ident'):
                 ident_changed = self._config.get('pg_ident', []) != config['pg_ident']
 
         self._config = config
@@ -972,24 +1003,29 @@ class ConfigHandler(object):
             if self._postgresql.major_version >= 90500:
                 time.sleep(1)
                 try:
-                    pending_restart = self._postgresql.query('SELECT COUNT(*) FROM pg_catalog.pg_settings'
-                                                             ' WHERE pending_restart').fetchone()[0] > 0
+                    pending_restart = self._postgresql.query(
+                        'SELECT COUNT(*) FROM pg_catalog.pg_settings WHERE pg_catalog.lower(name) != ALL(%s)'
+                        ' AND pending_restart', [n.lower() for n in self._RECOVERY_PARAMETERS]).fetchone()[0] > 0
                     self._postgresql.set_pending_restart(pending_restart)
                 except Exception as e:
                     logger.warning('Exception %r when running query', e)
         else:
             logger.info('No PostgreSQL configuration items changed, nothing to reload.')
 
-    def set_synchronous_standby(self, name):
+    def set_synchronous_standby(self, sync_members):
         """Sets a node to be synchronous standby and if changed does a reload for PostgreSQL."""
-        if name and name != '*':
-            name = quote_ident(name)
-        if name != self._synchronous_standby_names:
-            if name is None:
+        if sync_members and sync_members != ['*']:
+            sync_members = [quote_ident(x) for x in sync_members]
+        if self._postgresql.major_version >= 90600 and len(sync_members) > 1:
+            sync_param = '{0} ({1})'.format(len(sync_members), ','.join(sync_members))
+        else:
+            sync_param = next(iter(sync_members), None)
+        if sync_param != self._synchronous_standby_names:
+            if sync_param is None:
                 self._server_parameters.pop('synchronous_standby_names', None)
             else:
-                self._server_parameters['synchronous_standby_names'] = name
-            self._synchronous_standby_names = name
+                self._server_parameters['synchronous_standby_names'] = sync_param
+            self._synchronous_standby_names = sync_param
             if self._postgresql.state == 'running':
                 self.write_postgresql_conf()
                 self._postgresql.reload()
@@ -1033,6 +1069,14 @@ class ConfigHandler(object):
             if cvalue > value:
                 effective_configuration[name] = cvalue
                 self._postgresql.set_pending_restart(True)
+
+        # If we are using custom bootstrap with PITR it could fail when values
+        # like max_connections are increased, therefore we disable hot_standby.
+        if self._postgresql.bootstrap.running_custom_bootstrap and \
+                (self._postgresql.bootstrap.keep_existing_recovery_conf or self._recovery_conf):
+            effective_configuration['hot_standby'] = 'off'
+            self._postgresql.set_pending_restart(True)
+
         return effective_configuration
 
     @property
@@ -1048,9 +1092,15 @@ class ConfigHandler(object):
         return self._config['authentication'].get('rewind', self._superuser) \
                 if self._postgresql.major_version >= 110000 else self._superuser
 
+    @property
+    def ident_file(self):
+        ident_file = self._server_parameters.get('ident_file')
+        return None if ident_file == self._pg_ident_conf else ident_file
+
     @property
     def hba_file(self):
-        return self._server_parameters.get('hba_file')
+        hba_file = self._server_parameters.get('hba_file')
+        return None if hba_file == self._pg_hba_conf else hba_file
 
     @property
     def pg_hba_conf(self):

patroni/postgresql/connection.py

@@ -1,9 +1,10 @@
 import logging
-import psycopg2
 
 from contextlib import contextmanager
 from threading import Lock
 
+from .. import psycopg
+
 logger = logging.getLogger(__name__)
 
 
@@ -20,7 +21,7 @@ class Connection(object):
     def get(self):
         with self._lock:
             if not self._connection or self._connection.closed != 0:
-                self._connection = psycopg2.connect(**self._conn_kwargs)
+                self._connection = psycopg.connect(**self._conn_kwargs)
                 self._connection.autocommit = True
                 self.server_version = self._connection.server_version
         return self._connection
@@ -40,7 +41,8 @@ class Connection(object):
 
 @contextmanager
 def get_connection_cursor(**kwargs):
-    with psycopg2.connect(**kwargs) as conn:
-        conn.autocommit = True
-        with conn.cursor() as cur:
-            yield cur
+    conn = psycopg.connect(**kwargs)
+    conn.autocommit = True
+    with conn.cursor() as cur:
+        yield cur
+    conn.close()

patroni/postgresql/misc.py

@@ -37,7 +37,7 @@ def postgres_version_to_int(pg_version):
         raise PostgresException('Invalid PostgreSQL version format: X.Y or X.Y.Z is accepted: {0}'.format(pg_version))
 
     if len(components) == 2:
-        # new style verion numbers, i.e. 10.1 becomes 100001
+        # new style version numbers, i.e. 10.1 becomes 100001
         components.insert(1, 0)
 
     return int(''.join('{0:02d}'.format(c) for c in components))
@@ -68,3 +68,8 @@ def parse_history(data):
                 yield values
             except (IndexError, ValueError):
                 logger.exception('Exception when parsing timeline history line "%s"', values)
+
+
+def format_lsn(lsn, full=False):
+    template = '{0:X}/{1:08X}' if full else '{0:X}/{1:X}'
+    return template.format(lsn >> 32, lsn & 0xFFFFFFFF)

patroni/postgresql/postmaster.py

@@ -187,10 +187,10 @@ class PostmasterProcess(psutil.Process):
         user_backends_cmdlines = []
         for child in children:
             try:
-                cmdline = child.cmdline()[0]
-                if not aux_proc_re.match(cmdline):
+                cmdline = child.cmdline()
+                if cmdline and not aux_proc_re.match(cmdline[0]):
                     user_backends.append(child)
-                    user_backends_cmdlines.append(cmdline)
+                    user_backends_cmdlines.append(cmdline[0])
             except psutil.NoSuchProcess:
                 pass
         if user_backends:

patroni/postgresql/rewind.py

@@ -1,11 +1,13 @@
 import logging
 import os
+import shlex
+import six
 import subprocess
 
 from threading import Lock, Thread
 
 from .connection import get_connection_cursor
-from .misc import parse_history, parse_lsn
+from .misc import format_lsn, parse_history, parse_lsn
 from ..async_executor import CriticalTask
 from ..dcs import Leader
 
@@ -52,11 +54,10 @@ class Rewind(object):
         if self.can_rewind_or_reinitialize_allowed and self._state != REWIND_STATUS.NEED:
             self._state = REWIND_STATUS.CHECK
 
-    def check_leader_is_not_in_recovery(self, **kwargs):
-        if not kwargs.get('database'):
-            kwargs['database'] = self._postgresql.database
+    @staticmethod
+    def check_leader_is_not_in_recovery(conn_kwargs):
         try:
-            with get_connection_cursor(connect_timeout=3, options='-c statement_timeout=2000', **kwargs) as cur:
+            with get_connection_cursor(connect_timeout=3, options='-c statement_timeout=2000', **conn_kwargs) as cur:
                 cur.execute('SELECT pg_catalog.pg_is_in_recovery()')
                 if not cur.fetchone()[0]:
                     return True
@@ -64,40 +65,107 @@ class Rewind(object):
         except Exception:
             return logger.exception('Exception when working with leader')
 
+    def _get_checkpoint_end(self, timeline, lsn):
+        """The checkpoint record size in WAL depends on postgres major version and platform (memory alignment).
+        Hence, the only reliable way to figure out where it ends, read the record from file with the help of pg_waldump
+        and parse the output. We are trying to read two records, and expect that it will fail to read the second one:
+        `pg_waldump: fatal: error in WAL record at 0/182E220: invalid record length at 0/182E298: wanted 24, got 0`
+        The error message contains information about LSN of the next record, which is exactly where checkpoint ends."""
+
+        lsn8 = format_lsn(lsn, True)
+        lsn = format_lsn(lsn)
+        out, err = self._postgresql.waldump(timeline, lsn, 2)
+        if out is not None and err is not None:
+            out = out.decode('utf-8').rstrip().split('\n')
+            err = err.decode('utf-8').rstrip().split('\n')
+            pattern = 'error in WAL record at {0}: invalid record length at '.format(lsn)
+
+            if len(out) == 1 and len(err) == 1 and ', lsn: {0}, prev '.format(lsn8) in out[0] and pattern in err[0]:
+                i = err[0].find(pattern) + len(pattern)
+                j = err[0].find(": wanted ", i)
+                if j > -1:
+                    try:
+                        return parse_lsn(err[0][i:j])
+                    except Exception as e:
+                        logger.error('Failed to parse lsn %s: %r', err[0][i:j], e)
+            logger.error('Failed to parse pg_%sdump output', self._postgresql.wal_name)
+            logger.error(' stdout=%s', '\n'.join(out))
+            logger.error(' stderr=%s', '\n'.join(err))
+
+        return 0
+
     def _get_local_timeline_lsn_from_controldata(self):
-        timeline = lsn = None
+        in_recovery = timeline = lsn = None
         data = self._postgresql.controldata()
         try:
             if data.get('Database cluster state') == 'shut down in recovery':
+                in_recovery = True
                 lsn = data.get('Minimum recovery ending location')
                 timeline = int(data.get("Min recovery ending loc's timeline"))
                 if lsn == '0/0' or timeline == 0:  # it was a master when it crashed
                     data['Database cluster state'] = 'shut down'
             if data.get('Database cluster state') == 'shut down':
+                in_recovery = False
                 lsn = data.get('Latest checkpoint location')
                 timeline = int(data.get("Latest checkpoint's TimeLineID"))
         except (TypeError, ValueError):
             logger.exception('Failed to get local timeline and lsn from pg_controldata output')
-        return timeline, lsn
+
+        if lsn is not None:
+            try:
+                lsn = parse_lsn(lsn)
+            except (IndexError, ValueError) as e:
+                logger.error('Exception when parsing lsn %s: %r', lsn, e)
+                lsn = None
+
+        return in_recovery, timeline, lsn
 
     def _get_local_timeline_lsn(self):
-        if self._postgresql.is_running():  # if postgres is running - get timeline and lsn from replication connection
-            timeline, lsn = self._postgresql.get_local_timeline_lsn_from_replication_connection()
+        if self._postgresql.is_running():  # if postgres is running - get timeline from replication connection
+            in_recovery = True
+            timeline = self._postgresql.received_timeline() or self._postgresql.get_replica_timeline()
+            lsn = self._postgresql.replayed_location()
         else:  # otherwise analyze pg_controldata output
-            timeline, lsn = self._get_local_timeline_lsn_from_controldata()
-        logger.info('Local timeline=%s lsn=%s', timeline, lsn)
-        return timeline, lsn
+            in_recovery, timeline, lsn = self._get_local_timeline_lsn_from_controldata()
+
+        log_lsn = format_lsn(lsn) if isinstance(lsn, six.integer_types) else lsn
+        logger.info('Local timeline=%s lsn=%s', timeline, log_lsn)
+        return in_recovery, timeline, lsn
+
+    @staticmethod
+    def _log_master_history(history, i):
+        start = max(0, i - 3)
+        end = None if i + 4 >= len(history) else i + 2
+        history_show = []
+
+        def format_history_line(line):
+            return '{0}\t{1}\t{2}'.format(line[0], format_lsn(line[1]), line[2])
+
+        for line in history[start:end]:
+            history_show.append(format_history_line(line))
+
+        if line != history[-1]:
+            history_show.append('...')
+            history_show.append(format_history_line(history[-1]))
+
+        logger.info('master: history=%s', '\n'.join(history_show))
+
+    def _conn_kwargs(self, member, auth):
+        ret = member.conn_kwargs(auth)
+        if not ret.get('dbname'):
+            ret['dbname'] = self._postgresql.database
+        return ret
 
     def _check_timeline_and_lsn(self, leader):
-        local_timeline, local_lsn = self._get_local_timeline_lsn()
+        in_recovery, local_timeline, local_lsn = self._get_local_timeline_lsn()
         if local_timeline is None or local_lsn is None:
             return
 
-        if isinstance(leader, Leader):
-            if leader.member.data.get('role') != 'master':
-                return
-        # standby cluster
-        elif not self.check_leader_is_not_in_recovery(**leader.conn_kwargs(self._postgresql.config.replication)):
+        if isinstance(leader, Leader) and leader.member.data.get('role') != 'master':
+            return
+
+        if not self.check_leader_is_not_in_recovery(
+                self._conn_kwargs(leader, self._postgresql.config.rewind_credentials)):
             return
 
         history = need_rewind = None
@@ -108,25 +176,36 @@ class Rewind(object):
                 logger.info('master_timeline=%s', master_timeline)
                 if local_timeline > master_timeline:  # Not always supported by pg_rewind
                     need_rewind = True
-                elif master_timeline > 1:
-                    cur.execute('TIMELINE_HISTORY %s', (master_timeline,))
-                    history = bytes(cur.fetchone()[1]).decode('utf-8')
-                    logger.info('master: history=%s', history)
-                else:  # local_timeline == master_timeline == 1
+                elif local_timeline == master_timeline:
                     need_rewind = False
+                elif master_timeline > 1:
+                    cur.execute('TIMELINE_HISTORY {0}'.format(master_timeline))
+                    history = cur.fetchone()[1]
+                    if not isinstance(history, six.string_types):
+                        history = bytes(history).decode('utf-8')
+                    logger.debug('master: history=%s', history)
         except Exception:
             return logger.exception('Exception when working with master via replication connection')
 
         if history is not None:
-            for parent_timeline, switchpoint, _ in parse_history(history):
+            history = list(parse_history(history))
+            for i, (parent_timeline, switchpoint, _) in enumerate(history):
                 if parent_timeline == local_timeline:
-                    try:
-                        need_rewind = parse_lsn(local_lsn) >= switchpoint
-                    except (IndexError, ValueError):
-                        logger.exception('Exception when parsing lsn')
-                    break
+                    # We don't need to rewind when:
+                    # 1. for replica: replayed location is not ahead of switchpoint
+                    # 2. for the former primary: end of checkpoint record is the same as switchpoint
+                    if in_recovery:
+                        need_rewind = local_lsn > switchpoint
+                    elif local_lsn >= switchpoint:
+                        need_rewind = True
+                    else:
+                        need_rewind = switchpoint != self._get_checkpoint_end(local_timeline, local_lsn)
                 elif parent_timeline > local_timeline:
+                    need_rewind = True
                     break
+            else:
+                need_rewind = True
+            self._log_master_history(history, i)
 
         self._state = need_rewind and REWIND_STATUS.NEED or REWIND_STATUS.NOT_NEED
 
@@ -135,15 +214,17 @@ class Rewind(object):
             self._check_timeline_and_lsn(leader)
         return leader and leader.conn_url and self._state == REWIND_STATUS.NEED
 
-    def __checkpoint(self, task):
+    def __checkpoint(self, task, wakeup):
         try:
             result = self._postgresql.checkpoint()
         except Exception as e:
             result = 'Exception: ' + str(e)
         with task:
             task.complete(not bool(result))
+            if task.result:
+                wakeup()
 
-    def ensure_checkpoint_after_promote(self):
+    def ensure_checkpoint_after_promote(self, wakeup):
         """After promote issue a CHECKPOINT from a new thread and asynchronously check the result.
         In case if CHECKPOINT failed, just check that timeline in pg_control was updated."""
 
@@ -151,38 +232,101 @@ class Rewind(object):
             with self._checkpoint_task_lock:
                 if self._checkpoint_task:
                     with self._checkpoint_task:
-                        if self._checkpoint_task.result:
+                        if self._checkpoint_task.result is not None:
                             self._state = REWIND_STATUS.CHECKPOINT
-                        if self._checkpoint_task.result is not False:
-                            return
+                            self._checkpoint_task = None
+                elif self._postgresql.get_master_timeline() == self._postgresql.pg_control_timeline():
+                    self._state = REWIND_STATUS.CHECKPOINT
                 else:
                     self._checkpoint_task = CriticalTask()
-                    return Thread(target=self.__checkpoint, args=(self._checkpoint_task,)).start()
-
-            if self._postgresql.get_master_timeline() == self._postgresql.pg_control_timeline():
-                self._state = REWIND_STATUS.CHECKPOINT
+                    Thread(target=self.__checkpoint, args=(self._checkpoint_task, wakeup)).start()
 
     def checkpoint_after_promote(self):
         return self._state == REWIND_STATUS.CHECKPOINT
 
+    def _fetch_missing_wal(self, restore_command, wal_filename):
+        cmd = ''
+        length = len(restore_command)
+        i = 0
+        while i < length:
+            if restore_command[i] == '%' and i + 1 < length:
+                i += 1
+                if restore_command[i] == 'p':
+                    cmd += os.path.join(self._postgresql.wal_dir, wal_filename)
+                elif restore_command[i] == 'f':
+                    cmd += wal_filename
+                elif restore_command[i] == 'r':
+                    cmd += '000000010000000000000001'
+                elif restore_command[i] == '%':
+                    cmd += '%'
+                else:
+                    cmd += '%'
+                    i -= 1
+            else:
+                cmd += restore_command[i]
+            i += 1
+
+        logger.info('Trying to fetch the missing wal: %s', cmd)
+        return self._postgresql.cancellable.call(shlex.split(cmd)) == 0
+
+    def _find_missing_wal(self, data):
+        # could not open file "$PGDATA/pg_wal/0000000A00006AA100000068": No such file or directory
+        pattern = 'could not open file "'
+        for line in data.decode('utf-8').split('\n'):
+            b = line.find(pattern)
+            if b > -1:
+                b += len(pattern)
+                e = line.find('": ', b)
+                if e > -1 and '/' in line[b:e]:
+                    waldir, wal_filename = line[b:e].rsplit('/', 1)
+                    if waldir.endswith('/pg_' + self._postgresql.wal_name) and len(wal_filename) == 24:
+                        return wal_filename
+
     def pg_rewind(self, r):
         # prepare pg_rewind connection
         env = self._postgresql.config.write_pgpass(r)
-        env['PGOPTIONS'] = '-c statement_timeout=0'
+        env.update(LANG='C', LC_ALL='C', PGOPTIONS='-c statement_timeout=0')
         dsn = self._postgresql.config.format_dsn(r, True)
         logger.info('running pg_rewind from %s', dsn)
-        try:
-            return self._postgresql.cancellable.call([self._postgresql.pgcommand('pg_rewind'), '-D',
-                                                      self._postgresql.data_dir, '--source-server', dsn], env=env) == 0
-        except OSError:
-            return False
+
+        restore_command = self._postgresql.config.get('recovery_conf', {}).get('restore_command') \
+            if self._postgresql.major_version < 120000 else self._postgresql.get_guc_value('restore_command')
+
+        cmd = [self._postgresql.pgcommand('pg_rewind')]
+        if self._postgresql.major_version >= 130000 and restore_command:
+            cmd.append('--restore-target-wal')
+        cmd.extend(['-D', self._postgresql.data_dir, '--source-server', dsn])
+
+        while True:
+            results = {}
+            ret = self._postgresql.cancellable.call(cmd, env=env, communicate=results)
+
+            logger.info('pg_rewind exit code=%s', ret)
+            if ret is None:
+                return False
+
+            logger.info(' stdout=%s', results['stdout'].decode('utf-8'))
+            logger.info(' stderr=%s', results['stderr'].decode('utf-8'))
+            if ret == 0:
+                return True
+
+            if not restore_command or self._postgresql.major_version >= 130000:
+                return False
+
+            missing_wal = self._find_missing_wal(results['stderr']) or self._find_missing_wal(results['stdout'])
+            if not missing_wal:
+                return False
+
+            if not self._fetch_missing_wal(restore_command, missing_wal):
+                logger.info('Failed to fetch WAL segment %s required for pg_rewind', missing_wal)
+                return False
 
     def execute(self, leader):
         if self._postgresql.is_running() and not self._postgresql.stop(checkpoint=False):
             return logger.warning('Can not run pg_rewind because postgres is still running')
 
         # prepare pg_rewind connection
-        r = leader.conn_kwargs(self._postgresql.config.rewind_credentials)
+        r = self._conn_kwargs(leader, self._postgresql.config.rewind_credentials)
 
         # 1. make sure that we are really trying to rewind from the master
         # 2. make sure that pg_control contains the new timeline by:
@@ -190,17 +334,17 @@ class Rewind(object):
         #   waiting until Patroni on the master will expose checkpoint_after_promote=True
         checkpoint_status = leader.checkpoint_after_promote if isinstance(leader, Leader) else None
         if checkpoint_status is None:  # master still runs the old Patroni
-            leader_status = self._postgresql.checkpoint(leader.conn_kwargs(self._postgresql.config.superuser))
+            leader_status = self._postgresql.checkpoint(self._conn_kwargs(leader, self._postgresql.config.superuser))
             if leader_status:
                 return logger.warning('Can not use %s for rewind: %s', leader.name, leader_status)
         elif not checkpoint_status:
             return logger.info('Waiting for checkpoint on %s before rewind', leader.name)
-        elif not self.check_leader_is_not_in_recovery(**r):
+        elif not self.check_leader_is_not_in_recovery(r):
             return
 
         if self.pg_rewind(r):
             self._state = REWIND_STATUS.SUCCESS
-        elif not self.check_leader_is_not_in_recovery(**r):
+        elif not self.check_leader_is_not_in_recovery(r):
             logger.warning('Failed to rewind because master %s become unreachable', leader.name)
         else:
             logger.error('Failed to rewind from healty master: %s', leader.name)
@@ -231,3 +375,56 @@ class Rewind(object):
     @property
     def failed(self):
         return self._state == REWIND_STATUS.FAILED
+
+    def read_postmaster_opts(self):
+        """returns the list of option names/values from postgres.opts, Empty dict if read failed or no file"""
+        result = {}
+        try:
+            with open(os.path.join(self._postgresql.data_dir, 'postmaster.opts')) as f:
+                data = f.read()
+                for opt in data.split('" "'):
+                    if '=' in opt and opt.startswith('--'):
+                        name, val = opt.split('=', 1)
+                        result[name.strip('-')] = val.rstrip('"\n')
+        except IOError:
+            logger.exception('Error when reading postmaster.opts')
+        return result
+
+    def single_user_mode(self, communicate=None, options=None):
+        """run a given command in a single-user mode. If the command is empty - then just start and stop"""
+        cmd = [self._postgresql.pgcommand('postgres'), '--single', '-D', self._postgresql.data_dir]
+        for opt, val in sorted((options or {}).items()):
+            cmd.extend(['-c', '{0}={1}'.format(opt, val)])
+        # need a database name to connect
+        cmd.append('template1')
+        return self._postgresql.cancellable.call(cmd, communicate=communicate)
+
+    def cleanup_archive_status(self):
+        status_dir = os.path.join(self._postgresql.wal_dir, 'archive_status')
+        try:
+            for f in os.listdir(status_dir):
+                path = os.path.join(status_dir, f)
+                try:
+                    if os.path.islink(path):
+                        os.unlink(path)
+                    elif os.path.isfile(path):
+                        os.remove(path)
+                except OSError:
+                    logger.exception('Unable to remove %s', path)
+        except OSError:
+            logger.exception('Unable to list %s', status_dir)
+
+    def ensure_clean_shutdown(self):
+        self.cleanup_archive_status()
+
+        # Start in a single user mode and stop to produce a clean shutdown
+        opts = self.read_postmaster_opts()
+        opts.update({'archive_mode': 'on', 'archive_command': 'false'})
+        self._postgresql.config.remove_recovery_conf()
+        output = {}
+        ret = self.single_user_mode(communicate=output, options=opts)
+        if ret != 0:
+            logger.error('Crash recovery finished with code=%s', ret)
+            logger.info(' stdout=%s', output['stdout'].decode('utf-8'))
+            logger.info(' stderr=%s', output['stderr'].decode('utf-8'))
+        return ret == 0 or None

patroni/postgresql/slots.py

@@ -1,14 +1,34 @@
+import errno
 import logging
+import os
+import shutil
 
-from patroni.postgresql.connection import get_connection_cursor
 from collections import defaultdict
+from contextlib import contextmanager
+
+from .connection import get_connection_cursor
+from .misc import format_lsn
+from ..psycopg import UndefinedFile
 
 logger = logging.getLogger(__name__)
 
 
-def compare_slots(s1, s2):
+def compare_slots(s1, s2, dbid='database'):
     return s1['type'] == s2['type'] and (s1['type'] == 'physical' or
-                                         s1['database'] == s2['database'] and s1['plugin'] == s2['plugin'])
+                                         s1.get(dbid) == s2.get(dbid) and s1['plugin'] == s2['plugin'])
+
+
+def fsync_dir(path):
+    if os.name != 'nt':
+        fd = os.open(path, os.O_DIRECTORY)
+        try:
+            os.fsync(fd)
+        except OSError as e:
+            # Some filesystems don't like fsyncing directories and raise EINVAL. Ignoring it is usually safe.
+            if e.errno != errno.EINVAL:
+                raise
+        finally:
+            os.close(fd)
 
 
 class SlotsHandler(object):
@@ -16,22 +36,75 @@ class SlotsHandler(object):
     def __init__(self, postgresql):
         self._postgresql = postgresql
         self._replication_slots = {}  # already existing replication slots
+        self._unready_logical_slots = set()
         self.schedule()
 
     def _query(self, sql, *params):
         return self._postgresql.query(sql, *params, retry=False)
 
+    @staticmethod
+    def _copy_items(src, dst, keys=None):
+        dst.update({key: src[key] for key in keys or ('datoid', 'catalog_xmin', 'confirmed_flush_lsn')})
+
+    def process_permanent_slots(self, slots):
+        """This methods solves three problems at once (I know, it is weird).
+
+        The cluster_info_query from `Postgresql` is executed every HA loop and returns
+        information about all replication slots that exists on the current host.
+        Based on this information we perform the following actions:
+        1. For the primary we want to expose to DCS permanent logical slots, therefore the method
+           builds (and returns) a dict, that maps permanent logical slot names and confirmed_flush_lsns.
+        2. This method also detects if one of the previously known permanent slots got missing and schedules resync.
+        3. Updates the local cache with the fresh catalog_xmin and confirmed_flush_lsn for every known slot.
+           This info is used when performing the check of logical slot readiness on standbys.
+        """
+        ret = {}
+
+        slots = {slot['slot_name']: slot for slot in slots or []}
+        if slots:
+            for name, value in slots.items():
+                if name in self._replication_slots:
+                    if compare_slots(value, self._replication_slots[name], 'datoid'):
+                        if value['type'] == 'logical':
+                            ret[name] = value['confirmed_flush_lsn']
+                            self._copy_items(value, self._replication_slots[name])
+                    else:
+                        self._schedule_load_slots = True
+
+        # It could happen that the slots was deleted in the background, we want to detect this case
+        if any(name not in slots for name in self._replication_slots.keys()):
+            self._schedule_load_slots = True
+
+        return ret
+
     def load_replication_slots(self):
         if self._postgresql.major_version >= 90400 and self._schedule_load_slots:
             replication_slots = {}
-            cursor = self._query('SELECT slot_name, slot_type, plugin, database FROM pg_catalog.pg_replication_slots')
+            extra = ", catalog_xmin, pg_catalog.pg_wal_lsn_diff(confirmed_flush_lsn, '0/0')::bigint"\
+                if self._postgresql.major_version >= 100000 else ""
+            skip_temp_slots = ' WHERE NOT temporary' if self._postgresql.major_version >= 100000 else ''
+            cursor = self._query('SELECT slot_name, slot_type, plugin, database, datoid'
+                                 '{0} FROM pg_catalog.pg_replication_slots{1}'.format(extra, skip_temp_slots))
             for r in cursor:
                 value = {'type': r[1]}
                 if r[1] == 'logical':
-                    value.update({'plugin': r[2], 'database': r[3]})
+                    value.update(plugin=r[2], database=r[3], datoid=r[4])
+                    if self._postgresql.major_version >= 100000:
+                        value.update(catalog_xmin=r[5], confirmed_flush_lsn=r[6])
                 replication_slots[r[0]] = value
             self._replication_slots = replication_slots
             self._schedule_load_slots = False
+            if self._force_readiness_check:
+                self._unready_logical_slots = set(n for n, v in replication_slots.items() if v['type'] == 'logical')
+                self._force_readiness_check = False
+
+    def ignore_replication_slot(self, cluster, name):
+        slot = self._replication_slots[name]
+        for matcher in cluster.config.ignore_slots_matchers:
+            if ((matcher.get("name") is None or matcher["name"] == name)
+               and all(not matcher.get(a) or matcher[a] == slot.get(a) for a in ('database', 'plugin', 'type'))):
+                return True
+        return False
 
     def drop_replication_slot(self, name):
         cursor = self._query(('SELECT pg_catalog.pg_drop_replication_slot(%s) WHERE EXISTS (SELECT 1 ' +
@@ -39,65 +112,192 @@ class SlotsHandler(object):
         # In normal situation rowcount should be 1, otherwise either slot doesn't exists or it is still active
         return cursor.rowcount == 1
 
-    def sync_replication_slots(self, cluster):
-        if self._postgresql.major_version >= 90400:
+    def _drop_incorrect_slots(self, cluster, slots):
+        # drop old replication slots which are not presented in desired slots
+        for name in set(self._replication_slots) - set(slots):
+            if not self.ignore_replication_slot(cluster, name) and not self.drop_replication_slot(name):
+                logger.error("Failed to drop replication slot '%s'", name)
+                self._schedule_load_slots = True
+
+        for name, value in slots.items():
+            if name in self._replication_slots and not compare_slots(value, self._replication_slots[name]):
+                logger.info("Trying to drop replication slot '%s' because value is changing from %s to %s",
+                            name, self._replication_slots[name], value)
+                if self.drop_replication_slot(name):
+                    self._replication_slots.pop(name)
+                else:
+                    logger.error("Failed to drop replication slot '%s'", name)
+                    self._schedule_load_slots = True
+
+    def _ensure_physical_slots(self, slots):
+        immediately_reserve = ', true' if self._postgresql.major_version >= 90600 else ''
+        for name, value in slots.items():
+            if name not in self._replication_slots and value['type'] == 'physical':
+                try:
+                    self._query(("SELECT pg_catalog.pg_create_physical_replication_slot(%s{0})" +
+                                 " WHERE NOT EXISTS (SELECT 1 FROM pg_catalog.pg_replication_slots" +
+                                 " WHERE slot_type = 'physical' AND slot_name = %s)").format(
+                                     immediately_reserve), name, name)
+                except Exception:
+                    logger.exception("Failed to create physical replication slot '%s'", name)
+                self._schedule_load_slots = True
+
+    @contextmanager
+    def _get_local_connection_cursor(self, **kwargs):
+        conn_kwargs = self._postgresql.config.local_connect_kwargs
+        conn_kwargs.update(kwargs)
+        with get_connection_cursor(**conn_kwargs) as cur:
+            yield cur
+
+    def _ensure_logical_slots_primary(self, slots):
+        # Group logical slots to be created by database name
+        logical_slots = defaultdict(dict)
+        for name, value in slots.items():
+            if value['type'] == 'logical':
+                # If the logical already exists, copy some information about it into the original structure
+                if self._replication_slots.get(name, {}).get('datoid'):
+                    self._copy_items(self._replication_slots[name], value)
+                else:
+                    logical_slots[value['database']][name] = value
+
+        # Create new logical slots
+        for database, values in logical_slots.items():
+            with self._get_local_connection_cursor(dbname=database) as cur:
+                for name, value in values.items():
+                    try:
+                        cur.execute("SELECT pg_catalog.pg_create_logical_replication_slot(%s, %s)" +
+                                    " WHERE NOT EXISTS (SELECT 1 FROM pg_catalog.pg_replication_slots" +
+                                    " WHERE slot_type = 'logical' AND slot_name = %s)",
+                                    (name, value['plugin'], name))
+                    except Exception as e:
+                        logger.error("Failed to create logical replication slot '%s' plugin='%s': %r",
+                                     name, value['plugin'], e)
+                        slots.pop(name)
+                    self._schedule_load_slots = True
+
+    def _ensure_logical_slots_replica(self, cluster, slots):
+        advance_slots = defaultdict(dict)  # Group logical slots to be advanced by database name
+        create_slots = []  # And collect logical slots to be created on the replica
+        for name, value in slots.items():
+            if value['type'] == 'logical':
+                # If the logical already exists, copy some information about it into the original structure
+                if self._replication_slots.get(name, {}).get('datoid'):
+                    self._copy_items(self._replication_slots[name], value)
+                    if name in cluster.slots:
+                        try:  # Skip slots that doesn't need to be advanced
+                            if value['confirmed_flush_lsn'] < int(cluster.slots[name]):
+                                advance_slots[value['database']][name] = value
+                        except Exception as e:
+                            logger.error('Failed to parse "%s": %r', cluster.slots[name], e)
+                elif name in cluster.slots:  # We want to copy only slots with feedback in a DCS
+                    create_slots.append(name)
+
+        # Advance logical slots
+        for database, values in advance_slots.items():
+            with self._get_local_connection_cursor(dbname=database, options='-c statement_timeout=0') as cur:
+                for name, value in values.items():
+                    try:
+                        cur.execute("SELECT pg_catalog.pg_replication_slot_advance(%s, %s)",
+                                    (name, format_lsn(int(cluster.slots[name]))))
+                    except Exception as e:
+                        logger.error("Failed to advance logical replication slot '%s': %r", name, e)
+                        if isinstance(e, UndefinedFile):
+                            create_slots.append(name)
+                        self._schedule_load_slots = True
+        return create_slots
+
+    def sync_replication_slots(self, cluster, nofailover, replicatefrom=None):
+        ret = None
+        if self._postgresql.major_version >= 90400 and cluster.config:
             try:
                 self.load_replication_slots()
 
-                slots = cluster.get_replication_slots(self._postgresql.name, self._postgresql.role)
+                slots = cluster.get_replication_slots(self._postgresql.name, self._postgresql.role,
+                                                      nofailover, self._postgresql.major_version, True)
 
-                # drop old replication slots which are not presented in desired slots
-                for name in set(self._replication_slots) - set(slots):
-                    if not self.drop_replication_slot(name):
-                        logger.error("Failed to drop replication slot '%s'", name)
-                        self._schedule_load_slots = True
+                self._drop_incorrect_slots(cluster, slots)
 
-                immediately_reserve = ', true' if self._postgresql.major_version >= 90600 else ''
+                self._ensure_physical_slots(slots)
 
-                logical_slots = defaultdict(dict)
-                for name, value in slots.items():
-                    if name in self._replication_slots and not compare_slots(value, self._replication_slots[name]):
-                        logger.info("Trying to drop replication slot '%s' because value is changing from %s to %s",
-                                    name, self._replication_slots[name], value)
-                        if not self.drop_replication_slot(name):
-                            logger.error("Failed to drop replication slot '%s'", name)
-                            self._schedule_load_slots = True
-                            continue
-                        self._replication_slots.pop(name)
-                    if name not in self._replication_slots:
-                        if value['type'] == 'physical':
-                            try:
-                                self._query(("SELECT pg_catalog.pg_create_physical_replication_slot(%s{0})" +
-                                             " WHERE NOT EXISTS (SELECT 1 FROM pg_catalog.pg_replication_slots" +
-                                             " WHERE slot_type = 'physical' AND slot_name = %s)").format(
-                                                 immediately_reserve), name, name)
-                            except Exception:
-                                logger.exception("Failed to create physical replication slot '%s'", name)
-                                self._schedule_load_slots = True
-                        elif value['type'] == 'logical' and name not in self._replication_slots:
-                            logical_slots[value['database']][name] = value
+                if self._postgresql.is_leader():
+                    self._unready_logical_slots.clear()
+                    self._ensure_logical_slots_primary(slots)
+                elif cluster.slots and slots:
+                    self.check_logical_slots_readiness(cluster, nofailover, replicatefrom)
+
+                    ret = self._ensure_logical_slots_replica(cluster, slots)
 
-                # create new logical slots
-                for database, values in logical_slots.items():
-                    conn_kwargs = self._postgresql.config.local_connect_kwargs
-                    conn_kwargs['database'] = database
-                    with get_connection_cursor(**conn_kwargs) as cur:
-                        for name, value in values.items():
-                            try:
-                                cur.execute("SELECT pg_catalog.pg_create_logical_replication_slot(%s, %s)" +
-                                            " WHERE NOT EXISTS (SELECT 1 FROM pg_catalog.pg_replication_slots" +
-                                            " WHERE slot_type = 'logical' AND slot_name = %s)",
-                                            (name, value['plugin'], name))
-                            except Exception:
-                                logger.exception("Failed to create logical replication slot '%s' plugin='%s'",
-                                                 name, value['plugin'])
-                                self._schedule_load_slots = True
                 self._replication_slots = slots
             except Exception:
                 logger.exception('Exception when changing replication slots')
                 self._schedule_load_slots = True
+        return ret
+
+    @contextmanager
+    def _get_leader_connection_cursor(self, leader):
+        conn_kwargs = leader.conn_kwargs(self._postgresql.config.rewind_credentials)
+        conn_kwargs['dbname'] = self._postgresql.database
+        with get_connection_cursor(connect_timeout=3, options="-c statement_timeout=2000", **conn_kwargs) as cur:
+            yield cur
+
+    def check_logical_slots_readiness(self, cluster, nofailover, replicatefrom):
+        if self._unready_logical_slots:
+            slot_name = cluster.get_my_slot_name_on_primary(self._postgresql.name, replicatefrom)
+            try:
+                with self._get_leader_connection_cursor(cluster.leader) as cur:
+                    cur.execute("SELECT catalog_xmin FROM pg_catalog.pg_get_replication_slots()"
+                                " WHERE NOT pg_catalog.pg_is_in_recovery() AND slot_name = %s", (slot_name,))
+                    if cur.rowcount < 1:
+                        return logger.warning('Physical slot %s does not exist on the primary', slot_name)
+                    catalog_xmin = cur.fetchone()[0]
+            except Exception as e:
+                return logger.error("Failed to check %s physical slot on the primary: %r", slot_name, e)
+        for name in list(self._unready_logical_slots):
+            value = self._replication_slots.get(name)
+            if not value or catalog_xmin <= value['catalog_xmin']:
+                self._unready_logical_slots.remove(name)
+                if value:
+                    logger.info('Logical slot %s is safe to be used after a failover', name)
+
+    def copy_logical_slots(self, leader, slots):
+        with self._get_leader_connection_cursor(leader) as cur:
+            try:
+                cur.execute("SELECT slot_name, catalog_xmin, "
+                            "pg_catalog.pg_wal_lsn_diff(confirmed_flush_lsn, '0/0')::bigint, "
+                            "pg_catalog.pg_read_binary_file('pg_replslot/' || slot_name || '/state')"
+                            " FROM pg_catalog.pg_get_replication_slots() WHERE NOT pg_catalog.pg_is_in_recovery()"
+                            " AND slot_name = ANY(%s)", (slots,))
+                slots = {r[0]: {'catalog_xmin': r[1], 'confirmed_flush_lsn': r[2], 'data': r[3]} for r in cur}
+            except Exception as e:
+                logger.error("Failed to copy logical slots from the %s via postgresql connection: %r", leader.name, e)
+
+        if isinstance(slots, dict) and self._postgresql.stop():
+            pg_replslot_dir = os.path.join(self._postgresql.data_dir, 'pg_replslot')
+            for name, value in slots.items():
+                slot_dir = os.path.join(pg_replslot_dir, name)
+                slot_tmp_dir = slot_dir + '.tmp'
+                if os.path.exists(slot_tmp_dir):
+                    shutil.rmtree(slot_tmp_dir)
+                os.makedirs(slot_tmp_dir)
+                fsync_dir(slot_tmp_dir)
+                with open(os.path.join(slot_tmp_dir, 'state'), 'wb') as f:
+                    f.write(value['data'])
+                    f.flush()
+                    os.fsync(f.fileno())
+                if os.path.exists(slot_dir):
+                    shutil.rmtree(slot_dir)
+                os.rename(slot_tmp_dir, slot_dir)
+                fsync_dir(slot_dir)
+                self._unready_logical_slots.add(name)
+            fsync_dir(pg_replslot_dir)
+            self._postgresql.start()
 
     def schedule(self, value=None):
         if value is None:
             value = self._postgresql.major_version >= 90400
-        self._schedule_load_slots = value
+        self._schedule_load_slots = self._force_readiness_check = value
+
+    def on_promote(self):
+        if self._unready_logical_slots:
+            logger.warning('Logical replication slots that might be unsafe to use after promote: %s',
+                           self._unready_logical_slots)

patroni/postgresql/validator.py

@@ -0,0 +1,535 @@
+import abc
+import logging
+import six
+
+from collections import namedtuple
+from urllib3.response import HTTPHeaderDict
+
+from ..utils import parse_bool, parse_int, parse_real
+
+logger = logging.getLogger(__name__)
+
+
+class CaseInsensitiveDict(HTTPHeaderDict):
+
+    def add(self, key, val):
+        self[key] = val
+
+    def __getitem__(self, key):
+        return self._container[key.lower()][1]
+
+    def __repr__(self):
+        return str(dict(self.items()))
+
+    def copy(self):
+        return CaseInsensitiveDict(self._container.values())
+
+
+class Bool(namedtuple('Bool', 'version_from,version_till')):
+
+    @staticmethod
+    def transform(name, value):
+        if parse_bool(value) is not None:
+            return value
+        logger.warning('Removing bool parameter=%s from the config due to the invalid value=%s', name, value)
+
+
+@six.add_metaclass(abc.ABCMeta)
+class Number(namedtuple('Number', 'version_from,version_till,min_val,max_val,unit')):
+
+    @staticmethod
+    @abc.abstractmethod
+    def parse(value, unit):
+        """parse value"""
+
+    def transform(self, name, value):
+        num_value = self.parse(value, self.unit)
+        if num_value is not None:
+            if num_value < self.min_val:
+                logger.warning('Value=%s of parameter=%s is too low, increasing to %s%s',
+                               value, name, self.min_val, self.unit or '')
+                return self.min_val
+            if num_value > self.max_val:
+                logger.warning('Value=%s of parameter=%s is too big, decreasing to %s%s',
+                               value, name, self.max_val, self.unit or '')
+                return self.max_val
+            return value
+        logger.warning('Removing %s parameter=%s from the config due to the invalid value=%s',
+                       self.__class__.__name__.lower(), name, value)
+
+
+class Integer(Number):
+
+    @staticmethod
+    def parse(value, unit):
+        return parse_int(value, unit)
+
+
+class Real(Number):
+
+    @staticmethod
+    def parse(value, unit):
+        return parse_real(value, unit)
+
+
+class Enum(namedtuple('Enum', 'version_from,version_till,possible_values')):
+
+    def transform(self, name, value):
+        if str(value).lower() in self.possible_values:
+            return value
+        logger.warning('Removing enum parameter=%s from the config due to the invalid value=%s', name, value)
+
+
+class EnumBool(Enum):
+
+    def transform(self, name, value):
+        if parse_bool(value) is not None:
+            return value
+        return super(EnumBool, self).transform(name, value)
+
+
+class String(namedtuple('String', 'version_from,version_till')):
+
+    @staticmethod
+    def transform(name, value):
+        return value
+
+
+# Format:
+#  key - parameter name
+#  value - tuple or multiple tuples if something was changing in GUC across postgres versions
+parameters = CaseInsensitiveDict({
+    'allow_system_table_mods': Bool(90300, None),
+    'application_name': String(90300, None),
+    'archive_command': String(90300, None),
+    'archive_mode': (
+        Bool(90300, 90500),
+        EnumBool(90500, None, ('always',))
+    ),
+    'archive_timeout': Integer(90300, None, 0, 1073741823, 's'),
+    'array_nulls': Bool(90300, None),
+    'authentication_timeout': Integer(90300, None, 1, 600, 's'),
+    'autovacuum': Bool(90300, None),
+    'autovacuum_analyze_scale_factor': Real(90300, None, 0, 100, None),
+    'autovacuum_analyze_threshold': Integer(90300, None, 0, 2147483647, None),
+    'autovacuum_freeze_max_age': Integer(90300, None, 100000, 2000000000, None),
+    'autovacuum_max_workers': (
+        Integer(90300, 90600, 1, 8388607, None),
+        Integer(90600, None, 1, 262143, None)
+    ),
+    'autovacuum_multixact_freeze_max_age': Integer(90300, None, 10000, 2000000000, None),
+    'autovacuum_naptime': Integer(90300, None, 1, 2147483, 's'),
+    'autovacuum_vacuum_cost_delay': (
+        Integer(90300, 120000, -1, 100, 'ms'),
+        Real(120000, None, -1, 100, 'ms')
+    ),
+    'autovacuum_vacuum_cost_limit': Integer(90300, None, -1, 10000, None),
+    'autovacuum_vacuum_insert_scale_factor': Real(130000, None, 0, 100, None),
+    'autovacuum_vacuum_insert_threshold': Integer(130000, None, -1, 2147483647, None),
+    'autovacuum_vacuum_scale_factor': Real(90300, None, 0, 100, None),
+    'autovacuum_vacuum_threshold': Integer(90300, None, 0, 2147483647, None),
+    'autovacuum_work_mem': Integer(90400, None, -1, 2147483647, 'kB'),
+    'backend_flush_after': Integer(90600, None, 0, 256, '8kB'),
+    'backslash_quote': EnumBool(90300, None, ('safe_encoding',)),
+    'backtrace_functions': String(130000, None),
+    'bgwriter_delay': Integer(90300, None, 10, 10000, 'ms'),
+    'bgwriter_flush_after': Integer(90600, None, 0, 256, '8kB'),
+    'bgwriter_lru_maxpages': (
+        Integer(90300, 100000, 0, 1000, None),
+        Integer(100000, None, 0, 1073741823, None)
+    ),
+    'bgwriter_lru_multiplier': Real(90300, None, 0, 10, None),
+    'bonjour': Bool(90300, None),
+    'bonjour_name': String(90300, None),
+    'bytea_output': Enum(90300, None, ('escape', 'hex')),
+    'check_function_bodies': Bool(90300, None),
+    'checkpoint_completion_target': Real(90300, None, 0, 1, None),
+    'checkpoint_flush_after': Integer(90600, None, 0, 256, '8kB'),
+    'checkpoint_segments': Integer(90300, 90500, 1, 2147483647, None),
+    'checkpoint_timeout': (
+        Integer(90300, 90600, 30, 3600, 's'),
+        Integer(90600, None, 30, 86400, 's')
+    ),
+    'checkpoint_warning': Integer(90300, None, 0, 2147483647, 's'),
+    'client_connection_check_interval': Integer(140000, None, '0', '2147483647', 'ms'),
+    'client_encoding': String(90300, None),
+    'client_min_messages': Enum(90300, None, ('debug5', 'debug4', 'debug3', 'debug2',
+                                              'debug1', 'log', 'notice', 'warning', 'error')),
+    'cluster_name': String(90500, None),
+    'commit_delay': Integer(90300, None, 0, 100000, None),
+    'commit_siblings': Integer(90300, None, 0, 1000, None),
+    'compute_query_id': EnumBool(140000, None, ('auto',)),
+    'config_file': String(90300, None),
+    'constraint_exclusion': EnumBool(90300, None, ('partition',)),
+    'cpu_index_tuple_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'cpu_operator_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'cpu_tuple_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'cursor_tuple_fraction': Real(90300, None, 0, 1, None),
+    'data_directory': String(90300, None),
+    'data_sync_retry': Bool(90400, None),
+    'DateStyle': String(90300, None),
+    'db_user_namespace': Bool(90300, None),
+    'deadlock_timeout': Integer(90300, None, 1, 2147483647, 'ms'),
+    'debug_pretty_print': Bool(90300, None),
+    'debug_print_parse': Bool(90300, None),
+    'debug_print_plan': Bool(90300, None),
+    'debug_print_rewritten': Bool(90300, None),
+    'default_statistics_target': Integer(90300, None, 1, 10000, None),
+    'default_table_access_method': String(120000, None),
+    'default_tablespace': String(90300, None),
+    'default_text_search_config': String(90300, None),
+    'default_toast_compression': Enum(140000, None, ('pglz', 'lz4')),
+    'default_transaction_deferrable': Bool(90300, None),
+    'default_transaction_isolation': Enum(90300, None, ('serializable', 'repeatable read',
+                                                        'read committed', 'read uncommitted')),
+    'default_transaction_read_only': Bool(90300, None),
+    'default_with_oids': Bool(90300, 120000),
+    'dynamic_library_path': String(90300, None),
+    'dynamic_shared_memory_type': (
+        Enum(90400, 120000, ('posix', 'sysv', 'mmap', 'none')),
+        Enum(120000, None, ('posix', 'sysv', 'mmap'))
+    ),
+    'effective_cache_size': Integer(90300, None, 1, 2147483647, '8kB'),
+    'effective_io_concurrency': Integer(90300, None, 0, 1000, None),
+    'enable_async_append': Bool(140000, None),
+    'enable_bitmapscan': Bool(90300, None),
+    'enable_gathermerge': Bool(100000, None),
+    'enable_hashagg': Bool(90300, None),
+    'enable_hashjoin': Bool(90300, None),
+    'enable_incremental_sort': Bool(130000, None),
+    'enable_indexonlyscan': Bool(90300, None),
+    'enable_indexscan': Bool(90300, None),
+    'enable_material': Bool(90300, None),
+    'enable_mergejoin': Bool(90300, None),
+    'enable_nestloop': Bool(90300, None),
+    'enable_parallel_append': Bool(110000, None),
+    'enable_parallel_hash': Bool(110000, None),
+    'enable_partition_pruning': Bool(110000, None),
+    'enable_partitionwise_aggregate': Bool(110000, None),
+    'enable_partitionwise_join': Bool(110000, None),
+    'enable_seqscan': Bool(90300, None),
+    'enable_sort': Bool(90300, None),
+    'enable_tidscan': Bool(90300, None),
+    'escape_string_warning': Bool(90300, None),
+    'event_source': String(90300, None),
+    'exit_on_error': Bool(90300, None),
+    'extension_destdir': String(140000, None),
+    'external_pid_file': String(90300, None),
+    'extra_float_digits': Integer(90300, None, -15, 3, None),
+    'force_parallel_mode': EnumBool(90600, None, ('regress',)),
+    'from_collapse_limit': Integer(90300, None, 1, 2147483647, None),
+    'fsync': Bool(90300, None),
+    'full_page_writes': Bool(90300, None),
+    'geqo': Bool(90300, None),
+    'geqo_effort': Integer(90300, None, 1, 10, None),
+    'geqo_generations': Integer(90300, None, 0, 2147483647, None),
+    'geqo_pool_size': Integer(90300, None, 0, 2147483647, None),
+    'geqo_seed': Real(90300, None, 0, 1, None),
+    'geqo_selection_bias': Real(90300, None, 1.5, 2, None),
+    'geqo_threshold': Integer(90300, None, 2, 2147483647, None),
+    'gin_fuzzy_search_limit': Integer(90300, None, 0, 2147483647, None),
+    'gin_pending_list_limit': Integer(90500, None, 64, 2147483647, 'kB'),
+    'hash_mem_multiplier': Real(130000, None, 1, 1000, None),
+    'hba_file': String(90300, None),
+    'hot_standby': Bool(90300, None),
+    'hot_standby_feedback': Bool(90300, None),
+    'huge_pages': EnumBool(90400, None, ('try',)),
+    'huge_page_size': Integer(140000, None, '0', '2147483647', 'kB'),
+    'ident_file': String(90300, None),
+    'idle_in_transaction_session_timeout': Integer(90600, None, 0, 2147483647, 'ms'),
+    'idle_session_timeout': Integer(140000, None, '0', '2147483647', 'ms'),
+    'ignore_checksum_failure': Bool(90300, None),
+    'ignore_invalid_pages': Bool(130000, None),
+    'ignore_system_indexes': Bool(90300, None),
+    'IntervalStyle': Enum(90300, None, ('postgres', 'postgres_verbose', 'sql_standard', 'iso_8601')),
+    'jit': Bool(110000, None),
+    'jit_above_cost': Real(110000, None, -1, 1.79769e+308, None),
+    'jit_debugging_support': Bool(110000, None),
+    'jit_dump_bitcode': Bool(110000, None),
+    'jit_expressions': Bool(110000, None),
+    'jit_inline_above_cost': Real(110000, None, -1, 1.79769e+308, None),
+    'jit_optimize_above_cost': Real(110000, None, -1, 1.79769e+308, None),
+    'jit_profiling_support': Bool(110000, None),
+    'jit_provider': String(110000, None),
+    'jit_tuple_deforming': Bool(110000, None),
+    'join_collapse_limit': Integer(90300, None, 1, 2147483647, None),
+    'krb_caseins_users': Bool(90300, None),
+    'krb_server_keyfile': String(90300, None),
+    'krb_srvname': String(90300, 90400),
+    'lc_messages': String(90300, None),
+    'lc_monetary': String(90300, None),
+    'lc_numeric': String(90300, None),
+    'lc_time': String(90300, None),
+    'listen_addresses': String(90300, None),
+    'local_preload_libraries': String(90300, None),
+    'lock_timeout': Integer(90300, None, 0, 2147483647, 'ms'),
+    'lo_compat_privileges': Bool(90300, None),
+    'log_autovacuum_min_duration': Integer(90300, None, -1, 2147483647, 'ms'),
+    'log_checkpoints': Bool(90300, None),
+    'log_connections': Bool(90300, None),
+    'log_destination': String(90300, None),
+    'log_directory': String(90300, None),
+    'log_disconnections': Bool(90300, None),
+    'log_duration': Bool(90300, None),
+    'log_error_verbosity': Enum(90300, None, ('terse', 'default', 'verbose')),
+    'log_executor_stats': Bool(90300, None),
+    'log_file_mode': Integer(90300, None, 0, 511, None),
+    'log_filename': String(90300, None),
+    'logging_collector': Bool(90300, None),
+    'log_hostname': Bool(90300, None),
+    'logical_decoding_work_mem': Integer(130000, None, 64, 2147483647, 'kB'),
+    'log_line_prefix': String(90300, None),
+    'log_lock_waits': Bool(90300, None),
+    'log_min_duration_sample': Integer(130000, None, -1, 2147483647, 'ms'),
+    'log_min_duration_statement': Integer(90300, None, -1, 2147483647, 'ms'),
+    'log_min_error_statement': Enum(90300, None, ('debug5', 'debug4', 'debug3', 'debug2', 'debug1', 'info',
+                                                  'notice', 'warning', 'error', 'log', 'fatal', 'panic')),
+    'log_min_messages': Enum(90300, None, ('debug5', 'debug4', 'debug3', 'debug2', 'debug1', 'info',
+                                           'notice', 'warning', 'error', 'log', 'fatal', 'panic')),
+    'log_parameter_max_length': Integer(130000, None, -1, 1073741823, 'B'),
+    'log_parameter_max_length_on_error': Integer(130000, None, -1, 1073741823, 'B'),
+    'log_parser_stats': Bool(90300, None),
+    'log_planner_stats': Bool(90300, None),
+    'log_recovery_conflict_waits': Bool(140000, None),
+    'log_replication_commands': Bool(90500, None),
+    'log_rotation_age': Integer(90300, None, 0, 35791394, 'min'),
+    'log_rotation_size': Integer(90300, None, 0, 2097151, 'kB'),
+    'log_statement': Enum(90300, None, ('none', 'ddl', 'mod', 'all')),
+    'log_statement_sample_rate': Real(130000, None, 0, 1, None),
+    'log_statement_stats': Bool(90300, None),
+    'log_temp_files': Integer(90300, None, -1, 2147483647, 'kB'),
+    'log_timezone': String(90300, None),
+    'log_transaction_sample_rate': Real(120000, None, 0, 1, None),
+    'log_truncate_on_rotation': Bool(90300, None),
+    'maintenance_io_concurrency': Integer(130000, None, 0, 1000, None),
+    'maintenance_work_mem': Integer(90300, None, 1024, 2147483647, 'kB'),
+    'max_connections': (
+        Integer(90300, 90600, 1, 8388607, None),
+        Integer(90600, None, 1, 262143, None)
+    ),
+    'max_files_per_process': (
+        Integer(90300, 130000, 25, 2147483647, None),
+        Integer(130000, None, 64, 2147483647, None)
+    ),
+    'max_locks_per_transaction': Integer(90300, None, 10, 2147483647, None),
+    'max_logical_replication_workers': Integer(100000, None, 0, 262143, None),
+    'max_parallel_maintenance_workers': Integer(110000, None, 0, 1024, None),
+    'max_parallel_workers': Integer(100000, None, 0, 1024, None),
+    'max_parallel_workers_per_gather': Integer(90600, None, 0, 1024, None),
+    'max_pred_locks_per_page': Integer(100000, None, 0, 2147483647, None),
+    'max_pred_locks_per_relation': Integer(100000, None, -2147483648, 2147483647, None),
+    'max_pred_locks_per_transaction': Integer(90300, None, 10, 2147483647, None),
+    'max_prepared_transactions': (
+        Integer(90300, 90600, 0, 8388607, None),
+        Integer(90600, None, 0, 262143, None)
+    ),
+    'max_replication_slots': (
+        Integer(90400, 90600, 0, 8388607, None),
+        Integer(90600, None, 0, 262143, None)
+    ),
+    'max_slot_wal_keep_size': Integer(130000, None, -1, 2147483647, 'MB'),
+    'max_stack_depth': Integer(90300, None, 100, 2147483647, 'kB'),
+    'max_standby_archive_delay': Integer(90300, None, -1, 2147483647, 'ms'),
+    'max_standby_streaming_delay': Integer(90300, None, -1, 2147483647, 'ms'),
+    'max_sync_workers_per_subscription': Integer(100000, None, 0, 262143, None),
+    'max_wal_senders': (
+        Integer(90300, 90600, 0, 8388607, None),
+        Integer(90600, None, 0, 262143, None)
+    ),
+    'max_wal_size': (
+        Integer(90500, 100000, 2, 2147483647, '16MB'),
+        Integer(100000, None, 2, 2147483647, 'MB')
+    ),
+    'max_worker_processes': (
+        Integer(90400, 90600, 1, 8388607, None),
+        Integer(90600, None, 0, 262143, None)
+    ),
+    'min_dynamic_shared_memory': Integer(140000, None, '0', '2147483647', 'MB'),
+    'min_parallel_index_scan_size': Integer(100000, None, 0, 715827882, '8kB'),
+    'min_parallel_relation_size': Integer(90600, 100000, 0, 715827882, '8kB'),
+    'min_parallel_table_scan_size': Integer(100000, None, 0, 715827882, '8kB'),
+    'min_wal_size': (
+        Integer(90500, 100000, 2, 2147483647, '16MB'),
+        Integer(100000, None, 2, 2147483647, 'MB')
+    ),
+    'old_snapshot_threshold': Integer(90600, None, -1, 86400, 'min'),
+    'operator_precedence_warning': Bool(90500, 140000),
+    'parallel_leader_participation': Bool(110000, None),
+    'parallel_setup_cost': Real(90600, None, 0, 1.79769e+308, None),
+    'parallel_tuple_cost': Real(90600, None, 0, 1.79769e+308, None),
+    'password_encryption': (
+        Bool(90300, 100000),
+        Enum(100000, None, ('md5', 'scram-sha-256'))
+    ),
+    'plan_cache_mode': Enum(120000, None, ('auto', 'force_generic_plan', 'force_custom_plan')),
+    'port': Integer(90300, None, 1, 65535, None),
+    'post_auth_delay': Integer(90300, None, 0, 2147, 's'),
+    'pre_auth_delay': Integer(90300, None, 0, 60, 's'),
+    'quote_all_identifiers': Bool(90300, None),
+    'random_page_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'recovery_init_sync_method': Enum(140000, None, ('fsync', 'syncfs')),
+    'remove_temp_files_after_crash': Bool(140000, None),
+    'replacement_sort_tuples': Integer(90600, 110000, 0, 2147483647, None),
+    'restart_after_crash': Bool(90300, None),
+    'row_security': Bool(90500, None),
+    'search_path': String(90300, None),
+    'seq_page_cost': Real(90300, None, 0, 1.79769e+308, None),
+    'session_preload_libraries': String(90400, None),
+    'session_replication_role': Enum(90300, None, ('origin', 'replica', 'local')),
+    'shared_buffers': Integer(90300, None, 16, 1073741823, '8kB'),
+    'shared_memory_type': Enum(120000, None, ('sysv', 'mmap')),
+    'shared_preload_libraries': String(90300, None),
+    'sql_inheritance': Bool(90300, 100000),
+    'ssl': Bool(90300, None),
+    'ssl_ca_file': String(90300, None),
+    'ssl_cert_file': String(90300, None),
+    'ssl_ciphers': String(90300, None),
+    'ssl_crl_dir': String(140000, None),
+    'ssl_crl_file': String(90300, None),
+    'ssl_dh_params_file': String(100000, None),
+    'ssl_ecdh_curve': String(90400, None),
+    'ssl_key_file': String(90300, None),
+    'ssl_max_protocol_version': Enum(120000, None, ('', 'tlsv1', 'tlsv1.1', 'tlsv1.2', 'tlsv1.3')),
+    'ssl_min_protocol_version': Enum(120000, None, ('tlsv1', 'tlsv1.1', 'tlsv1.2', 'tlsv1.3')),
+    'ssl_passphrase_command': String(110000, None),
+    'ssl_passphrase_command_supports_reload': Bool(110000, None),
+    'ssl_prefer_server_ciphers': Bool(90400, None),
+    'ssl_renegotiation_limit': Integer(90300, 90500, 0, 2147483647, 'kB'),
+    'standard_conforming_strings': Bool(90300, None),
+    'statement_timeout': Integer(90300, None, 0, 2147483647, 'ms'),
+    'stats_temp_directory': String(90300, None),
+    'superuser_reserved_connections': (
+        Integer(90300, 90600, 0, 8388607, None),
+        Integer(90600, None, 0, 262143, None)
+    ),
+    'synchronize_seqscans': Bool(90300, None),
+    'synchronous_commit': (
+        EnumBool(90300, 90600, ('local', 'remote_write')),
+        EnumBool(90600, None, ('local', 'remote_write', 'remote_apply'))
+    ),
+    'synchronous_standby_names': String(90300, None),
+    'syslog_facility': Enum(90300, None, ('local0', 'local1', 'local2', 'local3',
+                                          'local4', 'local5', 'local6', 'local7')),
+    'syslog_ident': String(90300, None),
+    'syslog_sequence_numbers': Bool(90600, None),
+    'syslog_split_messages': Bool(90600, None),
+    'tcp_keepalives_count': Integer(90300, None, 0, 2147483647, None),
+    'tcp_keepalives_idle': Integer(90300, None, 0, 2147483647, 's'),
+    'tcp_keepalives_interval': Integer(90300, None, 0, 2147483647, 's'),
+    'tcp_user_timeout': Integer(120000, None, 0, 2147483647, 'ms'),
+    'temp_buffers': Integer(90300, None, 100, 1073741823, '8kB'),
+    'temp_file_limit': Integer(90300, None, -1, 2147483647, 'kB'),
+    'temp_tablespaces': String(90300, None),
+    'TimeZone': String(90300, None),
+    'timezone_abbreviations': String(90300, None),
+    'trace_notify': Bool(90300, None),
+    'trace_recovery_messages': Enum(90300, None, ('debug5', 'debug4', 'debug3', 'debug2',
+                                                  'debug1', 'log', 'notice', 'warning', 'error')),
+    'trace_sort': Bool(90300, None),
+    'track_activities': Bool(90300, None),
+    'track_activity_query_size': (
+        Integer(90300, 110000, 100, 102400, None),
+        Integer(110000, 130000, 100, 102400, 'B'),
+        Integer(130000, None, 100, 1048576, 'B')
+    ),
+    'track_commit_timestamp': Bool(90500, None),
+    'track_counts': Bool(90300, None),
+    'track_functions': Enum(90300, None, ('none', 'pl', 'all')),
+    'track_io_timing': Bool(90300, None),
+    'track_wal_io_timing': Bool(140000, None),
+    'transaction_deferrable': Bool(90300, None),
+    'transaction_isolation': Enum(90300, None, ('serializable', 'repeatable read',
+                                                'read committed', 'read uncommitted')),
+    'transaction_read_only': Bool(90300, None),
+    'transform_null_equals': Bool(90300, None),
+    'unix_socket_directories': String(90300, None),
+    'unix_socket_group': String(90300, None),
+    'unix_socket_permissions': Integer(90300, None, 0, 511, None),
+    'update_process_title': Bool(90300, None),
+    'vacuum_cleanup_index_scale_factor': Real(110000, 140000, 0, 1e+10, None),
+    'vacuum_cost_delay': (
+        Integer(90300, 120000, 0, 100, 'ms'),
+        Real(120000, None, 0, 100, 'ms')
+    ),
+    'vacuum_cost_limit': Integer(90300, None, 1, 10000, None),
+    'vacuum_cost_page_dirty': Integer(90300, None, 0, 10000, None),
+    'vacuum_cost_page_hit': Integer(90300, None, 0, 10000, None),
+    'vacuum_cost_page_miss': Integer(90300, None, 0, 10000, None),
+    'vacuum_defer_cleanup_age': Integer(90300, None, 0, 1000000, None),
+    'vacuum_failsafe_age': Integer(140000, None, '0', '2100000000', None),
+    'vacuum_freeze_min_age': Integer(90300, None, 0, 1000000000, None),
+    'vacuum_freeze_table_age': Integer(90300, None, 0, 2000000000, None),
+    'vacuum_multixact_failsafe_age': Integer(140000, None, '0', '2100000000', None),
+    'vacuum_multixact_freeze_min_age': Integer(90300, None, 0, 1000000000, None),
+    'vacuum_multixact_freeze_table_age': Integer(90300, None, 0, 2000000000, None),
+    'wal_buffers': Integer(90300, None, -1, 262143, '8kB'),
+    'wal_compression': Bool(90500, None),
+    'wal_consistency_checking': String(100000, None),
+    'wal_init_zero': Bool(120000, None),
+    'wal_keep_segments': Integer(90300, 130000, 0, 2147483647, None),
+    'wal_keep_size': Integer(130000, None, 0, 2147483647, 'MB'),
+    'wal_level': (
+        Enum(90300, 90400, ('minimal', 'archive', 'hot_standby')),
+        Enum(90400, 90600, ('minimal', 'archive', 'hot_standby', 'logical')),
+        Enum(90600, None, ('minimal', 'replica', 'logical'))
+    ),
+    'wal_log_hints': Bool(90400, None),
+    'wal_receiver_create_temp_slot': Bool(130000, None),
+    'wal_receiver_status_interval': Integer(90300, None, 0, 2147483, 's'),
+    'wal_receiver_timeout': Integer(90300, None, 0, 2147483647, 'ms'),
+    'wal_recycle': Bool(120000, None),
+    'wal_retrieve_retry_interval': Integer(90500, None, 1, 2147483647, 'ms'),
+    'wal_sender_timeout': Integer(90300, None, 0, 2147483647, 'ms'),
+    'wal_skip_threshold': Integer(130000, None, 0, 2147483647, 'kB'),
+    'wal_sync_method': Enum(90300, None, ('fsync', 'fdatasync', 'open_sync', 'open_datasync')),
+    'wal_writer_delay': Integer(90300, None, 1, 10000, 'ms'),
+    'wal_writer_flush_after': Integer(90600, None, 0, 2147483647, '8kB'),
+    'work_mem': Integer(90300, None, 64, 2147483647, 'kB'),
+    'xmlbinary': Enum(90300, None, ('base64', 'hex')),
+    'xmloption': Enum(90300, None, ('content', 'document')),
+    'zero_damaged_pages': Bool(90300, None)
+})
+
+
+recovery_parameters = CaseInsensitiveDict({
+    'archive_cleanup_command': String(90300, None),
+    'pause_at_recovery_target': Bool(90300, 90500),
+    'primary_conninfo': String(90300, None),
+    'primary_slot_name': String(90400, None),
+    'promote_trigger_file': String(120000, None),
+    'recovery_end_command': String(90300, None),
+    'recovery_min_apply_delay': Integer(90400, None, 0, 2147483647, 'ms'),
+    'recovery_target': Enum(90400, None, ('immediate', '')),
+    'recovery_target_action': Enum(90500, None, ('pause', 'promote', 'shutdown')),
+    'recovery_target_inclusive': Bool(90300, None),
+    'recovery_target_lsn': String(100000, None),
+    'recovery_target_name': String(90400, None),
+    'recovery_target_time': String(90300, None),
+    'recovery_target_timeline': String(90300, None),
+    'recovery_target_xid': String(90300, None),
+    'restore_command': String(90300, None),
+    'standby_mode': Bool(90300, 120000),
+    'trigger_file': String(90300, 120000)
+})
+
+
+def _transform_parameter_value(validators, version, name, value):
+    validators = validators.get(name)
+    if validators:
+        for validator in (validators if isinstance(validators[0], tuple) else [validators]):
+            if version >= validator.version_from and\
+                    (validator.version_till is None or version < validator.version_till):
+                return validator.transform(name, value)
+    logger.warning('Removing unexpected parameter=%s value=%s from the config', name, value)
+
+
+def transform_postgresql_parameter_value(version, name, value):
+    if '.' in name:
+        return value
+    if name in recovery_parameters:
+        return None
+    return _transform_parameter_value(parameters, version, name, value)
+
+
+def transform_recovery_parameter_value(version, name, value):
+    return _transform_parameter_value(recovery_parameters, version, name, value)

patroni/psycopg.py

@@ -0,0 +1,43 @@
+__all__ = ['connect', 'quote_ident', 'quote_literal', 'DatabaseError',
+           'Error', 'OperationalError', 'ProgrammingError', 'UndefinedFile']
+
+_legacy = False
+try:
+    from psycopg2 import __version__
+    from . import MIN_PSYCOPG2, parse_version
+    if parse_version(__version__) < MIN_PSYCOPG2:
+        raise ImportError
+    from psycopg2 import connect, Error, DatabaseError, OperationalError, ProgrammingError
+    from psycopg2.errors import UndefinedFile
+    from psycopg2.extensions import adapt
+
+    try:
+        from psycopg2.extensions import quote_ident as _quote_ident
+    except ImportError:
+        _legacy = True
+
+    def quote_literal(value, conn=None):
+        value = adapt(value)
+        if conn:
+            value.prepare(conn)
+        return value.getquoted().decode('utf-8')
+except ImportError:
+    from psycopg import connect as _connect, sql, Error, DatabaseError, OperationalError, ProgrammingError
+    from psycopg.errors import UndefinedFile
+
+    def connect(*args, **kwargs):
+        ret = _connect(*args, **kwargs)
+        ret.server_version = ret.pgconn.server_version  # compatibility with psycopg2
+        return ret
+
+    def _quote_ident(value, conn):
+        return sql.Identifier(value).as_string(conn)
+
+    def quote_literal(value, conn=None):
+        return sql.Literal(value).as_string(conn)
+
+
+def quote_ident(value, conn=None):
+    if _legacy or conn is None:
+        return '"{0}"'.format(value.replace('"', '""'))
+    return _quote_ident(value, conn)

patroni/raft_controller.py

@@ -0,0 +1,29 @@
+import logging
+
+from .daemon import AbstractPatroniDaemon, abstract_main
+from .dcs.raft import KVStoreTTL
+
+logger = logging.getLogger(__name__)
+
+
+class RaftController(AbstractPatroniDaemon):
+
+    def __init__(self, config):
+        super(RaftController, self).__init__(config)
+
+        config = self.config.get('raft')
+        assert 'self_addr' in config
+        self._raft = KVStoreTTL(None, None, None, **config)
+
+    def _run_cycle(self):
+        try:
+            self._raft.doTick(self._raft.conf.autoTickPeriod)
+        except Exception:
+            logger.exception('doTick')
+
+    def _shutdown(self):
+        self._raft.destroy()
+
+
+def main():
+    abstract_main(RaftController)

patroni/scripts/wale_restore.py

@@ -27,13 +27,14 @@ import argparse
 import csv
 import logging
 import os
-import psycopg2
 import subprocess
 import sys
 import time
 
 from collections import namedtuple
 
+from .. import psycopg
+
 logger = logging.getLogger(__name__)
 
 RETRY_SLEEP_INTERVAL = 1
@@ -215,7 +216,7 @@ class WALERestore(object):
             if self.master_connection:
                 try:
                     # get the difference in bytes between the current WAL location and the backup start offset
-                    with psycopg2.connect(self.master_connection) as con:
+                    with psycopg.connect(self.master_connection) as con:
                         if con.server_version >= 100000:
                             wal_name = 'wal'
                             lsn_name = 'lsn'
@@ -233,7 +234,7 @@ class WALERestore(object):
                                         (backup_start_lsn, backup_start_lsn, backup_start_lsn))
 
                             diff_in_bytes = int(cur.fetchone()[0])
-                except psycopg2.Error:
+                except psycopg.Error:
                     logger.exception('could not determine difference with the master location')
                     if attempts_no < self.retries:  # retry in case of a temporarily connection issue
                         attempts_no = attempts_no + 1
@@ -250,7 +251,7 @@ class WALERestore(object):
                 diff_in_bytes = 0
             break
 
-        # if the size of the accumulated WAL segments is more than a certan percentage of the backup size
+        # if the size of the accumulated WAL segments is more than a certain percentage of the backup size
         # or exceeds the pre-determined size - pg_basebackup is chosen instead.
         is_size_thresh_ok = diff_in_bytes < int(threshold_megabytes) * 1048576
         threshold_pct_bytes = backup_size * threshold_percent / 100.0
@@ -308,7 +309,7 @@ class WALERestore(object):
             try:
                 os.mkdir(path)
             except OSError:
-                logger.exception("coud not create missing %s directory path", dirname)
+                logger.exception("could not create missing %s directory path", dirname)
                 return False
         return True
 

patroni/utils.py

@@ -1,8 +1,12 @@
+import errno
+import json.decoder as json_decoder
 import logging
 import os
 import platform
 import random
 import re
+import socket
+import sys
 import tempfile
 import time
 
@@ -357,6 +361,8 @@ def polling_loop(timeout, interval=1):
 
 def split_host_port(value, default_port):
     t = value.rsplit(':', 1)
+    if ':' in t[0]:
+        t[0] = t[0].strip('[]')
     t.append(default_port)
     return t[0], int(t[1])
 
@@ -371,6 +377,27 @@ def uri(proto, netloc, path='', user=None):
     return '{0}://{1}{2}{3}{4}'.format(proto, user, host, port, path)
 
 
+def iter_response_objects(response):
+    prev = ''
+    decoder = json_decoder.JSONDecoder()
+    for chunk in response.read_chunked(decode_content=False):
+        if isinstance(chunk, bytes):
+            chunk = chunk.decode('utf-8')
+        chunk = prev + chunk
+
+        length = len(chunk)
+        idx = json_decoder.WHITESPACE.match(chunk, 0).end()
+        while idx < length:
+            try:
+                message, idx = decoder.raw_decode(chunk, idx)
+            except ValueError:  # malformed or incomplete JSON, unlikely to happen
+                break
+            else:
+                yield message
+                idx = json_decoder.WHITESPACE.match(chunk, idx).end()
+        prev = chunk[idx:]
+
+
 def is_standby_cluster(config):
     # Check whether or not provided configuration describes a standby cluster
     return isinstance(config, dict) and (config.get('host') or config.get('port') or config.get('restore_command'))
@@ -378,14 +405,14 @@ def is_standby_cluster(config):
 
 def cluster_as_json(cluster):
     leader_name = cluster.leader.name if cluster.leader else None
-    xlog_location_cluster = cluster.last_leader_operation or 0
+    cluster_lsn = cluster.last_lsn or 0
 
     ret = {'members': []}
     for m in cluster.members:
         if m.name == leader_name:
             config = cluster.config.data if cluster.config and cluster.config.modify_index else {}
             role = 'standby_leader' if is_standby_cluster(config.get('standby_cluster')) else 'leader'
-        elif m.name == cluster.sync.sync_standby:
+        elif m.name in cluster.sync.members:
             role = 'sync_standby'
         else:
             role = 'replica'
@@ -400,11 +427,11 @@ def cluster_as_json(cluster):
         member.update({n: m.data[n] for n in optional_attributes if n in m.data})
 
         if m.name != leader_name:
-            xlog_location = m.data.get('xlog_location')
-            if xlog_location is None:
+            lsn = m.data.get('xlog_location')
+            if lsn is None:
                 member['lag'] = 'unknown'
-            elif xlog_location_cluster >= xlog_location:
-                member['lag'] = xlog_location_cluster - xlog_location
+            elif cluster_lsn >= lsn:
+                member['lag'] = cluster_lsn - lsn
             else:
                 member['lag'] = 0
 
@@ -435,7 +462,8 @@ def validate_directory(d, msg="{} {}"):
             os.makedirs(d)
         except OSError as e:
             logger.error(e)
-            raise PatroniException(msg.format(d, "couldn't create the directory"))
+            if e.errno != errno.EEXIST:
+                raise PatroniException(msg.format(d, "couldn't create the directory"))
     elif os.path.isdir(d):
         try:
             fd, tmpfile = tempfile.mkstemp(dir=d)
@@ -451,3 +479,56 @@ def data_directory_is_empty(data_dir):
     if not os.path.exists(data_dir):
         return True
     return all(os.name != 'nt' and (n.startswith('.') or n == 'lost+found') for n in os.listdir(data_dir))
+
+
+def keepalive_intvl(timeout, idle, cnt=3):
+    return max(1, int(float(timeout - idle) / cnt))
+
+
+def keepalive_socket_options(timeout, idle, cnt=3):
+    yield (socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
+
+    if sys.platform.startswith('linux'):
+        yield (socket.SOL_TCP, 18, int(timeout * 1000))  # TCP_USER_TIMEOUT
+        TCP_KEEPIDLE = getattr(socket, 'TCP_KEEPIDLE', None)
+        TCP_KEEPINTVL = getattr(socket, 'TCP_KEEPINTVL', None)
+        TCP_KEEPCNT = getattr(socket, 'TCP_KEEPCNT', None)
+    elif sys.platform.startswith('darwin'):
+        TCP_KEEPIDLE = 0x10  # (named "TCP_KEEPALIVE" in C)
+        TCP_KEEPINTVL = 0x101
+        TCP_KEEPCNT = 0x102
+    else:
+        return
+
+    intvl = keepalive_intvl(timeout, idle, cnt)
+    yield (socket.IPPROTO_TCP, TCP_KEEPIDLE, idle)
+    yield (socket.IPPROTO_TCP, TCP_KEEPINTVL, intvl)
+    yield (socket.IPPROTO_TCP, TCP_KEEPCNT, cnt)
+
+
+def enable_keepalive(sock, timeout, idle, cnt=3):
+    SIO_KEEPALIVE_VALS = getattr(socket, 'SIO_KEEPALIVE_VALS', None)
+    if SIO_KEEPALIVE_VALS is not None:  # Windows
+        intvl = keepalive_intvl(timeout, idle, cnt)
+        return sock.ioctl(SIO_KEEPALIVE_VALS, (1, idle * 1000, intvl * 1000))
+
+    for opt in keepalive_socket_options(timeout, idle, cnt):
+        sock.setsockopt(*opt)
+
+
+def find_executable(executable, path=None):
+    _, ext = os.path.splitext(executable)
+
+    if (sys.platform == 'win32') and (ext != '.exe'):
+        executable = executable + '.exe'
+
+    if os.path.isfile(executable):
+        return executable
+
+    if path is None:
+        path = os.environ.get('PATH', os.defpath)
+
+    for p in path.split(os.pathsep):
+        f = os.path.join(p, executable)
+        if os.path.isfile(f):
+            return f

patroni/validator.py

@@ -4,12 +4,12 @@ import socket
 import re
 import subprocess
 
-from patroni.utils import split_host_port, data_directory_is_empty
-from patroni.ctl import find_executable
-from patroni.dcs import dcs_modules
-from patroni.exceptions import ConfigParseError
 from six import string_types
 
+from .utils import find_executable, split_host_port, data_directory_is_empty
+from .dcs import dcs_modules
+from .exceptions import ConfigParseError
+
 
 def data_directory_empty(data_dir):
     if os.path.isfile(os.path.join(data_dir, "global", "pg_control")):
@@ -53,11 +53,15 @@ def validate_host_port(host_port, listen=False, multiple_hosts=False):
     return True
 
 
-def comma_separated_host_port(string):
-    assert all([validate_host_port(s.strip()) for s in string.split(",")]), "didn't pass the validation"
+def validate_host_port_list(value):
+    assert all([validate_host_port(v) for v in value]), "didn't pass the validation"
     return True
 
 
+def comma_separated_host_port(string):
+    return validate_host_port_list([s.strip() for s in string.split(",")])
+
+
 def validate_host_port_listen(host_port):
     return validate_host_port(host_port, listen=True)
 
@@ -291,11 +295,21 @@ def assert_(condition, message="Wrong value"):
 
 userattributes = {"username": "", Optional("password"): ""}
 available_dcs = [m.split(".")[-1] for m in dcs_modules()]
+validate_host_port_list.expected_type = list
 comma_separated_host_port.expected_type = string_types
 validate_connect_address.expected_type = string_types
 validate_host_port_listen.expected_type = string_types
 validate_host_port_listen_multiple_hosts.expected_type = string_types
 validate_data_dir.expected_type = string_types
+validate_etcd = {
+    Or("host", "hosts", "srv", "srv_suffix", "url", "proxy"): Case({
+        "host": validate_host_port,
+        "hosts": Or(comma_separated_host_port, [validate_host_port]),
+        "srv": str,
+        "srv_suffix": str,
+        "url": str,
+        "proxy": str})
+}
 
 schema = Schema({
   "name": str,
@@ -320,19 +334,20 @@ schema = Schema({
               "host": validate_host_port,
               "url": str})
           },
-      "etcd": {
-          Or("host", "hosts", "srv", "url", "proxy"): Case({
-              "host": validate_host_port,
-              "hosts": Or(comma_separated_host_port, [validate_host_port]),
-              "srv": str,
-              "url": str,
-              "proxy": str})
-         },
+      "etcd": validate_etcd,
+      "etcd3": validate_etcd,
       "exhibitor": {
           "hosts": [str],
           "port": lambda i: assert_(int(i) <= 65535),
           Optional("pool_interval"): int
           },
+      "raft": {
+          "self_addr": validate_connect_address,
+          Optional("bind_addr"): validate_host_port_listen,
+          "partner_addrs": validate_host_port_list,
+          Optional("data_dir"): str,
+          Optional("password"): str
+          },
       "zookeeper": {
           "hosts": Or(comma_separated_host_port, [validate_host_port]),
           },

patroni/version.py

@@ -1 +1 @@
-__version__ = '1.6.5'
+__version__ = '2.1.2'

patroni_raft_controller.py

@@ -0,0 +1,6 @@
+#!/usr/bin/env python
+from patroni.raft_controller import main
+
+
+if __name__ == '__main__':
+    main()

postgres0.yml

@@ -30,6 +30,13 @@ etcd:
   #It is possible to change this behavior through by setting:
   #use_proxies: true
 
+#raft:
+#  data_dir: .
+#  self_addr: 127.0.0.1:2222
+#  partner_addrs:
+#  - 127.0.0.1:2223
+#  - 127.0.0.1:2224
+
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
   # and all other cluster members will use it as a `global configuration`
@@ -50,10 +57,15 @@ bootstrap:
       parameters:
 #        wal_level: hot_standby
 #        hot_standby: "on"
+#        max_connections: 100
+#        max_worker_processes: 8
 #        wal_keep_segments: 8
 #        max_wal_senders: 10
 #        max_replication_slots: 10
+#        max_prepared_transactions: 0
+#        max_locks_per_transaction: 64
 #        wal_log_hints: "on"
+#        track_commit_timestamp: "off"
 #        archive_mode: "on"
 #        archive_timeout: 1800s
 #        archive_command: mkdir -p ../wal_archive && test ! -f ../wal_archive/%f && cp %p ../wal_archive/%f
@@ -108,6 +120,8 @@ postgresql:
     # same as KRB5CCNAME used by the GSS
 #   krb_server_keyfile: /var/spool/keytabs/postgres
     unix_socket_directories: '.'
+  # Additional fencing script executed after acquiring the leader lock but before promoting the replica
+  #pre_promote: /path/to/pre_promote.sh
 
 #watchdog:
 #  mode: automatic # Allowed values: off, automatic, required

postgres1.yml

@@ -30,6 +30,13 @@ etcd:
   #It is possible to change this behavior through by setting:
   #use_proxies: true
 
+#raft:
+#  data_dir: .
+#  self_addr: 127.0.0.1:2223
+#  partner_addrs:
+#  - 127.0.0.1:2222
+#  - 127.0.0.1:2224
+
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
   # and all other cluster members will use it as a `global configuration`
@@ -44,10 +51,15 @@ bootstrap:
       parameters:
 #        wal_level: hot_standby
 #        hot_standby: "on"
+#        max_connections: 100
+#        max_worker_processes: 8
 #        wal_keep_segments: 8
 #        max_wal_senders: 10
 #        max_replication_slots: 10
+#        max_prepared_transactions: 0
+#        max_locks_per_transaction: 64
 #        wal_log_hints: "on"
+#        track_commit_timestamp: "off"
 #        archive_mode: "on"
 #        archive_timeout: 1800s
 #        archive_command: mkdir -p ../wal_archive && test ! -f ../wal_archive/%f && cp %p ../wal_archive/%f
@@ -105,6 +117,10 @@ postgresql:
   basebackup:
       - verbose
       - max-rate: 100M
+#      - waldir: /pg-wal-mount/external-waldir # only needed in case pg_wal is symlinked outside of data_dir
+  # Additional fencing script executed after acquiring the leader lock but before promoting the replica
+  #pre_promote: /path/to/pre_promote.sh
+
 tags:
     nofailover: false
     noloadbalance: false

postgres2.yml

@@ -30,6 +30,13 @@ etcd:
   #It is possible to change this behavior through by setting:
   #use_proxies: true
 
+#raft:
+#  data_dir: .
+#  self_addr: 127.0.0.1:2224
+#  partner_addrs:
+#  - 127.0.0.1:2222
+#  - 127.0.0.1:2223
+
 bootstrap:
   # this section will be written into Etcd:/<namespace>/<scope>/config after initializing new cluster
   # and all other cluster members will use it as a `global configuration`
@@ -44,10 +51,15 @@ bootstrap:
       parameters:
 #        wal_level: hot_standby
 #        hot_standby: "on"
+#        max_connections: 100
+#        max_worker_processes: 8
 #        wal_keep_segments: 8
 #        max_wal_senders: 10
 #        max_replication_slots: 10
+#        max_prepared_transactions: 0
+#        max_locks_per_transaction: 64
 #        wal_log_hints: "on"
+#        track_commit_timestamp: "off"
 #        archive_mode: "on"
 #        archive_timeout: 1800s
 #        archive_command: mkdir -p ../wal_archive && test ! -f ../wal_archive/%f && cp %p ../wal_archive/%f

requirements.dev.txt

@@ -0,0 +1,8 @@
+psycopg2-binary
+behave
+coverage
+flake8
+mock
+pytest-cov
+pytest
+setuptools

requirements.txt

@@ -1,4 +1,5 @@
 urllib3>=1.19.1,!=1.21
+ipaddress; python_version=="2.7"
 boto
 PyYAML
 six >= 1.7
@@ -8,6 +9,7 @@ python-consul>=0.7.1
 click>=4.1
 prettytable>=0.7
 python-dateutil
+pysyncobj>=0.3.8
+cryptography>=1.4
 psutil>=2.0.0
-cdiff
-kubernetes>=2.0.0,<=10.0.1,!=4.0.*,!=5.0.*
+ydiff>=1.2.0

setup.py

@@ -22,8 +22,9 @@ AUTHOR_EMAIL = '[email protected], [email protected], alexk
 KEYWORDS = 'etcd governor patroni postgresql postgres ha haproxy confd' +\
     ' zookeeper exhibitor consul streaming replication kubernetes k8s'
 
-EXTRAS_REQUIRE = {'aws': ['boto'], 'etcd': ['python-etcd'], 'consul': ['python-consul'],
-                  'exhibitor': ['kazoo'], 'zookeeper': ['kazoo'], 'kubernetes': ['kubernetes']}
+EXTRAS_REQUIRE = {'aws': ['boto'], 'etcd': ['python-etcd'], 'etcd3': ['python-etcd'],
+                  'consul': ['python-consul'], 'exhibitor': ['kazoo'], 'zookeeper': ['kazoo'],
+                  'kubernetes': [], 'raft': ['pysyncobj', 'cryptography']}
 COVERAGE_XML = True
 COVERAGE_HTML = False
 
@@ -46,15 +47,67 @@ CLASSIFIERS = [
     'Programming Language :: Python :: 3.5',
     'Programming Language :: Python :: 3.6',
     'Programming Language :: Python :: 3.7',
+    'Programming Language :: Python :: 3.8',
+    'Programming Language :: Python :: 3.9',
     'Programming Language :: Python :: Implementation :: CPython',
 ]
 
 CONSOLE_SCRIPTS = ['patroni = patroni:main',
                    'patronictl = patroni.ctl:ctl',
+                   'patroni_raft_controller = patroni.raft_controller:main',
                    "patroni_wale_restore = patroni.scripts.wale_restore:main",
                    "patroni_aws = patroni.scripts.aws:main"]
 
 
+class Flake8(Command):
+
+    user_options = []
+
+    def initialize_options(self):
+        from flake8.main import application
+
+        self.flake8 = application.Application()
+        self.flake8.initialize([])
+
+    def finalize_options(self):
+        pass
+
+    def package_files(self):
+        seen_package_directories = ()
+        directories = self.distribution.package_dir or {}
+        empty_directory_exists = "" in directories
+        packages = self.distribution.packages or []
+        for package in packages:
+            if package in directories:
+                package_directory = directories[package]
+            elif empty_directory_exists:
+                package_directory = os.path.join(directories[""], package)
+            else:
+                package_directory = package
+
+            if not package_directory.startswith(seen_package_directories):
+                seen_package_directories += (package_directory + ".",)
+                yield package_directory
+
+    def targets(self):
+        return [package for package in self.package_files()] + ['tests', 'setup.py']
+
+    def run(self):
+        self.flake8.run_checks(self.targets())
+        self.flake8.formatter.start()
+        self.flake8.report_errors()
+        self.flake8.report_statistics()
+        self.flake8.report_benchmarks()
+        self.flake8.formatter.stop()
+        try:
+            self.flake8.exit()
+        except SystemExit as e:
+            # Cause system exit only if exit code is not zero (terminates
+            # other possibly remaining/pending setuptools commands).
+            if e.code:
+                raise
+
+
 class PyTest(Command):
 
     user_options = [('cov=', None, 'Run coverage'), ('cov-xml=', None, 'Generate junit xml report'),
@@ -93,9 +146,13 @@ class PyTest(Command):
 
     def run(self):
         from pkg_resources import evaluate_marker
-        requirements = self.distribution.install_requires + ['mock>=2.0.0', 'pytest-cov', 'pytest'] +\
-            [v for k, v in self.distribution.extras_require.items() if not k.startswith(':') or evaluate_marker(k[1:])]
-        self.distribution.fetch_build_eggs(requirements)
+
+        requirements = set(self.distribution.install_requires + ['mock>=2.0.0', 'pytest-cov', 'pytest'])
+        for k, v in self.distribution.extras_require.items():
+            if not k.startswith(':') or evaluate_marker(k[1:]):
+                requirements.update(v)
+
+        self.distribution.fetch_build_eggs(list(requirements))
         self.run_tests()
 
 
@@ -106,7 +163,7 @@ def read(fname):
 
 def setup_package(version):
     # Assemble additional setup commands
-    cmdclass = {'test': PyTest}
+    cmdclass = {'test': PyTest, 'flake8': Flake8}
 
     install_requires = []
 
@@ -115,10 +172,15 @@ def setup_package(version):
         if r == '':
             continue
         extra = False
-        for e, v in EXTRAS_REQUIRE.items():
-            if r.startswith(v[0]):
-                EXTRAS_REQUIRE[e] = [r]
-                extra = True
+        for e, deps in EXTRAS_REQUIRE.items():
+            for i, v in enumerate(deps):
+                if r.startswith(v):
+                    deps[i] = r
+                    EXTRAS_REQUIRE[e] = deps
+                    extra = True
+                    break
+            if extra:
+                break
         if not extra:
             install_requires.append(r)
 
@@ -154,13 +216,13 @@ def setup_package(version):
 if __name__ == '__main__':
     old_modules = sys.modules.copy()
     try:
-        from patroni import check_psycopg2, fatal, __version__
+        from patroni import check_psycopg, fatal, __version__
     finally:
         sys.modules.clear()
         sys.modules.update(old_modules)
 
     if sys.version_info < (2, 7, 0):
         fatal('Patroni needs to be run with Python 2.7+')
-    check_psycopg2()
+    check_psycopg()
 
     setup_package(__version__)

tests/__init__.py

@@ -5,13 +5,14 @@ import unittest
 
 from mock import Mock, patch
 
-import psycopg2
 import urllib3
 
+import patroni.psycopg as psycopg
+
 from patroni.dcs import Leader, Member
 from patroni.postgresql import Postgresql
 from patroni.postgresql.config import ConfigHandler
-from patroni.utils import RetryFailedError
+from patroni.utils import RetryFailedError, tzutc
 
 
 class SleepException(Exception):
@@ -23,6 +24,7 @@ class MockResponse(object):
     def __init__(self, status_code=200):
         self.status_code = status_code
         self.content = '{}'
+        self.reason = 'Not Found'
 
     @property
     def data(self):
@@ -36,6 +38,10 @@ class MockResponse(object):
     def getheader(*args):
         return ''
 
+    @staticmethod
+    def getheaders():
+        return {'content-type': 'json'}
+
 
 def requests_get(url, **kwargs):
     members = '[{"id":14855829450254237642,"peerURLs":["http://localhost:2380","http://localhost:7001"],' +\
@@ -80,21 +86,26 @@ class MockCursor(object):
 
     def execute(self, sql, *params):
         if sql.startswith('blabla'):
-            raise psycopg2.ProgrammingError()
+            raise psycopg.ProgrammingError()
         elif sql == 'CHECKPOINT' or sql.startswith('SELECT pg_catalog.pg_create_'):
-            raise psycopg2.OperationalError()
+            raise psycopg.OperationalError()
         elif sql.startswith('RetryFailedError'):
             raise RetryFailedError('retry')
+        elif sql.startswith('SELECT catalog_xmin'):
+            self.results = [(100, 501)]
+        elif sql.startswith('SELECT slot_name, catalog_xmin'):
+            self.results = [('ls', 100, 500, b'123456')]
         elif sql.startswith('SELECT slot_name'):
-            self.results = [('blabla', 'physical'), ('foobar', 'physical'), ('ls', 'logical', 'a', 'b')]
+            self.results = [('blabla', 'physical'), ('foobar', 'physical'), ('ls', 'logical', 'a', 'b', 5, 100, 500)]
         elif sql.startswith('SELECT CASE WHEN pg_catalog.pg_is_in_recovery()'):
-            self.results = [(1, 2, 1)]
+            self.results = [(1, 2, 1, 0, False, 1, 1, None, None, [{"slot_name": "ls", "confirmed_flush_lsn": 12345}])]
         elif sql.startswith('SELECT pg_catalog.pg_is_in_recovery()'):
             self.results = [(False, 2)]
-        elif sql.startswith('SELECT pg_catalog.to_char'):
+        elif sql.startswith('SELECT pg_catalog.pg_postmaster_start_time'):
             replication_info = '[{"application_name":"walreceiver","client_addr":"1.2.3.4",' +\
                                '"state":"streaming","sync_state":"async","sync_priority":0}]'
-            self.results = [('', 0, '', '', '', '', False, replication_info)]
+            now = datetime.datetime.now(tzutc)
+            self.results = [(now, 0, '', 0, '', False, now, replication_info)]
         elif sql.startswith('SELECT name, setting'):
             self.results = [('wal_segment_size', '2048', '8kB', 'integer', 'internal'),
                             ('wal_block_size', '8192', None, 'integer', 'internal'),
@@ -106,12 +117,7 @@ class MockCursor(object):
                             ('autovacuum', 'on', None, 'bool', 'sighup'),
                             ('unix_socket_directories', '/tmp', None, 'string', 'postmaster')]
         elif sql.startswith('IDENTIFY_SYSTEM'):
-            self.results = [('1', 2, '0/402EEC0', '')]
-        elif sql.startswith('SELECT isdir, modification'):
-            self.results = [(False, datetime.datetime.now())]
-        elif sql.startswith('SELECT pg_catalog.pg_read_file'):
-            self.results = [('1\t0/40159C0\tno recovery target specified\n\n'
-                             '2\t1/40159C0\tno recovery target specified\n',)]
+            self.results = [('1', 3, '0/402EEC0', '')]
         elif sql.startswith('TIMELINE_HISTORY '):
             self.results = [('', b'x\t0/40159C0\tno recovery target specified\n\n'
                                  b'1\t0/40159C0\tno recovery target specified\n\n'
@@ -157,7 +163,7 @@ class MockConnect(object):
         pass
 
 
-def psycopg2_connect(*args, **kwargs):
+def psycopg_connect(*args, **kwargs):
     return MockConnect()
 
 
@@ -166,10 +172,13 @@ class PostgresInit(unittest.TestCase):
                    'search_path': 'public', 'hot_standby': 'on', 'max_wal_senders': 5,
                    'wal_keep_segments': 8, 'wal_log_hints': 'on', 'max_locks_per_transaction': 64,
                    'max_worker_processes': 8, 'max_connections': 100, 'max_prepared_transactions': 0,
-                   'track_commit_timestamp': 'off', 'unix_socket_directories': '/tmp', 'trigger_file': 'bla',
-                   'stats_temp_directory': '/tmp'}
+                   'track_commit_timestamp': 'off', 'unix_socket_directories': '/tmp',
+                   'trigger_file': 'bla', 'stats_temp_directory': '/tmp', 'zero_damaged_pages': '',
+                   'force_parallel_mode': '1', 'constraint_exclusion': '',
+                   'max_stack_depth': 'Z', 'vacuum_cost_limit': -1, 'vacuum_cost_delay': 200}
 
-    @patch('psycopg2.connect', psycopg2_connect)
+    @patch('patroni.psycopg.connect', psycopg_connect)
+    @patch('patroni.postgresql.CallbackExecutor', Mock())
     @patch.object(ConfigHandler, 'write_postgresql_conf', Mock())
     @patch.object(ConfigHandler, 'replace_pg_hba', Mock())
     @patch.object(ConfigHandler, 'replace_pg_ident', Mock())

tests/test_api.py

@@ -1,9 +1,10 @@
 import datetime
 import json
-import psycopg2
 import unittest
 import socket
 
+import patroni.psycopg as psycopg
+
 from mock import Mock, PropertyMock, patch
 from patroni.api import RestApiHandler, RestApiServer
 from patroni.dcs import ClusterConfig, Member
@@ -11,7 +12,7 @@ from patroni.ha import _MemberStatus
 from patroni.utils import tzutc
 from six import BytesIO as IO
 from six.moves import BaseHTTPServer
-from . import psycopg2_connect, MockCursor
+from . import psycopg_connect, MockCursor
 from .test_ha import get_cluster_initialized_without_leader
 
 
@@ -30,14 +31,16 @@ class MockPostgresql(object):
     pending_restart = True
     wal_name = 'wal'
     lsn_name = 'lsn'
+    POSTMASTER_START_TIME = 'pg_catalog.pg_postmaster_start_time()'
+    TL_LSN = 'CASE WHEN pg_catalog.pg_is_in_recovery()'
 
     @staticmethod
     def connection():
-        return psycopg2_connect()
+        return psycopg_connect()
 
     @staticmethod
     def postmaster_start_time():
-        return str(postmaster_start_time)
+        return postmaster_start_time
 
     @staticmethod
     def replica_cached_timeline(_):
@@ -75,7 +78,7 @@ class MockHa(object):
 
     @staticmethod
     def fetch_nodes_statuses(members):
-        return [_MemberStatus(None, True, None, 0, None, {}, False)]
+        return [_MemberStatus(None, True, None, 0, 0, None, {}, False)]
 
     @staticmethod
     def schedule_future_restart(data):
@@ -116,7 +119,7 @@ class MockPatroni(object):
     postgresql = ha.state_handler
     dcs = Mock()
     logger = MockLogger()
-    tags = {}
+    tags = {"key1": True, "key2": False, "key3": 1, "key4": 1.4, "key5": "RandomTag"}
     version = '0.00'
     noloadbalance = PropertyMock(return_value=False)
     scheduled_restart = {'schedule': future_restart_time,
@@ -146,7 +149,8 @@ class MockRestApiServer(RestApiServer):
         self.serve_forever = Mock()
         MockRestApiServer._BaseServer__is_shut_down = Mock()
         MockRestApiServer._BaseServer__shutdown_request = True
-        config = config or {'listen': '127.0.0.1:8008', 'auth': 'test:test', 'certfile': 'dumb', 'verify_client': 'a'}
+        config = config or {'listen': '127.0.0.1:8008', 'auth': 'test:test', 'certfile': 'dumb', 'verify_client': 'a',
+                            'http_extra_headers': {'foo': 'bar'}, 'https_extra_headers': {'foo': 'sbar'}}
         super(MockRestApiServer, self).__init__(MockPatroni(), config)
         Handler(MockRequest(request), ('0.0.0.0', 8080), self)
 
@@ -159,7 +163,11 @@ class TestRestApiHandler(unittest.TestCase):
     _authorization = '\nAuthorization: Basic dGVzdDp0ZXN0'
 
     def test_do_GET(self):
+        MockPatroni.dcs.cluster.last_lsn = 20
         MockRestApiServer(RestApiHandler, 'GET /replica')
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M')
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=10MB')
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=10485760')
         MockRestApiServer(RestApiHandler, 'GET /read-only')
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={})):
             MockRestApiServer(RestApiHandler, 'GET /replica')
@@ -167,16 +175,18 @@ class TestRestApiHandler(unittest.TestCase):
             MockRestApiServer(RestApiHandler, 'GET /replica')
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'state': 'running'})):
             MockRestApiServer(RestApiHandler, 'GET /health')
-        MockRestApiServer(RestApiHandler, 'GET /master')
-        MockPatroni.dcs.cluster.sync.sync_standby = MockPostgresql.name
+        MockRestApiServer(RestApiHandler, 'GET /leader')
+        MockPatroni.dcs.cluster.sync.members = [MockPostgresql.name]
         MockPatroni.dcs.cluster.is_synchronous_mode = Mock(return_value=True)
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'replica'})):
             MockRestApiServer(RestApiHandler, 'GET /synchronous')
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'replica'})):
-            MockPatroni.dcs.cluster.sync.sync_standby = ''
+            MockPatroni.dcs.cluster.sync.members = []
             MockRestApiServer(RestApiHandler, 'GET /asynchronous')
-        MockPatroni.ha.is_leader = Mock(return_value=True)
-        MockRestApiServer(RestApiHandler, 'GET /replica')
+        with patch.object(MockHa, 'is_leader', Mock(return_value=True)):
+            MockRestApiServer(RestApiHandler, 'GET /replica')
+            with patch.object(MockHa, 'is_standby_cluster', Mock(return_value=True)):
+                MockRestApiServer(RestApiHandler, 'GET /standby_leader')
         MockPatroni.dcs.cluster = None
         with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'master'})):
             MockRestApiServer(RestApiHandler, 'GET /master')
@@ -188,9 +198,102 @@ class TestRestApiHandler(unittest.TestCase):
         with patch.object(MockHa, 'is_standby_cluster', Mock(return_value=True)):
             MockRestApiServer(RestApiHandler, 'GET /standby_leader')
 
+        # test tags
+        #
+        MockRestApiServer(RestApiHandler, 'GET /master?lag=1M&'
+                                          'tag_key1=true&tag_key2=false&'
+                                          'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+        MockRestApiServer(RestApiHandler, 'GET /master?lag=1M&'
+                                          'tag_key1=true&tag_key2=False&'
+                                          'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+        MockRestApiServer(RestApiHandler, 'GET /master?lag=1M&'
+                                          'tag_key1=true&tag_key2=false&'
+                                          'tag_key3=1.0&tag_key4=1.4&tag_key5=RandomTag')
+        MockRestApiServer(RestApiHandler, 'GET /master?lag=1M&'
+                                          'tag_key1=true&tag_key2=false&'
+                                          'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag&tag_key6=RandomTag2')
+        #
+        with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'master'})):
+            MockRestApiServer(RestApiHandler, 'GET /master?lag=1M&'
+                                              'tag_key1=true&tag_key2=false&'
+                                              'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+            MockRestApiServer(RestApiHandler, 'GET /master?lag=1M&'
+                                              'tag_key1=true&tag_key2=False&'
+                                              'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+            MockRestApiServer(RestApiHandler, 'GET /master?lag=1M&'
+                                              'tag_key1=true&tag_key2=false&'
+                                              'tag_key3=1.0&tag_key4=1.4&tag_key5=RandomTag')
+            MockRestApiServer(RestApiHandler, 'GET /master?lag=1M&'
+                                              'tag_key1=true&tag_key2=false&'
+                                              'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag&tag_key6=RandomTag2')
+        #
+        with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'standby_leader'})):
+            MockRestApiServer(RestApiHandler, 'GET /standby_leader?lag=1M&'
+                                              'tag_key1=true&tag_key2=false&'
+                                              'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+            MockRestApiServer(RestApiHandler, 'GET /standby_leader?lag=1M&'
+                                              'tag_key1=true&tag_key2=False&'
+                                              'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+            MockRestApiServer(RestApiHandler, 'GET /standby_leader?lag=1M&'
+                                              'tag_key1=true&tag_key2=false&'
+                                              'tag_key3=1.0&tag_key4=1.4&tag_key5=RandomTag')
+            MockRestApiServer(RestApiHandler, 'GET /standby_leader?lag=1M&'
+                                              'tag_key1=true&tag_key2=false&'
+                                              'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag&tag_key6=RandomTag2')
+        #
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M&'
+                                          'tag_key1=true&tag_key2=false&'
+                                          'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M&'
+                                          'tag_key1=true&tag_key2=False&'
+                                          'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M&'
+                                          'tag_key1=true&tag_key2=false&'
+                                          'tag_key3=1.0&tag_key4=1.4&tag_key5=RandomTag')
+        MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M&'
+                                          'tag_key1=true&tag_key2=false&'
+                                          'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag&tag_key6=RandomTag2')
+        #
+        with patch.object(RestApiHandler, 'get_postgresql_status', Mock(return_value={'role': 'master'})):
+            MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M&'
+                                              'tag_key1=true&tag_key2=false&'
+                                              'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+            MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M&'
+                                              'tag_key1=true&tag_key2=False&'
+                                              'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+            MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M&'
+                                              'tag_key1=true&tag_key2=false&'
+                                              'tag_key3=1.0&tag_key4=1.4&tag_key5=RandomTag')
+            MockRestApiServer(RestApiHandler, 'GET /replica?lag=1M&'
+                                              'tag_key1=true&tag_key2=false&'
+                                              'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag&tag_key6=RandomTag2')
+        #
+        MockRestApiServer(RestApiHandler, 'GET /read-write?lag=1M&'
+                                          'tag_key1=true&tag_key2=false&'
+                                          'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+        MockRestApiServer(RestApiHandler, 'GET /read-write?lag=1M&'
+                                          'tag_key1=true&tag_key2=False&'
+                                          'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag')
+        MockRestApiServer(RestApiHandler, 'GET /read-write?lag=1M&'
+                                          'tag_key1=true&tag_key2=false&'
+                                          'tag_key3=1.0&tag_key4=1.4&tag_key5=RandomTag')
+        MockRestApiServer(RestApiHandler, 'GET /read-write?lag=1M&'
+                                          'tag_key1=true&tag_key2=false&'
+                                          'tag_key3=1&tag_key4=1.4&tag_key5=RandomTag&tag_key6=RandomTag2')
+
     def test_do_OPTIONS(self):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'OPTIONS / HTTP/1.0'))
 
+    def test_do_GET_liveness(self):
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /liveness HTTP/1.0'))
+
+    def test_do_GET_readiness(self):
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /readiness HTTP/1.0'))
+        with patch.object(MockHa, 'is_leader', Mock(return_value=True)):
+            self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /readiness HTTP/1.0'))
+        with patch.object(MockPostgresql, 'state', PropertyMock(return_value='stopped')):
+            self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /readiness HTTP/1.0'))
+
     @patch.object(MockPostgresql, 'state', PropertyMock(return_value='stopped'))
     def test_do_GET_patroni(self):
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /patroni'))
@@ -201,8 +304,8 @@ class TestRestApiHandler(unittest.TestCase):
 
     @patch.object(MockPatroni, 'dcs')
     def test_do_GET_cluster(self, mock_dcs):
-        mock_dcs.cluster = get_cluster_initialized_without_leader()
-        mock_dcs.cluster.members[1].data['xlog_location'] = 11
+        mock_dcs.get_cluster.return_value = get_cluster_initialized_without_leader()
+        mock_dcs.get_cluster.return_value.members[1].data['xlog_location'] = 11
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /cluster'))
 
     @patch.object(MockPatroni, 'dcs')
@@ -217,6 +320,10 @@ class TestRestApiHandler(unittest.TestCase):
         mock_dcs.cluster.config = None
         self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /config'))
 
+    @patch.object(MockPatroni, 'dcs')
+    def test_do_GET_metrics(self, mock_dcs):
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /metrics'))
+
     @patch.object(MockPatroni, 'dcs')
     def test_do_PATCH_config(self, mock_dcs):
         config = {'postgresql': {'use_slots': False, 'use_pg_rewind': True, 'parameters': {'wal_level': 'logical'}}}
@@ -232,6 +339,8 @@ class TestRestApiHandler(unittest.TestCase):
         MockRestApiServer(RestApiHandler, request)
         mock_dcs.set_config_value.return_value = False
         MockRestApiServer(RestApiHandler, request)
+        mock_dcs.get_cluster.return_value.config = None
+        MockRestApiServer(RestApiHandler, request)
 
     @patch.object(MockPatroni, 'dcs')
     def test_do_PUT_config(self, mock_dcs):
@@ -307,6 +416,15 @@ class TestRestApiHandler(unittest.TestCase):
                 request = 'DELETE /restart HTTP/1.0' + self._authorization
                 self.assertIsNotNone(MockRestApiServer(RestApiHandler, request))
 
+    @patch.object(MockPatroni, 'dcs')
+    def test_do_DELETE_switchover(self, mock_dcs):
+        request = 'DELETE /switchover HTTP/1.0' + self._authorization
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, request))
+        mock_dcs.manual_failover.return_value = False
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, request))
+        mock_dcs.get_cluster.return_value.failover = None
+        self.assertIsNotNone(MockRestApiServer(RestApiHandler, request))
+
     @patch.object(MockPatroni, 'dcs')
     def test_do_POST_reinitialize(self, mock_dcs):
         cluster = mock_dcs.get_cluster.return_value
@@ -318,9 +436,9 @@ class TestRestApiHandler(unittest.TestCase):
 
     @patch('time.sleep', Mock())
     def test_RestApiServer_query(self):
-        with patch.object(MockCursor, 'execute', Mock(side_effect=psycopg2.OperationalError)):
+        with patch.object(MockCursor, 'execute', Mock(side_effect=psycopg.OperationalError)):
             self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /patroni'))
-        with patch.object(MockPostgresql, 'connection', Mock(side_effect=psycopg2.OperationalError)):
+        with patch.object(MockPostgresql, 'connection', Mock(side_effect=psycopg.OperationalError)):
             self.assertIsNotNone(MockRestApiServer(RestApiHandler, 'GET /patroni'))
 
     @patch('time.sleep', Mock())
@@ -413,25 +531,38 @@ class TestRestApiHandler(unittest.TestCase):
         MockRestApiServer(RestApiHandler, post + '37\n\n{"candidate":"2","scheduled_at": "1"}')
 
 
-@patch('ssl.SSLContext.load_cert_chain', Mock())
-@patch('ssl.SSLContext.wrap_socket', Mock(return_value=0))
-@patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock())
 class TestRestApiServer(unittest.TestCase):
 
+    @patch('ssl.SSLContext.load_cert_chain', Mock())
+    @patch('ssl.SSLContext.set_ciphers', Mock())
+    @patch('ssl.SSLContext.wrap_socket', Mock(return_value=0))
+    @patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock())
+    def setUp(self):
+        self.srv = MockRestApiServer(Mock(), '', {'listen': '*:8008', 'certfile': 'a', 'verify_client': 'required',
+                                                  'ciphers': '!SSLv1:!SSLv2:!SSLv3:!TLSv1:!TLSv1.1',
+                                                  'allowlist': ['127.0.0.1', '::1/128', '::1/zxc'],
+                                                  'allowlist_include_members': True})
+
+    @patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock())
     def test_reload_config(self):
         bad_config = {'listen': 'foo'}
         self.assertRaises(ValueError, MockRestApiServer, None, '', bad_config)
-        srv = MockRestApiServer(Mock(), '', {'listen': '*:8008', 'certfile': 'a', 'verify_client': 'required'})
-        self.assertRaises(ValueError, srv.reload_config, bad_config)
-        self.assertRaises(ValueError, srv.reload_config, {})
+        self.assertRaises(ValueError, self.srv.reload_config, bad_config)
+        self.assertRaises(ValueError, self.srv.reload_config, {})
         with patch.object(socket.socket, 'setsockopt', Mock(side_effect=socket.error)):
-            srv.reload_config({'listen': ':8008'})
+            self.srv.reload_config({'listen': ':8008'})
 
-    def test_check_auth(self):
-        srv = MockRestApiServer(Mock(), '', {'listen': '*:8008', 'certfile': 'a', 'verify_client': 'required'})
+    @patch.object(MockPatroni, 'dcs')
+    def test_check_access(self, mock_dcs):
+        mock_dcs.cluster = get_cluster_initialized_without_leader()
+        mock_dcs.cluster.members[1].data['api_url'] = 'http://127.0.0.1z:8011/patroni'
+        mock_dcs.cluster.members.append(Member(0, 'bad-api-url', 30, {'api_url': 123}))
         mock_rh = Mock()
+        mock_rh.client_address = ('127.0.0.2',)
+        self.assertIsNot(self.srv.check_access(mock_rh), True)
+        mock_rh.client_address = ('127.0.0.1',)
         mock_rh.request.getpeercert.return_value = None
-        self.assertIsNot(srv.check_auth(mock_rh), True)
+        self.assertIsNot(self.srv.check_access(mock_rh), True)
 
     def test_handle_error(self):
         try:
@@ -439,6 +570,37 @@ class TestRestApiServer(unittest.TestCase):
         except Exception:
             self.assertIsNone(MockRestApiServer.handle_error(None, ('127.0.0.1', 55555)))
 
+    @patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock(side_effect=socket.error))
     def test_socket_error(self):
-        with patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock(side_effect=socket.error)):
-            self.assertRaises(socket.error, MockRestApiServer, Mock(), '', {'listen': '*:8008'})
+        self.assertRaises(socket.error, MockRestApiServer, Mock(), '', {'listen': '*:8008'})
+
+    @patch.object(MockRestApiServer, 'finish_request', Mock())
+    def test_process_request_thread(self):
+        mock_socket = Mock()
+        self.srv.process_request_thread((mock_socket, 1), '2')
+        mock_socket.context.wrap_socket.side_effect = socket.error
+        self.srv.process_request_thread((mock_socket, 1), '2')
+
+    @patch.object(socket.socket, 'accept')
+    def test_get_request(self, mock_accept):
+        newsock = Mock()
+        mock_accept.return_value = (newsock, '2')
+        self.srv.socket = Mock()
+        self.assertEqual(self.srv.get_request(), ((self.srv.socket, newsock), '2'))
+
+    @patch.object(MockRestApiServer, 'process_request', Mock(side_effect=RuntimeError))
+    def test_process_request_error(self):
+        mock_address = ('127.0.0.1', 55555)
+        mock_socket = Mock()
+        mock_ssl_socket = (Mock(), Mock())
+        for mock_request in (mock_socket, mock_ssl_socket):
+            with patch.object(
+                MockRestApiServer,
+                'get_request',
+                Mock(return_value=(mock_request, mock_address))
+            ):
+                self.srv._handle_request_noblock()
+
+    @patch('ssl._ssl._test_decode_cert', Mock())
+    def test_reload_local_certificate(self):
+        self.assertTrue(self.srv.reload_local_certificate())

tests/test_bootstrap.py

@@ -8,11 +8,11 @@ from patroni.postgresql.bootstrap import Bootstrap
 from patroni.postgresql.cancellable import CancellableSubprocess
 from patroni.postgresql.config import ConfigHandler
 
-from . import psycopg2_connect, BaseTestPostgresql
+from . import psycopg_connect, BaseTestPostgresql
 
 
 @patch('subprocess.call', Mock(return_value=0))
-@patch('psycopg2.connect', psycopg2_connect)
+@patch('patroni.psycopg.connect', psycopg_connect)
 @patch('os.rename', Mock())
 class TestBootstrap(BaseTestPostgresql):
 
@@ -164,6 +164,7 @@ class TestBootstrap(BaseTestPostgresql):
     @patch('os.unlink', Mock())
     @patch('shutil.copy', Mock())
     @patch('os.path.isfile', Mock(return_value=True))
+    @patch('patroni.postgresql.bootstrap.quote_ident', Mock())
     @patch.object(Bootstrap, 'call_post_bootstrap', Mock(return_value=True))
     @patch.object(Bootstrap, '_custom_bootstrap', Mock(return_value=True))
     @patch.object(Postgresql, 'start', Mock(return_value=True))

tests/test_callback_executor.py

@@ -14,6 +14,7 @@ class TestCallbackExecutor(unittest.TestCase):
 
         ce = CallbackExecutor()
         ce._kill_children = Mock(side_effect=Exception)
+        ce._invoke_excepthook = Mock()
         self.assertIsNone(ce.call([]))
         ce.join()
 
@@ -30,5 +31,6 @@ class TestCallbackExecutor(unittest.TestCase):
         mock_popen.side_effect = Exception
         ce = CallbackExecutor()
         ce._condition.wait = Mock(side_effect=[None, Exception])
+        ce._invoke_excepthook = Mock()
         self.assertIsNone(ce.call([]))
         ce.join()

tests/test_cancellable.py

@@ -13,7 +13,7 @@ class TestCancellableSubprocess(unittest.TestCase):
 
     def test_call(self):
         self.c.cancel()
-        self.assertRaises(PostgresException, self.c.call, communicate_input=None)
+        self.assertRaises(PostgresException, self.c.call)
 
     def test__kill_children(self):
         self.c._process_children = [Mock()]

tests/test_config.py

@@ -1,9 +1,10 @@
 import os
 import sys
 import unittest
+import io
 
 from mock import MagicMock, Mock, patch
-from patroni.config import Config
+from patroni.config import Config, ConfigParseError
 from six.moves import builtins
 
 
@@ -29,12 +30,14 @@ class TestConfig(unittest.TestCase):
             'PATRONI_SCOPE': 'batman2',
             'PATRONI_LOGLEVEL': 'ERROR',
             'PATRONI_LOG_LOGGERS': 'patroni.postmaster: WARNING, urllib3: DEBUG',
+            'PATRONI_LOG_FILE_NUM': '5',
             'PATRONI_RESTAPI_USERNAME': 'username',
             'PATRONI_RESTAPI_PASSWORD': 'password',
             'PATRONI_RESTAPI_LISTEN': '0.0.0.0:8008',
             'PATRONI_RESTAPI_CONNECT_ADDRESS': '127.0.0.1:8008',
             'PATRONI_RESTAPI_CERTFILE': '/certfile',
             'PATRONI_RESTAPI_KEYFILE': '/keyfile',
+            'PATRONI_RESTAPI_ALLOWLIST_INCLUDE_MEMBERS': 'on',
             'PATRONI_POSTGRESQL_LISTEN': '0.0.0.0:5432',
             'PATRONI_POSTGRESQL_CONNECT_ADDRESS': '127.0.0.1:5432',
             'PATRONI_POSTGRESQL_DATA_DIR': 'data/postgres0',
@@ -55,6 +58,7 @@ class TestConfig(unittest.TestCase):
             'PATRONI_ZOOKEEPER_HOSTS': "'host1:2181','host2:2181'",
             'PATRONI_EXHIBITOR_HOSTS': 'host1,host2',
             'PATRONI_EXHIBITOR_PORT': '8181',
+            'PATRONI_RAFT_PARTNER_ADDRS': "'host1:1234','host2:1234'",
             'PATRONI_foo_HOSTS': '[host1,host2',  # Exception in parse_list
             'PATRONI_SUPERUSER_USERNAME': 'postgres',
             'PATRONI_SUPERUSER_PASSWORD': 'zalando',
@@ -94,3 +98,46 @@ class TestConfig(unittest.TestCase):
         self.config.set_dynamic_configuration(dynamic_configuration)
         for name, value in dynamic_configuration['standby_cluster'].items():
             self.assertEqual(self.config['standby_cluster'][name], value)
+
+    @patch('os.path.exists', Mock(return_value=True))
+    @patch('os.path.isfile', Mock(side_effect=lambda fname: fname != 'postgres0'))
+    @patch('os.path.isdir', Mock(return_value=True))
+    @patch('os.listdir', Mock(return_value=['01-specific.yml', '00-base.yml']))
+    def test_configuration_directory(self):
+        def open_mock(fname, *args, **kwargs):
+            if fname.endswith('00-base.yml'):
+                return io.StringIO(
+                    u'''
+                    test: True
+                    test2:
+                      child-1: somestring
+                      child-2: 5
+                      child-3: False
+                    test3: True
+                    test4:
+                     - abc: 3
+                     - abc: 4
+                    ''')
+            elif fname.endswith('01-specific.yml'):
+                return io.StringIO(
+                    u'''
+                    test: False
+                    test2:
+                      child-2: 10
+                      child-3: !!null
+                    test4:
+                     - ab: 5
+                    new-attr: True
+                    ''')
+
+        with patch.object(builtins, 'open', MagicMock(side_effect=open_mock)):
+            config = Config('postgres0')
+            self.assertEqual(config._local_configuration,
+                             {'test': False, 'test2': {'child-1': 'somestring', 'child-2': 10},
+                              'test3': True, 'test4': [{'ab': 5}], 'new-attr': True})
+
+    @patch('os.path.exists', Mock(return_value=True))
+    @patch('os.path.isfile', Mock(return_value=False))
+    @patch('os.path.isdir', Mock(return_value=False))
+    def test_invalid_path(self):
+        self.assertRaises(ConfigParseError, Config, 'postgres0')

tests/test_consul.py

@@ -2,9 +2,9 @@ import consul
 import unittest
 
 from consul import ConsulException, NotFound
-from mock import Mock, patch
+from mock import Mock, PropertyMock, patch
 from patroni.dcs.consul import AbstractDCS, Cluster, Consul, ConsulInternalError, \
-                                ConsulError, HTTPClient, InvalidSessionTTL, InvalidSession
+                                ConsulError, ConsulClient, HTTPClient, InvalidSessionTTL, InvalidSession
 from . import SleepException
 
 
@@ -15,8 +15,7 @@ def kv_get(self, key, **kwargs):
         return None, None
     if key == 'service/good/leader':
         return '1', None
-    if key == 'service/good/':
-        return ('6429',
+    good_cls = ('6429',
                 [{'CreateIndex': 1334, 'Flags': 0, 'Key': key + 'failover', 'LockIndex': 0,
                   'ModifyIndex': 1334, 'Value': b''},
                  {'CreateIndex': 1334, 'Flags': 0, 'Key': key + 'initialize', 'LockIndex': 0,
@@ -34,14 +33,25 @@ def kv_get(self, key, **kwargs):
                  {'CreateIndex': 1085, 'Flags': 0, 'Key': key + 'optime/leader', 'LockIndex': 0,
                   'ModifyIndex': 6429, 'Value': b'4496294792'},
                  {'CreateIndex': 1085, 'Flags': 0, 'Key': key + 'sync', 'LockIndex': 0,
-                  'ModifyIndex': 6429, 'Value': b'{"leader": "leader", "sync_standby": null}'}])
+                  'ModifyIndex': 6429, 'Value': b'{"leader": "leader", "sync_standby": null}'},
+                 {'CreateIndex': 1085, 'Flags': 0, 'Key': key + 'status', 'LockIndex': 0,
+                  'ModifyIndex': 6429, 'Value': b'{"optime":4496294792, "slots":{"ls":12345}}'}])
+    if key == 'service/good/':
+        return good_cls
+    if key == 'service/broken/':
+        good_cls[1][-1]['Value'] = b'{'
+        return good_cls
+    if key == 'service/legacy/':
+        good_cls[1].pop()
+        return good_cls
     raise ConsulException
 
 
 class TestHTTPClient(unittest.TestCase):
 
     def setUp(self):
-        self.client = HTTPClient('127.0.0.1', '8500', 'http', False)
+        c = ConsulClient()
+        self.client = c.http
         self.client.http.request = Mock()
 
     def test_get(self):
@@ -108,6 +118,10 @@ class TestConsul(unittest.TestCase):
         self.assertIsInstance(self.c.get_cluster(), Cluster)
         self.c._base_path = '/service/fail'
         self.assertRaises(ConsulError, self.c.get_cluster)
+        self.c._base_path = '/service/broken'
+        self.assertIsInstance(self.c.get_cluster(), Cluster)
+        self.c._base_path = '/service/legacy'
+        self.assertIsInstance(self.c.get_cluster(), Cluster)
         self.c._base_path = '/service/good'
         self.c._session = 'fd4f44fe-2cac-bba5-a60b-304b51ff39b8'
         self.assertIsInstance(self.c.get_cluster(), Cluster)
@@ -116,12 +130,15 @@ class TestConsul(unittest.TestCase):
     @patch.object(consul.Consul.KV, 'put', Mock(side_effect=[True, ConsulException, InvalidSession]))
     def test_touch_member(self):
         self.c.refresh_session = Mock(return_value=False)
-        self.c.touch_member({'conn_url': 'postgres://replicator:[email protected]:5433/postgres',
-                             'api_url': 'http://127.0.0.1:8009/patroni'})
+        with patch.object(Consul, 'update_service', Mock(side_effect=Exception)):
+            self.c.touch_member({'conn_url': 'postgres://replicator:[email protected]:5433/postgres',
+                                 'api_url': 'http://127.0.0.1:8009/patroni'})
         self.c._register_service = True
         self.c.refresh_session = Mock(return_value=True)
         for _ in range(0, 4):
             self.c.touch_member({'balbla': 'blabla'})
+        self.c.refresh_session = Mock(side_effect=ConsulError('foo'))
+        self.assertFalse(self.c.touch_member({'balbla': 'blabla'}))
 
     @patch.object(consul.Consul.KV, 'put', Mock(side_effect=InvalidSession))
     def test_take_leader(self):
@@ -137,13 +154,15 @@ class TestConsul(unittest.TestCase):
     def test_set_config_value(self):
         self.c.set_config_value('')
 
+    @patch.object(Cluster, 'min_version', PropertyMock(return_value=(2, 0)))
     @patch.object(consul.Consul.KV, 'put', Mock(side_effect=ConsulException))
     def test_write_leader_optime(self):
+        self.c.get_cluster()
         self.c.write_leader_optime('1')
 
     @patch.object(consul.Consul.Session, 'renew', Mock())
     def test_update_leader(self):
-        self.c.update_leader(None)
+        self.c.update_leader(12345)
 
     @patch.object(consul.Consul.KV, 'delete', Mock(return_value=True))
     def test_delete_leader(self):
@@ -199,4 +218,50 @@ class TestConsul(unittest.TestCase):
         self.assertIsNone(self.c.update_service({}, d))
 
     def test_reload_config(self):
-        self.c.reload_config({'consul': {'token': 'foo'}, 'loop_wait': 10, 'ttl': 30, 'retry_timeout': 10})
+        self.assertEqual([], self.c._service_tags)
+        self.c.reload_config({'consul': {'token': 'foo', 'register_service': True, 'service_tags': ['foo']},
+                              'loop_wait': 10, 'ttl': 30, 'retry_timeout': 10})
+        self.assertEqual(["foo"], self.c._service_tags)
+
+        self.c.refresh_session = Mock(return_value=False)
+
+        d = {'role': 'replica', 'api_url': 'http://a/t', 'conn_url': 'pg://c:1', 'state': 'running'}
+
+        # Changing register_service from True to False calls deregister()
+        self.c.reload_config({'consul': {'register_service': False}, 'loop_wait': 10, 'ttl': 30, 'retry_timeout': 10})
+        with patch('consul.Consul.Agent.Service.deregister') as mock_deregister:
+            self.c.touch_member(d)
+            mock_deregister.assert_called_once()
+
+        self.assertEqual([], self.c._service_tags)
+
+        # register_service staying False between reloads does not call deregister()
+        self.c.reload_config({'consul': {'register_service': False}, 'loop_wait': 10, 'ttl': 30, 'retry_timeout': 10})
+        with patch('consul.Consul.Agent.Service.deregister') as mock_deregister:
+            self.c.touch_member(d)
+            self.assertFalse(mock_deregister.called)
+
+        # Changing register_service from False to True calls register()
+        self.c.reload_config({'consul': {'register_service': True}, 'loop_wait': 10, 'ttl': 30, 'retry_timeout': 10})
+        with patch('consul.Consul.Agent.Service.register') as mock_register:
+            self.c.touch_member(d)
+            mock_register.assert_called_once()
+
+        # register_service staying True between reloads does not call register()
+        self.c.reload_config({'consul': {'register_service': True}, 'loop_wait': 10, 'ttl': 30, 'retry_timeout': 10})
+        with patch('consul.Consul.Agent.Service.register') as mock_register:
+            self.c.touch_member(d)
+            self.assertFalse(mock_deregister.called)
+
+        # register_service staying True between reloads does calls register() if other service data has changed
+        self.c.reload_config({'consul': {'register_service': True}, 'loop_wait': 10, 'ttl': 30, 'retry_timeout': 10})
+        with patch('consul.Consul.Agent.Service.register') as mock_register:
+            self.c.touch_member(d)
+            mock_register.assert_called_once()
+
+        # register_service staying True between reloads does calls register() if service_tags have changed
+        self.c.reload_config({'consul': {'register_service': True, 'service_tags': ['foo']}, 'loop_wait': 10,
+                              'ttl': 30, 'retry_timeout': 10})
+        with patch('consul.Consul.Agent.Service.register') as mock_register:
+            self.c.touch_member(d)
+            mock_register.assert_called_once()

tests/test_ctl.py

@@ -7,13 +7,13 @@ from datetime import datetime, timedelta
 from mock import patch, Mock
 from patroni.ctl import ctl, store_config, load_config, output_members, get_dcs, parse_dcs, \
     get_all_members, get_any_member, get_cursor, query_member, configure, PatroniCtlException, apply_config_changes, \
-    format_config_for_editing, show_diff, invoke_editor, format_pg_version, find_executable, CONFIG_FILE_PATH
-from patroni.dcs.etcd import Client, Failover
+    format_config_for_editing, show_diff, invoke_editor, format_pg_version, CONFIG_FILE_PATH
+from patroni.dcs.etcd import AbstractEtcdClientWithFailover, Failover
+from patroni.psycopg import OperationalError
 from patroni.utils import tzutc
-from psycopg2 import OperationalError
 from urllib3 import PoolManager
 
-from . import MockConnect, MockCursor, MockResponse, psycopg2_connect
+from . import MockConnect, MockCursor, MockResponse, psycopg_connect
 from .test_etcd import etcd_read, socket_getaddrinfo
 from .test_ha import get_cluster_initialized_without_leader, get_cluster_initialized_with_leader, \
     get_cluster_initialized_with_only_leader, get_cluster_not_initialized_without_leader, get_cluster, Member
@@ -37,7 +37,7 @@ class TestCtl(unittest.TestCase):
 
     @patch('socket.getaddrinfo', socket_getaddrinfo)
     def setUp(self):
-        with patch.object(Client, 'machines') as mock_machines:
+        with patch.object(AbstractEtcdClientWithFailover, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
             self.runner = CliRunner()
             self.e = get_dcs({'etcd': {'ttl': 30, 'host': 'ok:2379', 'retry_timeout': 10}}, 'foo')
@@ -48,7 +48,7 @@ class TestCtl(unittest.TestCase):
             self.assertRaises(PatroniCtlException, load_config, './non-existing-config-file', None)
             self.assertRaises(PatroniCtlException, load_config, './non-existing-config-file', None)
 
-    @patch('psycopg2.connect', psycopg2_connect)
+    @patch('patroni.psycopg.connect', psycopg_connect)
     def test_get_cursor(self):
         self.assertIsNone(get_cursor(get_cluster_initialized_without_leader(), {}, role='master'))
 
@@ -57,7 +57,7 @@ class TestCtl(unittest.TestCase):
         # MockCursor returns pg_is_in_recovery as false
         self.assertIsNone(get_cursor(get_cluster_initialized_with_leader(), {}, role='replica'))
 
-        self.assertIsNotNone(get_cursor(get_cluster_initialized_with_leader(), {'database': 'foo'}, role='any'))
+        self.assertIsNotNone(get_cursor(get_cluster_initialized_with_leader(), {'dbname': 'foo'}, role='any'))
 
     def test_parse_dcs(self):
         assert parse_dcs(None) is None
@@ -73,7 +73,7 @@ class TestCtl(unittest.TestCase):
         scheduled_at = datetime.now(tzutc) + timedelta(seconds=600)
         cluster = get_cluster_initialized_with_leader(Failover(1, 'foo', 'bar', scheduled_at))
         del cluster.members[1].data['conn_url']
-        for fmt in ('pretty', 'json', 'yaml', 'tsv'):
+        for fmt in ('pretty', 'json', 'yaml', 'tsv', 'topology'):
             self.assertIsNone(output_members(cluster, name='abc', fmt=fmt))
 
     @patch('patroni.ctl.get_dcs')
@@ -165,7 +165,7 @@ class TestCtl(unittest.TestCase):
     def test_get_dcs(self):
         self.assertRaises(PatroniCtlException, get_dcs, {'dummy': {}}, 'dummy')
 
-    @patch('psycopg2.connect', psycopg2_connect)
+    @patch('patroni.psycopg.connect', psycopg_connect)
     @patch('patroni.ctl.query_member', Mock(return_value=([['mock column']], None)))
     @patch('patroni.ctl.get_dcs')
     @patch.object(etcd.Client, 'read', etcd_read)
@@ -417,9 +417,39 @@ class TestCtl(unittest.TestCase):
         assert '2100' in result.output
         assert 'Scheduled restart' in result.output
 
+    @patch('patroni.ctl.get_dcs')
+    def test_topology(self, mock_get_dcs):
+        mock_get_dcs.return_value = self.e
+        cluster = get_cluster_initialized_with_leader()
+        cascade_member = Member(0, 'cascade', 28, {'conn_url': 'postgres://replicator:[email protected]:5437/postgres',
+                                                   'api_url': 'http://127.0.0.1:8012/patroni',
+                                                   'state': 'running',
+                                                   'tags': {'replicatefrom': 'other'},
+                                                   })
+        cascade_member_wrong_tags = Member(0, 'wrong_cascade', 28,
+                                           {'conn_url': 'postgres://replicator:[email protected]:5438/postgres',
+                                            'api_url': 'http://127.0.0.1:8013/patroni',
+                                            'state': 'running',
+                                            'tags': {'replicatefrom': 'nonexistinghost'},
+                                            })
+        cluster.members.append(cascade_member)
+        cluster.members.append(cascade_member_wrong_tags)
+        mock_get_dcs.return_value.get_cluster = Mock(return_value=cluster)
+        result = self.runner.invoke(ctl, ['topology', 'dummy'])
+        assert '+\n| leader          | 127.0.0.1:5435 | Leader  |' in result.output
+        assert '|\n| + other         | 127.0.0.1:5436 | Replica |' in result.output
+        assert '|\n|   + cascade     | 127.0.0.1:5437 | Replica |' in result.output
+        assert '|\n| + wrong_cascade | 127.0.0.1:5438 | Replica |' in result.output
+
+        cluster = get_cluster_initialized_without_leader()
+        mock_get_dcs.return_value.get_cluster = Mock(return_value=cluster)
+        result = self.runner.invoke(ctl, ['topology', 'dummy'])
+        assert '+\n| + leader | 127.0.0.1:5435 | Replica |' in result.output
+        assert '|\n| + other  | 127.0.0.1:5436 | Replica |' in result.output
+
     @patch('patroni.ctl.get_dcs')
     @patch.object(PoolManager, 'request', Mock(return_value=MockResponse()))
-    def test_flush(self, mock_get_dcs):
+    def test_flush_restart(self, mock_get_dcs):
         mock_get_dcs.return_value = self.e
         mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
 
@@ -432,6 +462,26 @@ class TestCtl(unittest.TestCase):
             result = self.runner.invoke(ctl, ['flush', 'dummy', 'restart', '--force'])
             assert 'Failed: flush scheduled restart' in result.output
 
+    @patch('patroni.ctl.get_dcs')
+    @patch.object(PoolManager, 'request', Mock(return_value=MockResponse()))
+    def test_flush_switchover(self, mock_get_dcs):
+        mock_get_dcs.return_value = self.e
+
+        mock_get_dcs.return_value.get_cluster = get_cluster_initialized_with_leader
+        result = self.runner.invoke(ctl, ['flush', 'dummy', 'switchover'])
+        assert 'No pending scheduled switchover' in result.output
+
+        scheduled_at = datetime.now(tzutc) + timedelta(seconds=600)
+        mock_get_dcs.return_value.get_cluster = Mock(
+                return_value=get_cluster_initialized_with_leader(Failover(1, 'a', 'b', scheduled_at)))
+        result = self.runner.invoke(ctl, ['flush', 'dummy', 'switchover'])
+        assert result.output.startswith('Success: ')
+
+        mock_get_dcs.return_value.manual_failover = Mock()
+        with patch.object(PoolManager, 'request', side_effect=[MockResponse(409), Exception]):
+            result = self.runner.invoke(ctl, ['flush', 'dummy', 'switchover'])
+            assert 'Could not find any accessible member of cluster' in result.output
+
     @patch.object(PoolManager, 'request')
     @patch('patroni.ctl.get_dcs')
     @patch('patroni.ctl.polling_loop', Mock(return_value=[1]))
@@ -511,7 +561,7 @@ class TestCtl(unittest.TestCase):
         self.assertRaises(PatroniCtlException, apply_config_changes, before_editing, config, ['a'])
 
     @patch('sys.stdout.isatty', return_value=False)
-    @patch('cdiff.markup_to_pager')
+    @patch('patroni.ctl.markup_to_pager')
     def test_show_diff(self, mock_markup_to_pager, mock_isatty):
         show_diff("foo:\n  bar: 1\n", "foo:\n  bar: 2\n")
         mock_markup_to_pager.assert_not_called()
@@ -520,6 +570,9 @@ class TestCtl(unittest.TestCase):
         show_diff("foo:\n  bar: 1\n", "foo:\n  bar: 2\n")
         mock_markup_to_pager.assert_called_once()
 
+        with patch('patroni.ctl.find_executable', Mock(return_value=None)):
+            show_diff("foo:\n  bar: 1\n", "foo:\n  bar: 2\n")
+
         # Test that unicode handling doesn't fail with an exception
         show_diff(b"foo:\n  bar: \xc3\xb6\xc3\xb6\n".decode('utf-8'),
                   b"foo:\n  bar: \xc3\xbc\xc3\xbc\n".decode('utf-8'))
@@ -576,15 +629,6 @@ class TestCtl(unittest.TestCase):
         self.assertEqual(format_pg_version(100001), '10.1')
         self.assertEqual(format_pg_version(90605), '9.6.5')
 
-    @patch('sys.platform', 'win32')
-    def test_find_executable(self):
-        with patch('os.path.isfile', Mock(return_value=True)):
-            self.assertEqual(find_executable('vim'), 'vim.exe')
-        with patch('os.path.isfile', Mock(return_value=False)):
-            self.assertIsNone(find_executable('vim'))
-        with patch('os.path.isfile', Mock(side_effect=[False, True])):
-            self.assertEqual(find_executable('vim', '/'), '/vim.exe')
-
     @patch('patroni.ctl.get_dcs')
     def test_get_members(self, mock_get_dcs):
         mock_get_dcs.return_value = self.e

tests/test_etcd.py

@@ -4,8 +4,8 @@ import socket
 import unittest
 
 from dns.exception import DNSException
-from mock import Mock, patch
-from patroni.dcs.etcd import AbstractDCS, Client, Cluster, Etcd, EtcdError, DnsCachingResolver
+from mock import Mock, PropertyMock, patch
+from patroni.dcs.etcd import AbstractDCS, EtcdClient, Cluster, Etcd, EtcdError, DnsCachingResolver
 from patroni.exceptions import DCSError
 from patroni.utils import Retry
 from urllib3.exceptions import ReadTimeoutError
@@ -17,7 +17,7 @@ def etcd_watch(self, key, index=None, timeout=None, recursive=None):
     if timeout == 2.0:
         raise etcd.EtcdWatchTimedOut
     elif timeout == 5.0:
-        return etcd.EtcdResult('delete', {})
+        return etcd.EtcdResult('compareAndSwap', {})
     elif 5 < timeout <= 10.0:
         raise etcd.EtcdException
     elif timeout == 20.0:
@@ -66,7 +66,13 @@ def etcd_read(self, key, **kwargs):
                         "?application_name=http://127.0.0.1:8008/patroni",
                      "expiration": "2015-05-15T09:11:09.611860899Z", "ttl": 30,
                      "modifiedIndex": 20730, "createdIndex": 20730}],
-                 "modifiedIndex": 1581, "createdIndex": 1581}], "modifiedIndex": 1581, "createdIndex": 1581}}
+                 "modifiedIndex": 1581, "createdIndex": 1581},
+                {"key": "/service/batman5/status", "value": '{"optime":2164261704,"slots":{"ls":12345}}',
+                 "modifiedIndex": 1582, "createdIndex": 1582}], "modifiedIndex": 1581, "createdIndex": 1581}}
+    if key == '/service/legacy/':
+        response['node']['nodes'].pop()
+    if key == '/service/broken/':
+        response['node']['nodes'][-1]['value'] = '{'
     result = etcd.EtcdResult(**response)
     result.etcd_index = 0
     return result
@@ -81,7 +87,8 @@ def dns_query(name, _):
         raise DNSException()
     srv = Mock()
     srv.port = 2380
-    srv.target.to_text.return_value = 'localhost' if name == '_etcd-server._tcp.foobar' else '127.0.0.1'
+    srv.target.to_text.return_value = \
+        'localhost' if name in ['_etcd-server._tcp.foobar', '_etcd-server-baz._tcp.foobar'] else '127.0.0.1'
     return [srv]
 
 
@@ -110,6 +117,7 @@ class TestDnsCachingResolver(unittest.TestCase):
     @patch('socket.getaddrinfo', Mock(side_effect=socket.gaierror))
     def test_run(self):
         r = DnsCachingResolver()
+        r._invoke_excepthook = Mock()
         self.assertIsNone(r.resolve_async('', 0))
         r.join()
 
@@ -123,9 +131,9 @@ class TestClient(unittest.TestCase):
     @patch('socket.getaddrinfo', socket_getaddrinfo)
     @patch('patroni.dcs.etcd.requests_get', requests_get)
     def setUp(self):
-        with patch.object(Client, 'machines') as mock_machines:
+        with patch.object(EtcdClient, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
-            self.client = Client({'srv': 'test', 'retry_timeout': 3}, DnsCachingResolver())
+            self.client = EtcdClient({'srv': 'test', 'retry_timeout': 3}, DnsCachingResolver())
             self.client.http.request = http_request
             self.client.http.request_encode_body = http_request
 
@@ -143,10 +151,9 @@ class TestClient(unittest.TestCase):
         except Exception:
             self.assertIsNone(machines)
 
-    @patch.object(Client, 'machines')
+    @patch.object(EtcdClient, 'machines')
     def test_api_execute(self, mock_machines):
         mock_machines.__get__ = Mock(return_value=['http://localhost:4001', 'http://localhost:2379'])
-        self.assertRaises(ValueError, self.client.api_execute, '', '')
         self.client._base_uri = 'http://localhost:4001'
         self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', 'POST', timeout=0)
         self.client._base_uri = 'http://localhost:4001'
@@ -157,18 +164,17 @@ class TestClient(unittest.TestCase):
         self.client._machines_cache = [self.client._base_uri]
         self.assertRaises(etcd.EtcdWatchTimedOut, self.client.api_execute, '/timeout', 'POST', params={'wait': 'true'})
         self.assertRaises(etcd.EtcdWatchTimedOut, self.client.api_execute, '/timeout', 'POST', params={'wait': 'true'})
-        self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', '')
 
-        with patch.object(Client, '_calculate_timeouts', Mock(side_effect=[(1, 1, 0), (1, 1, 0), (0, 1, 0)])),\
-                patch.object(Client, '_load_machines_cache', Mock(side_effect=Exception)):
+        with patch.object(EtcdClient, '_calculate_timeouts', Mock(side_effect=[(1, 1, 0), (1, 1, 0), (0, 1, 0)])),\
+                patch.object(EtcdClient, '_load_machines_cache', Mock(side_effect=Exception)):
             self.client.http.request = Mock(side_effect=socket.error)
             self.assertRaises(etcd.EtcdException, rtry, self.client.api_execute, '/', 'GET', params={'retry': rtry})
 
-        with patch.object(Client, '_calculate_timeouts', Mock(side_effect=[(1, 1, 0), (1, 1, 0), (0, 1, 0)])),\
-                patch.object(Client, '_load_machines_cache', Mock(return_value=True)):
+        with patch.object(EtcdClient, '_calculate_timeouts', Mock(side_effect=[(1, 1, 0), (1, 1, 0), (0, 1, 0)])),\
+                patch.object(EtcdClient, '_load_machines_cache', Mock(return_value=True)):
             self.assertRaises(etcd.EtcdException, rtry, self.client.api_execute, '/', 'GET', params={'retry': rtry})
 
-        with patch.object(Client, '_do_http_request', Mock(side_effect=etcd.EtcdException)):
+        with patch.object(EtcdClient, '_do_http_request', Mock(side_effect=etcd.EtcdException)):
             self.client._read_timeout = 0.01
             self.assertRaises(etcd.EtcdException, self.client.api_execute, '/', 'GET')
 
@@ -178,13 +184,14 @@ class TestClient(unittest.TestCase):
 
     def test__get_machines_cache_from_srv(self):
         self.client._get_machines_cache_from_srv('foobar')
+        self.client._get_machines_cache_from_srv('foobar', 'baz')
         self.client.get_srv_record = Mock(return_value=[('localhost', 2380)])
         self.client._get_machines_cache_from_srv('blabla')
 
     def test__get_machines_cache_from_dns(self):
         self.client._get_machines_cache_from_dns('error', 2379)
 
-    @patch.object(Client, 'machines')
+    @patch.object(EtcdClient, 'machines')
     def test__refresh_machines_cache(self, mock_machines):
         mock_machines.__get__ = Mock(side_effect=etcd.EtcdConnectionFailed)
         self.assertIsNone(self.client._refresh_machines_cache())
@@ -205,6 +212,10 @@ class TestClient(unittest.TestCase):
                           timeout=1, source_address=('localhost', 53333),
                           socket_options=[(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)])
 
+    def test___del__(self):
+        self.client.http.clear = Mock(side_effect=TypeError)
+        del self.client
+
 
 @patch('patroni.dcs.etcd.requests_get', requests_get)
 @patch('socket.getaddrinfo', socket_getaddrinfo)
@@ -215,7 +226,7 @@ class TestEtcd(unittest.TestCase):
 
     @patch('socket.getaddrinfo', socket_getaddrinfo)
     def setUp(self):
-        with patch.object(Client, 'machines') as mock_machines:
+        with patch.object(EtcdClient, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://localhost:2379', 'http://localhost:4001'])
             self.etcd = Etcd({'namespace': '/patroni/', 'ttl': 30, 'retry_timeout': 10,
                               'host': 'localhost:2379', 'scope': 'test', 'name': 'foo'})
@@ -226,22 +237,27 @@ class TestEtcd(unittest.TestCase):
     @patch('dns.resolver.query', dns_query)
     def test_get_etcd_client(self):
         with patch('time.sleep', Mock(side_effect=SleepException)),\
-                patch.object(Client, 'machines') as mock_machines:
+                patch.object(EtcdClient, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(side_effect=etcd.EtcdException)
             self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                              {'discovery_srv': 'test', 'retry_timeout': 10, 'cacert': '1', 'key': '1', 'cert': 1})
+                              {'discovery_srv': 'test', 'retry_timeout': 10, 'cacert': '1', 'key': '1', 'cert': 1},
+                              EtcdClient)
             self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                              {'url': 'https://test:2379', 'retry_timeout': 10})
+                              {'url': 'https://test:2379', 'retry_timeout': 10}, EtcdClient)
             self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                              {'hosts': 'foo:4001,bar', 'retry_timeout': 10})
+                              {'hosts': 'foo:4001,bar', 'retry_timeout': 10}, EtcdClient)
             mock_machines.__get__ = Mock(return_value=[])
             self.assertRaises(SleepException, self.etcd.get_etcd_client,
-                              {'proxy': 'https://user:password@test:2379', 'retry_timeout': 10})
+                              {'proxy': 'https://user:password@test:2379', 'retry_timeout': 10}, EtcdClient)
 
     def test_get_cluster(self):
         cluster = self.etcd.get_cluster()
         self.assertIsInstance(cluster, Cluster)
         self.assertFalse(cluster.is_synchronous_mode())
+        self.etcd._base_path = '/service/legacy'
+        self.assertIsInstance(self.etcd.get_cluster(), Cluster)
+        self.etcd._base_path = '/service/broken'
+        self.assertIsInstance(self.etcd.get_cluster(), Cluster)
         self.etcd._base_path = '/service/nocluster'
         cluster = self.etcd.get_cluster()
         self.assertIsInstance(cluster, Cluster)
@@ -261,7 +277,9 @@ class TestEtcd(unittest.TestCase):
         self.etcd._base_path = '/service/failed'
         self.assertFalse(self.etcd.attempt_to_acquire_leader())
 
+    @patch.object(Cluster, 'min_version', PropertyMock(return_value=(2, 0)))
     def test_write_leader_optime(self):
+        self.etcd.get_cluster()
         self.etcd.write_leader_optime('0')
 
     def test_update_leader(self):
@@ -285,7 +303,8 @@ class TestEtcd(unittest.TestCase):
         self.etcd.watch(None, 0)
         self.etcd.get_cluster()
         self.etcd.watch(20729, 1.5)
-        self.etcd.watch(20729, 4.5)
+        with patch('time.sleep', Mock()):
+            self.etcd.watch(20729, 4.5)
         with patch.object(AbstractDCS, 'watch', Mock()):
             self.assertTrue(self.etcd.watch(20729, 19.5))
             self.assertRaises(SleepException, self.etcd.watch, 20729, 9.5)
@@ -304,3 +323,6 @@ class TestEtcd(unittest.TestCase):
 
     def test_set_history_value(self):
         self.assertFalse(self.etcd.set_history_value('{}'))
+
+    def test_last_seen(self):
+        self.assertIsNotNone(self.etcd.last_seen)

tests/test_etcd3.py

@@ -0,0 +1,275 @@
+import etcd
+import json
+import unittest
+import urllib3
+
+from mock import Mock, patch
+from patroni.dcs.etcd import DnsCachingResolver
+from patroni.dcs.etcd3 import PatroniEtcd3Client, Cluster, Etcd3Client, Etcd3Error, Etcd3ClientError, RetryFailedError,\
+        InvalidAuthToken, Unavailable, Unknown, UnsupportedEtcdVersion, UserEmpty, AuthFailed, base64_encode, Etcd3
+from threading import Thread
+
+from . import SleepException, MockResponse
+
+
+def mock_urlopen(self, method, url, **kwargs):
+    ret = MockResponse()
+    if method == 'GET' and url.endswith('/version'):
+        ret.content = '{"etcdserver": "3.3.13", "etcdcluster": "3.3.0"}'
+    elif method != 'POST':
+        raise Exception('Unexpected request method: {0} {1} {2}'.format(method, url, kwargs))
+    elif url.endswith('/cluster/member/list'):
+        ret.content = '{"members":[{"clientURLs":["http://localhost:2379", "http://localhost:4001"]}]}'
+    elif url.endswith('/auth/authenticate'):
+        ret.content = '{"token":"authtoken"}'
+    elif url.endswith('/lease/grant'):
+        ret.content = '{"ID": "123"}'
+    elif url.endswith('/lease/keepalive'):
+        ret.content = '{"result":{"TTL":30}}'
+    elif url.endswith('/kv/range'):
+        ret.content = json.dumps({
+            "header": {"revision": "1"},
+            "kvs": [
+                {"key": base64_encode('/patroni/test/leader'),
+                 "value": base64_encode('foo'), "lease": "bla", "mod_revision": '1'},
+                {"key": base64_encode('/patroni/test/members/foo'),
+                 "value": base64_encode('{}'), "lease": "123", "mod_revision": '1'},
+                {"key": base64_encode('/patroni/test/members/bar'),
+                 "value": base64_encode('{"version":"1.6.5"}'), "lease": "123", "mod_revision": '1'},
+                {"key": base64_encode('/patroni/test/failover'), "value": base64_encode('{}'), "mod_revision": '1'}
+            ]
+        })
+    elif url.endswith('/watch'):
+        key = base64_encode('/patroni/test/config')
+        ret.read_chunked = Mock(return_value=[json.dumps({
+            'result': {'events': [
+                {'kv': {'key': key, 'value': base64_encode('bar'), 'mod_revision': '2'}},
+                {'kv': {'key': key, 'value': base64_encode('buzz'), 'mod_revision': '3'}},
+                {'type': 'DELETE', 'kv': {'key': key, 'mod_revision': '4'}},
+                {'kv': {'key': base64_encode('/patroni/test/optime/leader'),
+                        'value': base64_encode('1234567'), 'mod_revision': '5'}},
+            ]}
+        })[:-1].encode('utf-8'), b'}{"error":{"grpc_code":14,"message":"","http_code":503}}'])
+    elif url.endswith('/kv/put') or url.endswith('/kv/txn'):
+        ret.status_code = 400
+        ret.content = '{"code":5,"error":"etcdserver: requested lease not found"}'
+    elif not url.endswith('/kv/deleterange'):
+        raise Exception('Unexpected url: {0} {1} {2}'.format(method, url, kwargs))
+    return ret
+
+
+class TestEtcd3Client(unittest.TestCase):
+
+    @patch.object(Thread, 'start', Mock())
+    @patch.object(urllib3.PoolManager, 'urlopen', mock_urlopen)
+    def test_authenticate(self):
+        etcd3 = Etcd3Client({'host': '127.0.0.1', 'port': 2379, 'use_proxies': True, 'retry_timeout': 10},
+                            DnsCachingResolver())
+        self.assertIsNotNone(etcd3._cluster_version)
+
+
+class BaseTestEtcd3(unittest.TestCase):
+
+    @patch.object(Thread, 'start', Mock())
+    @patch.object(urllib3.PoolManager, 'urlopen', mock_urlopen)
+    def setUp(self):
+        self.etcd3 = Etcd3({'namespace': '/patroni/', 'ttl': 30, 'retry_timeout': 10,
+                            'host': 'localhost:2378', 'scope': 'test', 'name': 'foo',
+                            'username': 'etcduser', 'password': 'etcdpassword'})
+        self.client = self.etcd3._client
+        self.kv_cache = self.client._kv_cache
+
+
+class TestKVCache(BaseTestEtcd3):
+
+    def test__do_watch(self):
+        self.client.watchprefix = Mock(return_value=False)
+        self.assertRaises(AttributeError, self.kv_cache._do_watch, '1')
+
+    @patch('time.sleep', Mock(side_effect=SleepException))
+    @patch('patroni.dcs.etcd3.KVCache._build_cache', Mock(side_effect=Exception))
+    def test_run(self):
+        self.assertRaises(SleepException, self.kv_cache.run)
+
+    @patch.object(urllib3.PoolManager, 'urlopen', mock_urlopen)
+    def test_kill_stream(self):
+        self.assertRaises(Unavailable, self.kv_cache._do_watch, '1')
+        self.kv_cache.kill_stream()
+        with patch.object(MockResponse, 'connection', create=True) as mock_conn:
+            self.kv_cache.kill_stream()
+            mock_conn.sock.close.side_effect = Exception
+            self.kv_cache.kill_stream()
+
+
+class TestPatroniEtcd3Client(BaseTestEtcd3):
+
+    @patch('patroni.dcs.etcd3.Etcd3Client.authenticate', Mock(side_effect=AuthFailed))
+    def test__init__(self):
+        self.assertRaises(SystemExit, self.setUp)
+
+    @patch.object(urllib3.PoolManager, 'urlopen')
+    def test_call_rpc(self, mock_urlopen):
+        request = {'key': base64_encode('/patroni/test/leader')}
+        mock_urlopen.return_value = MockResponse()
+        mock_urlopen.return_value.content = '{"succeeded":true,"header":{"revision":"1"}}'
+        self.client.call_rpc('/kv/txn', {'success': [{'request_delete_range': request}]})
+        self.client.call_rpc('/kv/put', request)
+        self.client.call_rpc('/kv/deleterange', request)
+
+    @patch('time.time', Mock(side_effect=[1, 10.9, 100]))
+    def test__wait_cache(self):
+        with self.kv_cache.condition:
+            self.assertRaises(RetryFailedError, self.client._wait_cache, 10)
+
+    @patch.object(urllib3.PoolManager, 'urlopen')
+    def test__restart_watcher(self, mock_urlopen):
+        mock_urlopen.return_value = MockResponse()
+        mock_urlopen.return_value.status_code = 400
+        mock_urlopen.return_value.content = '{"code":9,"error":"etcdserver: authentication is not enabled"}'
+        self.client.authenticate()
+
+    @patch.object(urllib3.PoolManager, 'urlopen')
+    def test__handle_auth_errors(self, mock_urlopen):
+        mock_urlopen.return_value = MockResponse()
+        mock_urlopen.return_value.content = '{"code":3,"error":"etcdserver: user name is empty"}'
+        mock_urlopen.return_value.status_code = 403
+        self.client._cluster_version = (3, 1, 5)
+        self.assertRaises(UnsupportedEtcdVersion, self.client.deleteprefix, 'foo')
+        self.client._cluster_version = (3, 3, 13)
+        self.assertRaises(UserEmpty, self.client.deleteprefix, 'foo')
+        mock_urlopen.return_value.content = '{"code":16,"error":"etcdserver: invalid auth token"}'
+        self.assertRaises(InvalidAuthToken, self.client.deleteprefix, 'foo')
+        with patch.object(PatroniEtcd3Client, 'authenticate', Mock(return_value=True)):
+            self.assertRaises(InvalidAuthToken, self.client.deleteprefix, 'foo')
+            self.client.username = None
+            self.assertRaises(InvalidAuthToken, self.client.deleteprefix, 'foo')
+
+    def test__handle_server_response(self):
+        response = MockResponse()
+        response.content = '{"code":0,"error":"'
+        self.assertRaises(etcd.EtcdException, self.client._handle_server_response, response)
+        response.status_code = 400
+        self.assertRaises(Unknown, self.client._handle_server_response, response)
+        response.content = '{"error":{"grpc_code":0,"message":"","http_code":400}}'
+        try:
+            self.client._handle_server_response(response)
+        except Unknown as e:
+            self.assertEqual(e.as_dict(), {'code': 2, 'codeText': 'OK', 'error': u'', 'status': 400})
+
+    @patch.object(urllib3.PoolManager, 'urlopen')
+    def test__ensure_version_prefix(self, mock_urlopen):
+        self.client.version_prefix = None
+        mock_urlopen.return_value = MockResponse()
+        mock_urlopen.return_value.content = '{"etcdserver": "3.0.3", "etcdcluster": "3.0.0"}'
+        self.assertRaises(UnsupportedEtcdVersion, self.client._ensure_version_prefix, '')
+        mock_urlopen.return_value.content = '{"etcdserver": "3.0.4", "etcdcluster": "3.0.0"}'
+        self.client._ensure_version_prefix('')
+        self.assertEqual(self.client.version_prefix, '/v3alpha')
+        mock_urlopen.return_value.content = '{"etcdserver": "3.4.4", "etcdcluster": "3.4.0"}'
+        self.client._ensure_version_prefix('')
+        self.assertEqual(self.client.version_prefix, '/v3')
+
+
+@patch.object(urllib3.PoolManager, 'urlopen', mock_urlopen)
+class TestEtcd3(BaseTestEtcd3):
+
+    @patch.object(Thread, 'start', Mock())
+    @patch.object(urllib3.PoolManager, 'urlopen', mock_urlopen)
+    def setUp(self):
+        super(TestEtcd3, self).setUp()
+        self.assertRaises(AttributeError, self.kv_cache._build_cache)
+        self.kv_cache._is_ready = True
+        self.etcd3.get_cluster()
+
+    def test_get_cluster(self):
+        self.assertIsInstance(self.etcd3.get_cluster(), Cluster)
+        self.client._kv_cache = None
+        with patch.object(urllib3.PoolManager, 'urlopen') as mock_urlopen:
+            mock_urlopen.return_value = MockResponse()
+            mock_urlopen.return_value.content = json.dumps({
+                "header": {"revision": "1"},
+                "kvs": [
+                    {"key": base64_encode('/patroni/test/status'),
+                     "value": base64_encode('{"optime":1234567,"slots":{"ls":12345}}'), "mod_revision": '1'}
+                ]
+            })
+            self.assertIsInstance(self.etcd3.get_cluster(), Cluster)
+            mock_urlopen.return_value.content = json.dumps({
+                "header": {"revision": "1"},
+                "kvs": [
+                    {"key": base64_encode('/patroni/test/status'), "value": base64_encode('{'), "mod_revision": '1'}
+                ]
+            })
+            self.assertIsInstance(self.etcd3.get_cluster(), Cluster)
+            mock_urlopen.side_effect = UnsupportedEtcdVersion('')
+            self.assertRaises(UnsupportedEtcdVersion, self.etcd3.get_cluster)
+            mock_urlopen.side_effect = SleepException()
+            self.assertRaises(Etcd3Error, self.etcd3.get_cluster)
+
+    def test_touch_member(self):
+        self.etcd3.touch_member({})
+        self.etcd3._lease = 'bla'
+        self.etcd3.touch_member({})
+        with patch.object(PatroniEtcd3Client, 'lease_grant', Mock(side_effect=Etcd3ClientError)):
+            self.etcd3.touch_member({})
+
+    def test__update_leader(self):
+        self.etcd3._lease = None
+        self.etcd3.update_leader('123')
+        self.etcd3.update_leader('124')
+
+    def test_attempt_to_acquire_leader(self):
+        self.etcd3._lease = None
+        self.assertFalse(self.etcd3.attempt_to_acquire_leader())
+
+    def test_set_ttl(self):
+        self.etcd3.set_ttl(20)
+
+    @patch.object(PatroniEtcd3Client, 'lease_keepalive', Mock(return_value=False))
+    def test_refresh_lease(self):
+        self.etcd3._last_lease_refresh = 0
+        self.etcd3.refresh_lease()
+
+    @patch('time.sleep', Mock(side_effect=SleepException))
+    @patch.object(PatroniEtcd3Client, 'lease_keepalive', Mock(return_value=False))
+    @patch.object(PatroniEtcd3Client, 'lease_grant', Mock(side_effect=Etcd3ClientError))
+    def test_create_lease(self):
+        self.etcd3._lease = None
+        self.etcd3._last_lease_refresh = 0
+        self.assertRaises(SleepException, self.etcd3.create_lease)
+
+    def test_set_failover_value(self):
+        self.etcd3.set_failover_value('', 1)
+
+    def test_set_config_value(self):
+        self.etcd3.set_config_value('')
+
+    def test_initialize(self):
+        self.etcd3.initialize()
+
+    def test_cancel_initialization(self):
+        self.etcd3.cancel_initialization()
+
+    def test_delete_leader(self):
+        self.etcd3.delete_leader()
+
+    def test_delete_cluster(self):
+        self.etcd3.delete_cluster()
+
+    def test_set_history_value(self):
+        self.etcd3.set_history_value('')
+
+    def test_set_sync_state_value(self):
+        self.etcd3.set_sync_state_value('')
+
+    def test_delete_sync_state(self):
+        self.etcd3.delete_sync_state()
+
+    def test_watch(self):
+        self.etcd3.set_ttl(10)
+        self.etcd3.watch(None, 0)
+        self.etcd3.watch(None, 0)
+
+    def test_set_socket_options(self):
+        with patch('socket.SIO_KEEPALIVE_VALS', 1, create=True):
+            self.etcd3.set_socket_options(Mock(), None)

tests/test_exhibitor.py

@@ -24,7 +24,7 @@ class TestExhibitor(unittest.TestCase):
 
     @patch('urllib3.PoolManager.request', Mock(return_value=urllib3.HTTPResponse(
         status=200, body=b'{"servers":["127.0.0.1","127.0.0.2","127.0.0.3"],"port":2181}')))
-    @patch('patroni.dcs.zookeeper.KazooClient', MockKazooClient)
+    @patch('patroni.dcs.zookeeper.PatroniKazooClient', MockKazooClient)
     def setUp(self):
         self.e = Exhibitor({'hosts': ['localhost', 'exhibitor'], 'port': 8181, 'scope': 'test',
                             'name': 'foo', 'ttl': 30, 'retry_timeout': 10})

tests/test_ha.py

@@ -3,11 +3,11 @@ import etcd
 import os
 import sys
 
-from mock import Mock, MagicMock, PropertyMock, patch
+from mock import Mock, MagicMock, PropertyMock, patch, mock_open
 from patroni.config import Config
 from patroni.dcs import Cluster, ClusterConfig, Failover, Leader, Member, get_dcs, SyncState, TimelineHistory
-from patroni.dcs.etcd import Client
-from patroni.exceptions import DCSError, PostgresConnectionException, PatroniException
+from patroni.dcs.etcd import AbstractEtcdClientWithFailover
+from patroni.exceptions import DCSError, PostgresConnectionException, PatroniFatalException
 from patroni.ha import Ha, _MemberStatus
 from patroni.postgresql import Postgresql
 from patroni.postgresql.bootstrap import Bootstrap
@@ -17,8 +17,9 @@ from patroni.postgresql.rewind import Rewind
 from patroni.postgresql.slots import SlotsHandler
 from patroni.utils import tzutc
 from patroni.watchdog import Watchdog
+from six.moves import builtins
 
-from . import PostgresInit, MockPostmaster, psycopg2_connect, requests_get
+from . import PostgresInit, MockPostmaster, psycopg_connect, requests_get
 from .test_etcd import socket_getaddrinfo, etcd_read, etcd_write
 
 SYSID = '12345678901'
@@ -34,10 +35,10 @@ def false(*args, **kwargs):
 
 def get_cluster(initialize, leader, members, failover, sync, cluster_config=None):
     t = datetime.datetime.now().isoformat()
-    history = TimelineHistory(1, '[[1,67197376,"no recovery target specified","' + t + '"]]',
-                              [(1, 67197376, 'no recovery target specified', t)])
+    history = TimelineHistory(1, '[[1,67197376,"no recovery target specified","' + t + '","foo"]]',
+                              [(1, 67197376, 'no recovery target specified', t, 'foo')])
     cluster_config = cluster_config or ClusterConfig(1, {'check_timeline': True}, 1)
-    return Cluster(initialize, cluster_config, leader, 10, members, failover, sync, history)
+    return Cluster(initialize, cluster_config, leader, 10, members, failover, sync, history, None)
 
 
 def get_cluster_not_initialized_without_leader(cluster_config=None):
@@ -47,7 +48,7 @@ def get_cluster_not_initialized_without_leader(cluster_config=None):
 def get_cluster_initialized_without_leader(leader=False, failover=None, sync=None, cluster_config=None):
     m1 = Member(0, 'leader', 28, {'conn_url': 'postgres://replicator:[email protected]:5435/postgres',
                                   'api_url': 'http://127.0.0.1:8008/patroni', 'xlog_location': 4})
-    leader = Leader(0, 0, m1) if leader else None
+    leader = Leader(0, 0, m1 if leader else Member(0, '', 28, {}))
     m2 = Member(0, 'other', 28, {'conn_url': 'postgres://replicator:[email protected]:5436/postgres',
                                  'api_url': 'http://127.0.0.1:8011/patroni',
                                  'state': 'running',
@@ -65,7 +66,7 @@ def get_cluster_initialized_with_leader(failover=None, sync=None):
 
 def get_cluster_initialized_with_only_leader(failover=None, cluster_config=None):
     leader = get_cluster_initialized_without_leader(leader=True, failover=failover).leader
-    return get_cluster(True, leader, [leader], failover, None, cluster_config)
+    return get_cluster(True, leader, [leader.member], failover, None, cluster_config)
 
 
 def get_standby_cluster_initialized_with_only_leader(failover=None, sync=None):
@@ -79,13 +80,14 @@ def get_standby_cluster_initialized_with_only_leader(failover=None, sync=None):
     )
 
 
-def get_node_status(reachable=True, in_recovery=True, timeline=2,
-                    wal_position=10, nofailover=False, watchdog_failed=False):
+def get_node_status(reachable=True, in_recovery=True, dcs_last_seen=0,
+                    timeline=2, wal_position=10, nofailover=False,
+                    watchdog_failed=False):
     def fetch_node_status(e):
         tags = {}
         if nofailover:
             tags['nofailover'] = True
-        return _MemberStatus(e, reachable, in_recovery, timeline, wal_position, tags, watchdog_failed)
+        return _MemberStatus(e, reachable, in_recovery, dcs_last_seen, timeline, wal_position, tags, watchdog_failed)
     return fetch_node_status
 
 
@@ -151,11 +153,14 @@ def run_async(self, func, args=()):
 @patch.object(Postgresql, 'is_running', Mock(return_value=MockPostmaster()))
 @patch.object(Postgresql, 'is_leader', Mock(return_value=True))
 @patch.object(Postgresql, 'timeline_wal_position', Mock(return_value=(1, 10, 1)))
-@patch.object(Postgresql, '_cluster_info_state_get', Mock(return_value=3))
-@patch.object(Postgresql, 'call_nowait', Mock(return_value=True))
+@patch.object(Postgresql, '_cluster_info_state_get', Mock(return_value=10))
 @patch.object(Postgresql, 'data_directory_empty', Mock(return_value=False))
-@patch.object(Postgresql, 'controldata', Mock(return_value={'Database system identifier': SYSID}))
-@patch.object(SlotsHandler, 'sync_replication_slots', Mock())
+@patch.object(Postgresql, 'controldata', Mock(return_value={
+    'Database system identifier': SYSID,
+    'Database cluster state': 'shut down',
+    'Latest checkpoint location': '0/12345678',
+    "Latest checkpoint's TimeLineID": '2'}))
+@patch.object(SlotsHandler, 'load_replication_slots', Mock(side_effect=Exception))
 @patch.object(ConfigHandler, 'append_pg_hba', Mock())
 @patch.object(ConfigHandler, 'write_pgpass', Mock(return_value={}))
 @patch.object(ConfigHandler, 'write_recovery_conf', Mock())
@@ -163,7 +168,7 @@ def run_async(self, func, args=()):
 @patch.object(Postgresql, 'query', Mock())
 @patch.object(Postgresql, 'checkpoint', Mock())
 @patch.object(CancellableSubprocess, 'call', Mock(return_value=0))
-@patch.object(Postgresql, 'get_local_timeline_lsn_from_replication_connection', Mock(return_value=[2, 10]))
+@patch.object(Postgresql, 'get_replica_timeline', Mock(return_value=2))
 @patch.object(Postgresql, 'get_master_timeline', Mock(return_value=2))
 @patch.object(ConfigHandler, 'restore_configuration_files', Mock())
 @patch.object(etcd.Client, 'write', etcd_write)
@@ -182,7 +187,7 @@ class TestHa(PostgresInit):
     @patch.object(etcd.Client, 'read', etcd_read)
     def setUp(self):
         super(TestHa, self).setUp()
-        with patch.object(Client, 'machines') as mock_machines:
+        with patch.object(AbstractEtcdClientWithFailover, 'machines') as mock_machines:
             mock_machines.__get__ = Mock(return_value=['http://remotehost:2379'])
             self.p.set_state('running')
             self.p.set_role('replica')
@@ -197,8 +202,10 @@ class TestHa(PostgresInit):
 
     def test_update_lock(self):
         self.p.last_operation = Mock(side_effect=PostgresConnectionException(''))
-        self.assertTrue(self.ha.update_lock(True))
+        self.ha.dcs.update_leader = Mock(side_effect=Exception)
+        self.assertFalse(self.ha.update_lock(True))
 
+    @patch.object(Postgresql, 'received_timeline', Mock(return_value=None))
     def test_touch_member(self):
         self.p.timeline_wal_position = Mock(return_value=(0, 1, 0))
         self.p.replica_cached_timeline = Mock(side_effect=Exception)
@@ -245,6 +252,15 @@ class TestHa(PostgresInit):
         self.assertEqual(self.ha.run_cycle(), 'starting as a secondary')
         self.assertEqual(self.ha.run_cycle(), 'failed to start postgres')
 
+    def test_recover_raft(self):
+        self.p.controldata = lambda: {'Database cluster state': 'in recovery', 'Database system identifier': SYSID}
+        self.p.is_running = false
+        self.p.follow = true
+        self.assertEqual(self.ha.run_cycle(), 'starting as a secondary')
+        self.p.is_running = true
+        self.ha.dcs.__class__.__name__ = 'Raft'
+        self.assertEqual(self.ha.run_cycle(), 'started as a secondary')
+
     def test_recover_former_master(self):
         self.p.follow = false
         self.p.is_running = false
@@ -254,18 +270,36 @@ class TestHa(PostgresInit):
         self.ha.cluster = get_cluster_initialized_with_leader()
         self.assertEqual(self.ha.run_cycle(), 'starting as readonly because i had the session lock')
 
-    @patch.object(Postgresql, 'fix_cluster_state', Mock())
+    @patch.object(Rewind, 'ensure_clean_shutdown', Mock())
     def test_crash_recovery(self):
+        self.ha.has_lock = true
         self.p.is_running = false
         self.p.controldata = lambda: {'Database cluster state': 'in production', 'Database system identifier': SYSID}
         self.assertEqual(self.ha.run_cycle(), 'doing crash recovery in a single user mode')
+        with patch('patroni.async_executor.AsyncExecutor.busy', PropertyMock(return_value=True)),\
+                patch.object(Ha, 'check_timeline', Mock(return_value=False)):
+            self.ha._async_executor.schedule('doing crash recovery in a single user mode')
+            self.ha.state_handler.cancellable._process = Mock()
+            self.ha._crash_recovery_started -= 600
+            self.ha.patroni.config.set_dynamic_configuration({'maximum_lag_on_failover': 10})
+            self.assertEqual(self.ha.run_cycle(), 'terminated crash recovery because of startup timeout')
 
     @patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=True))
     @patch.object(Rewind, 'can_rewind', PropertyMock(return_value=True))
     def test_recover_with_rewind(self):
         self.p.is_running = false
         self.ha.cluster = get_cluster_initialized_with_leader()
-        self.assertEqual(self.ha.run_cycle(), 'running pg_rewind from leader')
+        self.ha.cluster.leader.member.data.update(version='2.0.2', role='master')
+        self.ha._rewind.pg_rewind = true
+        self.ha._rewind.check_leader_is_not_in_recovery = true
+        with patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=True)):
+            self.assertEqual(self.ha.run_cycle(), 'running pg_rewind from leader')
+        with patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=False)):
+            self.p.follow = true
+            self.assertEqual(self.ha.run_cycle(), 'starting as a secondary')
+            self.p.is_running = true
+            self.ha.follow = Mock(return_value='fake')
+            self.assertEqual(self.ha.run_cycle(), 'fake')
 
     @patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=True))
     @patch.object(Bootstrap, 'create_replica', Mock(return_value=1))
@@ -287,9 +321,9 @@ class TestHa(PostgresInit):
         self.p.is_healthy = true
         self.ha.has_lock = true
         self.p.controldata = lambda: {'Database cluster state': 'in production', 'Database system identifier': SYSID}
-        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader because i had the session lock')
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader because I had the session lock')
 
-    @patch('psycopg2.connect', psycopg2_connect)
+    @patch('patroni.psycopg.connect', psycopg_connect)
     def test_acquire_lock_as_master(self):
         self.assertEqual(self.ha.run_cycle(), 'acquired session lock as a leader')
 
@@ -298,12 +332,25 @@ class TestHa(PostgresInit):
         self.p.is_leader = false
         self.assertEqual(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
 
+    def test_promotion_cancelled_after_pre_promote_failed(self):
+        self.p.is_leader = false
+        self.p._pre_promote = false
+        self.ha._is_healthiest_node = true
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader by acquiring session lock')
+        self.assertEqual(self.ha.run_cycle(), 'Promotion cancelled because the pre-promote script failed')
+        self.assertEqual(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
+
+    def test_lost_leader_lock_during_promote(self):
+        with patch('patroni.async_executor.AsyncExecutor.busy', PropertyMock(return_value=True)):
+            self.ha._async_executor.schedule('promote')
+            self.assertEqual(self.ha.run_cycle(), 'lost leader before promote')
+
     def test_long_promote(self):
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
         self.p.is_leader = false
         self.p.set_role('master')
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
 
     def test_demote_after_failing_to_obtain_lock(self):
         self.ha.acquire_lock = false
@@ -328,7 +375,7 @@ class TestHa(PostgresInit):
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
         self.p.is_leader = false
-        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader because i had the session lock')
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to leader because I had the session lock')
 
     def test_promote_without_watchdog(self):
         self.ha.cluster.is_unlocked = false
@@ -343,35 +390,45 @@ class TestHa(PostgresInit):
         self.ha.cluster = get_cluster_initialized_with_leader()
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
 
     def test_demote_because_not_having_lock(self):
         self.ha.cluster.is_unlocked = false
         with patch.object(Watchdog, 'is_running', PropertyMock(return_value=True)):
-            self.assertEqual(self.ha.run_cycle(), 'demoting self because i do not have the lock and i was a leader')
+            self.assertEqual(self.ha.run_cycle(), 'demoting self because I do not have the lock and I was a leader')
 
     def test_demote_because_update_lock_failed(self):
         self.ha.cluster.is_unlocked = false
         self.ha.has_lock = true
         self.ha.update_lock = false
         self.assertEqual(self.ha.run_cycle(), 'demoted self because failed to update leader lock in DCS')
+        with patch.object(Ha, '_get_node_to_follow', Mock(side_effect=DCSError('foo'))):
+            self.assertEqual(self.ha.run_cycle(), 'demoted self because failed to update leader lock in DCS')
         self.p.is_leader = false
         self.assertEqual(self.ha.run_cycle(), 'not promoting because failed to update leader lock in DCS')
 
+    @patch.object(Postgresql, 'major_version', PropertyMock(return_value=130000))
     def test_follow(self):
         self.ha.cluster.is_unlocked = false
         self.p.is_leader = false
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), a secondary, and following a leader ()')
         self.ha.patroni.replicatefrom = "foo"
         self.p.config.check_recovery_conf = Mock(return_value=(True, False))
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
+        self.ha.cluster.config.data.update({'slots': {'l': {'database': 'a', 'plugin': 'b'}}})
+        self.ha.cluster.members[1].data['tags']['replicatefrom'] = 'postgresql0'
+        self.ha.patroni.nofailover = True
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), a secondary, and following a leader ()')
+        del self.ha.cluster.config.data['slots']
+        self.ha.cluster.config.data.update({'postgresql': {'use_slots': False}})
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), a secondary, and following a leader ()')
+        del self.ha.cluster.config.data['postgresql']['use_slots']
 
     def test_follow_in_pause(self):
         self.ha.cluster.is_unlocked = false
         self.ha.is_paused = true
         self.assertEqual(self.ha.run_cycle(), 'PAUSE: continue to run as master without lock')
         self.p.is_leader = false
-        self.assertEqual(self.ha.run_cycle(), 'PAUSE: no action')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: no action. I am (postgresql0)')
 
     @patch.object(Rewind, 'rewind_or_reinitialize_needed_and_possible', Mock(return_value=True))
     @patch.object(Rewind, 'can_rewind', PropertyMock(return_value=True))
@@ -403,6 +460,8 @@ class TestHa(PostgresInit):
         self.ha.cluster = get_cluster_not_initialized_without_leader()
         self.assertEqual(self.ha.bootstrap(), 'failed to acquire initialize lock')
 
+    @patch('patroni.psycopg.connect', psycopg_connect)
+    @patch.object(Postgresql, 'connection', Mock(return_value=None))
     def test_bootstrap_initialized_new_cluster(self):
         self.ha.cluster = get_cluster_not_initialized_without_leader()
         self.e.initialize = true
@@ -418,8 +477,10 @@ class TestHa(PostgresInit):
         self.e.initialize = true
         self.ha.bootstrap()
         self.p.is_running = false
-        self.assertRaises(PatroniException, self.ha.post_bootstrap)
+        self.assertRaises(PatroniFatalException, self.ha.post_bootstrap)
 
+    @patch('patroni.psycopg.connect', psycopg_connect)
+    @patch.object(Postgresql, 'connection', Mock(return_value=None))
     def test_bootstrap_release_initialize_key_on_watchdog_failure(self):
         self.ha.cluster = get_cluster_not_initialized_without_leader()
         self.e.initialize = true
@@ -428,9 +489,9 @@ class TestHa(PostgresInit):
         self.p.is_leader = true
         with patch.object(Watchdog, 'activate', Mock(return_value=False)):
             self.assertEqual(self.ha.post_bootstrap(), 'running post_bootstrap')
-            self.assertRaises(PatroniException, self.ha.post_bootstrap)
+            self.assertRaises(PatroniFatalException, self.ha.post_bootstrap)
 
-    @patch('psycopg2.connect', psycopg2_connect)
+    @patch('patroni.psycopg.connect', psycopg_connect)
     def test_reinitialize(self):
         self.assertIsNotNone(self.ha.reinitialize())
 
@@ -475,31 +536,34 @@ class TestHa(PostgresInit):
                     self.assertEqual(self.ha.run_cycle(), 'lost leader lock during restart')
                     mock_terminate.assert_called()
 
+            self.ha.is_paused = true
+            self.assertEqual(self.ha.run_cycle(), 'PAUSE: restart in progress')
+
     def test_manual_failover_from_leader(self):
         self.ha.fetch_node_status = get_node_status()
         self.ha.has_lock = true
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', '', None))
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, '', self.p.name, None))
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, '', 'blabla', None))
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
         f = Failover(0, self.p.name, '', None)
         self.ha.cluster = get_cluster_initialized_with_leader(f)
         self.assertEqual(self.ha.run_cycle(), 'manual failover: demoting myself')
         self.ha._rewind.rewind_or_reinitialize_needed_and_possible = true
         self.assertEqual(self.ha.run_cycle(), 'manual failover: demoting myself')
         self.ha.fetch_node_status = get_node_status(nofailover=True)
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
         self.ha.fetch_node_status = get_node_status(watchdog_failed=True)
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
         self.ha.fetch_node_status = get_node_status(timeline=1)
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
         self.ha.fetch_node_status = get_node_status(wal_position=1)
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
         # manual failover from the previous leader to us won't happen if we hold the nofailover flag
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, None))
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
 
         # Failover scheduled time must include timezone
         scheduled = datetime.datetime.now()
@@ -508,28 +572,28 @@ class TestHa(PostgresInit):
 
         scheduled = datetime.datetime.utcnow().replace(tzinfo=tzutc)
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action. I am (postgresql0), the leader with the lock', self.ha.run_cycle())
 
         scheduled = scheduled + datetime.timedelta(seconds=30)
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action. I am (postgresql0), the leader with the lock', self.ha.run_cycle())
 
         scheduled = scheduled + datetime.timedelta(seconds=-600)
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action. I am (postgresql0), the leader with the lock', self.ha.run_cycle())
 
         scheduled = None
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action. I am (postgresql0), the leader with the lock', self.ha.run_cycle())
 
     def test_manual_failover_from_leader_in_pause(self):
         self.ha.has_lock = true
         self.ha.is_paused = true
         scheduled = datetime.datetime.now()
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, 'blabla', self.p.name, scheduled))
-        self.assertEqual('PAUSE: no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('PAUSE: no action. I am (postgresql0), the leader with the lock', self.ha.run_cycle())
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, self.p.name, '', None))
-        self.assertEqual('PAUSE: no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('PAUSE: no action. I am (postgresql0), the leader with the lock', self.ha.run_cycle())
 
     def test_manual_failover_from_leader_in_synchronous_mode(self):
         self.p.is_leader = true
@@ -538,7 +602,7 @@ class TestHa(PostgresInit):
         self.ha.is_failover_possible = false
         self.ha.process_sync_replication = Mock()
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, self.p.name, 'a', None), (self.p.name, None))
-        self.assertEqual('no action.  i am the leader with the lock', self.ha.run_cycle())
+        self.assertEqual('no action. I am (postgresql0), the leader with the lock', self.ha.run_cycle())
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, self.p.name, 'a', None), (self.p.name, 'a'))
         self.ha.is_failover_possible = true
         self.assertEqual('manual failover: demoting myself', self.ha.run_cycle())
@@ -566,6 +630,11 @@ class TestHa(PostgresInit):
         # same as previous, but set the current member to nofailover. In no case it should be elected as a leader
         self.ha.patroni.nofailover = True
         self.assertEqual(self.ha.run_cycle(), 'following a different leader because I am not allowed to promote')
+        # in sync mode only the sync node is allowed to take over
+        self.ha.cluster = get_cluster_initialized_without_leader(failover=Failover(0, 'leader', 'other', None))
+        self.ha.patroni.nofailover = False
+        self.ha.is_synchronous_mode = true
+        self.assertEqual(self.ha.run_cycle(), 'following a different leader because i am not the healthiest node')
 
     def test_manual_failover_process_no_leader_in_pause(self):
         self.ha.is_paused = true
@@ -605,7 +674,7 @@ class TestHa(PostgresInit):
         # in synchronous_mode consider itself healthy if the former leader is accessible in read-only and ahead of us
         with patch.object(Ha, 'is_synchronous_mode', Mock(return_value=True)):
             self.assertTrue(self.ha._is_healthiest_node(self.ha.old_cluster.members))
-        with patch('patroni.postgresql.Postgresql.timeline_wal_position', return_value=(1, 1, 1)):
+        with patch('patroni.postgresql.Postgresql.last_operation', return_value=1):
             self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
         with patch('patroni.postgresql.Postgresql.replica_cached_timeline', return_value=1):
             self.assertFalse(self.ha._is_healthiest_node(self.ha.old_cluster.members))
@@ -644,7 +713,7 @@ class TestHa(PostgresInit):
 
     def test_evaluate_scheduled_restart(self):
         self.p.postmaster_start_time = Mock(return_value=str(postmaster_start_time))
-        # restart already in progres
+        # restart already in progress
         with patch('patroni.async_executor.AsyncExecutor.busy', PropertyMock(return_value=True)):
             self.assertIsNone(self.ha.evaluate_scheduled_restart())
         # restart while the postmaster has been already restarted, fails
@@ -690,19 +759,26 @@ class TestHa(PostgresInit):
         self.ha.cluster = get_cluster_initialized_with_leader(Failover(0, '', self.p.name, None))
         self.assertEqual(self.ha.run_cycle(), 'PAUSE: waiting to become master after promote...')
 
+    @patch('patroni.postgresql.mtime', Mock(return_value=1588316884))
+    @patch.object(builtins, 'open', mock_open(read_data='1\t0/40159C0\tno recovery target specified\n'))
     def test_process_healthy_standby_cluster_as_standby_leader(self):
         self.p.is_leader = false
         self.p.name = 'leader'
         self.ha.cluster = get_standby_cluster_initialized_with_only_leader()
         self.p.config.check_recovery_conf = Mock(return_value=(False, False))
+        self.ha._leader_timeline = 1
+        self.assertEqual(self.ha.run_cycle(), 'promoted self to a standby leader because i had the session lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (leader), the standby leader with the lock')
+        self.p.set_role('replica')
+        self.p.config.check_recovery_conf = Mock(return_value=(True, False))
         self.assertEqual(self.ha.run_cycle(), 'promoted self to a standby leader because i had the session lock')
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the standby leader with the lock')
 
     def test_process_healthy_standby_cluster_as_cascade_replica(self):
         self.p.is_leader = false
         self.p.name = 'replica'
         self.ha.cluster = get_standby_cluster_initialized_with_only_leader()
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a standby leader')
+        self.assertEqual(self.ha.run_cycle(),
+                         'no action. I am (replica), a secondary, and following a standby leader (leader)')
         with patch.object(Leader, 'conn_url', PropertyMock(return_value='')):
             self.assertEqual(self.ha.run_cycle(), 'continue following the old known standby leader')
 
@@ -795,7 +871,8 @@ class TestHa(PostgresInit):
 
         self.ha.has_lock = false
         self.p.is_leader = false
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am a secondary and i am following a leader')
+        self.assertEqual(self.ha.run_cycle(),
+                         'no action. I am (postgresql0), a secondary, and following a leader (leader)')
         check_calls([(update_lock, False), (demote, False)])
 
     def test_manual_failover_while_starting(self):
@@ -846,7 +923,7 @@ class TestHa(PostgresInit):
         with patch.object(self.ha.dcs, 'delete_sync_state') as mock_delete_sync:
             self.ha.run_cycle()
             mock_delete_sync.assert_called_once()
-            mock_set_sync.assert_called_once_with(None)
+            mock_set_sync.assert_called_once_with([])
 
         mock_set_sync.reset_mock()
         # Test sync key not touched when not there
@@ -854,14 +931,14 @@ class TestHa(PostgresInit):
         with patch.object(self.ha.dcs, 'delete_sync_state') as mock_delete_sync:
             self.ha.run_cycle()
             mock_delete_sync.assert_not_called()
-            mock_set_sync.assert_called_once_with(None)
+            mock_set_sync.assert_called_once_with([])
 
         mock_set_sync.reset_mock()
 
         self.ha.is_synchronous_mode = true
 
         # Test sync standby not touched when picking the same node
-        self.p.pick_synchronous_standby = Mock(return_value=('other', True))
+        self.p.pick_synchronous_standby = Mock(return_value=(['other'], ['other']))
         self.ha.cluster = get_cluster_initialized_with_leader(sync=('leader', 'other'))
         self.ha.run_cycle()
         mock_set_sync.assert_not_called()
@@ -869,10 +946,17 @@ class TestHa(PostgresInit):
         mock_set_sync.reset_mock()
 
         # Test sync standby is replaced when switching standbys
-        self.p.pick_synchronous_standby = Mock(return_value=('other2', False))
+        self.p.pick_synchronous_standby = Mock(return_value=(['other2'], []))
         self.ha.dcs.write_sync_state = Mock(return_value=True)
         self.ha.run_cycle()
-        mock_set_sync.assert_called_once_with('other2')
+        mock_set_sync.assert_called_once_with(['other2'])
+
+        # Test sync standby is replaced when new standby is joined
+        self.p.pick_synchronous_standby = Mock(return_value=(['other2', 'other3'], ['other2']))
+        self.ha.dcs.write_sync_state = Mock(return_value=True)
+        self.ha.run_cycle()
+        self.assertEqual(mock_set_sync.call_args_list[0][0], (['other2'],))
+        self.assertEqual(mock_set_sync.call_args_list[1][0], (['other2', 'other3'],))
 
         mock_set_sync.reset_mock()
         # Test sync standby is not disabled when updating dcs fails
@@ -885,7 +969,7 @@ class TestHa(PostgresInit):
         self.ha.dcs.write_sync_state = Mock(return_value=True)
         self.ha.dcs.get_cluster = Mock(return_value=get_cluster_initialized_with_leader(sync=('leader', 'other')))
         # self.ha.cluster = get_cluster_initialized_with_leader(sync=('leader', 'other'))
-        self.p.pick_synchronous_standby = Mock(return_value=('other2', True))
+        self.p.pick_synchronous_standby = Mock(return_value=(['other2'], ['other2']))
         self.ha.run_cycle()
         self.ha.dcs.get_cluster.assert_called_once()
         self.assertEqual(self.ha.dcs.write_sync_state.call_count, 2)
@@ -908,9 +992,9 @@ class TestHa(PostgresInit):
         # Test sync set to '*' when synchronous_mode_strict is enabled
         mock_set_sync.reset_mock()
         self.ha.is_synchronous_mode_strict = true
-        self.p.pick_synchronous_standby = Mock(return_value=(None, False))
+        self.p.pick_synchronous_standby = Mock(return_value=([], []))
         self.ha.run_cycle()
-        mock_set_sync.assert_called_once_with('*')
+        mock_set_sync.assert_called_once_with(['*'])
 
     def test_sync_replication_become_master(self):
         self.ha.is_synchronous_mode = true
@@ -925,7 +1009,7 @@ class TestHa(PostgresInit):
 
         # When we just became master nobody is sync
         self.assertEqual(self.ha.enforce_master_role('msg', 'promote msg'), 'promote msg')
-        mock_set_sync.assert_called_once_with(None)
+        mock_set_sync.assert_called_once_with([])
         mock_write_sync.assert_called_once_with('leader', None, index=0)
 
         mock_set_sync.reset_mock()
@@ -1007,11 +1091,13 @@ class TestHa(PostgresInit):
         self.ha._disable_sync = False
         self.assertEqual(self.ha.get_effective_tags(), {'foo': 'bar'})
 
+    @patch('patroni.postgresql.mtime', Mock(return_value=1588316884))
+    @patch.object(builtins, 'open', Mock(side_effect=Exception))
     def test_restore_cluster_config(self):
         self.ha.cluster.config.data.clear()
         self.ha.has_lock = true
         self.ha.cluster.is_unlocked = false
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
 
     def test_watch(self):
         self.ha.cluster = get_cluster_initialized_with_leader()
@@ -1022,7 +1108,15 @@ class TestHa(PostgresInit):
 
     def test_shutdown(self):
         self.p.is_running = false
-        self.ha.has_lock = true
+        self.ha.is_leader = true
+
+        def stop(*args, **kwargs):
+            kwargs['on_shutdown'](123)
+
+        self.p.stop = stop
+        self.ha.shutdown()
+
+        self.ha.is_failover_possible = true
         self.ha.shutdown()
 
     @patch('time.sleep', Mock())
@@ -1038,13 +1132,15 @@ class TestHa(PostgresInit):
         # will not say bootstrap from leader as replica can't self elect
         self.assertEqual(self.ha.run_cycle(), "trying to bootstrap from replica 'other'")
 
-    @patch('psycopg2.connect', psycopg2_connect)
+    @patch('patroni.postgresql.mtime', Mock(return_value=1588316884))
+    @patch.object(builtins, 'open', mock_open(read_data=('1\t0/40159C0\tno recovery target specified\n\n'
+                                                         '2\t1/40159C0\tno recovery target specified\n')))
     def test_update_cluster_history(self):
         self.ha.has_lock = true
         self.ha.cluster.is_unlocked = false
         for tl in (1, 3):
             self.p.get_master_timeline = Mock(return_value=tl)
-            self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+            self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
 
     @patch('sys.exit', return_value=1)
     def test_abort_join(self, exit_mock):
@@ -1057,15 +1153,59 @@ class TestHa(PostgresInit):
         self.ha.has_lock = true
         self.ha.cluster.is_unlocked = false
         self.ha.is_paused = true
-        self.assertEqual(self.ha.run_cycle(), 'PAUSE: no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: no action. I am (postgresql0), the leader with the lock')
         self.ha.is_paused = false
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (postgresql0), the leader with the lock')
 
-    @patch('psycopg2.connect', psycopg2_connect)
+    @patch('patroni.psycopg.connect', psycopg_connect)
     def test_permanent_logical_slots_after_promote(self):
         config = ClusterConfig(1, {'slots': {'l': {'database': 'postgres', 'plugin': 'test_decoding'}}}, 1)
+        self.p.name = 'other'
         self.ha.cluster = get_cluster_initialized_without_leader(cluster_config=config)
         self.assertEqual(self.ha.run_cycle(), 'acquired session lock as a leader')
         self.ha.cluster = get_cluster_initialized_without_leader(leader=True, cluster_config=config)
         self.ha.has_lock = true
-        self.assertEqual(self.ha.run_cycle(), 'no action.  i am the leader with the lock')
+        self.assertEqual(self.ha.run_cycle(), 'no action. I am (other), the leader with the lock')
+
+    @patch.object(Cluster, 'has_member', true)
+    def test_run_cycle(self):
+        self.ha.dcs.touch_member = Mock(side_effect=DCSError('foo'))
+        self.assertEqual(self.ha.run_cycle(), 'Unexpected exception raised, please report it as a BUG')
+        self.ha.dcs.touch_member = Mock(side_effect=PatroniFatalException('foo'))
+        self.assertRaises(PatroniFatalException, self.ha.run_cycle)
+
+    def test_empty_directory_in_pause(self):
+        self.ha.is_paused = true
+        self.p.data_directory_empty = true
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: running with empty data directory')
+        self.assertEqual(self.p.role, 'uninitialized')
+
+    @patch('patroni.ha.Ha.sysid_valid', MagicMock(return_value=True))
+    def test_sysid_no_match_in_pause(self):
+        self.ha.is_paused = true
+        self.p.controldata = lambda: {'Database cluster state': 'in recovery', 'Database system identifier': '123'}
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: continue to run as master without lock')
+
+        self.ha.has_lock = true
+        self.assertEqual(self.ha.run_cycle(), 'PAUSE: released leader key voluntarily due to the system ID mismatch')
+
+    @patch('patroni.psycopg.connect', psycopg_connect)
+    @patch('os.path.exists', Mock(return_value=True))
+    @patch('shutil.rmtree', Mock())
+    @patch('os.makedirs', Mock())
+    @patch('os.open', Mock())
+    @patch('os.fsync', Mock())
+    @patch('os.close', Mock())
+    @patch('os.rename', Mock())
+    @patch('patroni.postgresql.Postgresql.is_starting', Mock(return_value=False))
+    @patch.object(builtins, 'open', mock_open())
+    @patch.object(SlotsHandler, 'sync_replication_slots', Mock(return_value=['foo']))
+    def test_follow_copy(self):
+        self.ha.cluster.is_unlocked = false
+        self.p.is_leader = false
+        self.assertTrue(self.ha.run_cycle().startswith('Copying logical slots'))
+
+    def test_is_failover_possible(self):
+        self.ha.fetch_node_status = Mock(return_value=_MemberStatus(self.ha.cluster.members[0],
+                                                                    True, True, 0, 2, None, {}, False))
+        self.assertFalse(self.ha.is_failover_possible(self.ha.cluster.members))

tests/test_kubernetes.py

@@ -1,18 +1,23 @@
 import json
+import socket
 import time
 import unittest
 
-from mock import Mock, patch
-from patroni.dcs.kubernetes import Kubernetes, KubernetesError, k8s_client, RetryFailedError
+from mock import Mock, mock_open, patch
+from patroni.dcs.kubernetes import k8s_client, k8s_config, K8sConfig, K8sConnectionFailed,\
+        K8sException, K8sObject, Kubernetes, KubernetesError, KubernetesRetriableException,\
+        Retry, RetryFailedError, SERVICE_HOST_ENV_NAME, SERVICE_PORT_ENV_NAME
+from six.moves import builtins
 from threading import Thread
-from . import SleepException
+from . import MockResponse, SleepException
 
 
-def mock_list_namespaced_config_map(self, *args, **kwargs):
+def mock_list_namespaced_config_map(*args, **kwargs):
     metadata = {'resource_version': '1', 'labels': {'f': 'b'}, 'name': 'test-config',
                 'annotations': {'initialize': '123', 'config': '{}'}}
     items = [k8s_client.V1ConfigMap(metadata=k8s_client.V1ObjectMeta(**metadata))]
-    metadata.update({'name': 'test-leader', 'annotations': {'optime': '1234', 'leader': 'p-0', 'ttl': '30s'}})
+    metadata.update({'name': 'test-leader',
+                     'annotations': {'optime': '1234x', 'leader': 'p-0', 'ttl': '30s', 'slots': '{'}})
     items.append(k8s_client.V1ConfigMap(metadata=k8s_client.V1ObjectMeta(**metadata)))
     metadata.update({'name': 'test-failover', 'annotations': {'leader': 'p-0'}})
     items.append(k8s_client.V1ConfigMap(metadata=k8s_client.V1ObjectMeta(**metadata)))
@@ -22,73 +27,179 @@ def mock_list_namespaced_config_map(self, *args, **kwargs):
     return k8s_client.V1ConfigMapList(metadata=metadata, items=items, kind='ConfigMapList')
 
 
-def mock_list_namespaced_pod(self, *args, **kwargs):
-    metadata = k8s_client.V1ObjectMeta(resource_version='1', name='p-0', annotations={'status': '{}'})
-    items = [k8s_client.V1Pod(metadata=metadata)]
+def mock_read_namespaced_endpoints(*args, **kwargs):
+    target_ref = k8s_client.V1ObjectReference(kind='Pod', resource_version='10', name='p-0',
+                                              namespace='default', uid='964dfeae-e79b-4476-8a5a-1920b5c2a69d')
+    address0 = k8s_client.V1EndpointAddress(ip='10.0.0.0', target_ref=target_ref)
+    address1 = k8s_client.V1EndpointAddress(ip='10.0.0.1')
+    port = k8s_client.V1EndpointPort(port=5432, name='postgresql', protocol='TCP')
+    subset = k8s_client.V1EndpointSubset(addresses=[address1, address0], ports=[port])
+    metadata = k8s_client.V1ObjectMeta(resource_version='1', labels={'f': 'b'}, name='test',
+                                       annotations={'optime': '1234', 'leader': 'p-0', 'ttl': '30s'})
+    return k8s_client.V1Endpoints(subsets=[subset], metadata=metadata)
+
+
+def mock_list_namespaced_endpoints(*args, **kwargs):
+    return k8s_client.V1EndpointsList(metadata=k8s_client.V1ObjectMeta(resource_version='1'),
+                                      items=[mock_read_namespaced_endpoints()], kind='V1EndpointsList')
+
+
+def mock_list_namespaced_pod(*args, **kwargs):
+    metadata = k8s_client.V1ObjectMeta(resource_version='1', name='p-0', annotations={'status': '{}'},
+                                       uid='964dfeae-e79b-4476-8a5a-1920b5c2a69d')
+    status = k8s_client.V1PodStatus(pod_ip='10.0.0.0')
+    spec = k8s_client.V1PodSpec(hostname='p-0', node_name='kind-control-plane', containers=[])
+    items = [k8s_client.V1Pod(metadata=metadata, status=status, spec=spec)]
     return k8s_client.V1PodList(items=items, kind='PodList')
 
 
-def mock_config_map(*args, **kwargs):
+def mock_namespaced_kind(*args, **kwargs):
     mock = Mock()
     mock.metadata.resource_version = '2'
     return mock
 
 
-@patch('socket.TCP_KEEPIDLE', 4, create=True)
-@patch('socket.TCP_KEEPINTVL', 5, create=True)
-@patch('socket.TCP_KEEPCNT', 6, create=True)
-@patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map', mock_config_map)
-@patch.object(k8s_client.CoreV1Api, 'create_namespaced_config_map', mock_config_map)
-@patch('kubernetes.client.api_client.ThreadPool', Mock(), create=True)
-@patch.object(Thread, 'start', Mock())
-class TestKubernetes(unittest.TestCase):
+def mock_load_k8s_config(self, *args, **kwargs):
+    self._server = ''
 
+
+class TestK8sConfig(unittest.TestCase):
+
+    def test_load_incluster_config(self):
+        for env in ({}, {SERVICE_HOST_ENV_NAME: '', SERVICE_PORT_ENV_NAME: ''}):
+            with patch('os.environ', env):
+                self.assertRaises(k8s_config.ConfigException, k8s_config.load_incluster_config)
+
+        with patch('os.environ', {SERVICE_HOST_ENV_NAME: 'a', SERVICE_PORT_ENV_NAME: '1'}),\
+                patch('os.path.isfile', Mock(side_effect=[False, True, True, False, True, True, True, True])),\
+                patch.object(builtins, 'open', Mock(side_effect=[
+                    mock_open()(), mock_open(read_data='a')(), mock_open(read_data='a')(),
+                    mock_open()(), mock_open(read_data='a')(), mock_open(read_data='a')()])):
+            for _ in range(0, 4):
+                self.assertRaises(k8s_config.ConfigException, k8s_config.load_incluster_config)
+            k8s_config.load_incluster_config()
+            self.assertEqual(k8s_config.server, 'https://a:1')
+
+    def test_load_kube_config(self):
+        config = {
+            "current-context": "local",
+            "contexts": [{"name": "local", "context": {"user": "local", "cluster": "local"}}],
+            "clusters": [{"name": "local", "cluster": {"server": "https://a:1/", "certificate-authority": "a"}}],
+            "users": [{"name": "local", "user": {"username": "a", "password": "b", "client-certificate": "c"}}]
+        }
+        with patch.object(builtins, 'open', mock_open(read_data=json.dumps(config))):
+            k8s_config.load_kube_config()
+            self.assertEqual(k8s_config.server, 'https://a:1')
+            self.assertEqual(k8s_config.pool_config, {'ca_certs': 'a', 'cert_file': 'c', 'cert_reqs': 'CERT_REQUIRED',
+                                                      'maxsize': 10, 'num_pools': 10})
+
+        config["users"][0]["user"]["token"] = "token"
+        with patch.object(builtins, 'open', mock_open(read_data=json.dumps(config))):
+            k8s_config.load_kube_config()
+            self.assertEqual(k8s_config.headers.get('authorization'), 'Bearer token')
+
+
+@patch('urllib3.PoolManager.request')
+class TestApiClient(unittest.TestCase):
+
+    @patch.object(K8sConfig, '_server', '', create=True)
+    @patch('urllib3.PoolManager.request', Mock())
+    def setUp(self):
+        self.a = k8s_client.ApiClient(True)
+        self.mock_get_ep = MockResponse()
+        self.mock_get_ep.content = '{"subsets":[{"ports":[{"name":"https","protocol":"TCP","port":443}],' +\
+                                   '"addresses":[{"ip":"127.0.0.1"},{"ip":"127.0.0.2"}]}]}'
+
+    def test__do_http_request(self, mock_request):
+        mock_request.side_effect = [self.mock_get_ep] + [socket.timeout]
+        self.assertRaises(K8sException, self.a.call_api, 'GET', 'f')
+
+    @patch('time.sleep', Mock())
+    def test_request(self, mock_request):
+        retry = Retry(deadline=10, max_delay=1, max_tries=1, retry_exceptions=KubernetesRetriableException)
+        mock_request.side_effect = [self.mock_get_ep] + 3 * [socket.timeout] + [k8s_client.rest.ApiException(500, '')]
+        self.assertRaises(k8s_client.rest.ApiException, retry, self.a.call_api, 'GET', 'f', _retry=retry)
+        mock_request.side_effect = [self.mock_get_ep, socket.timeout, Mock(), self.mock_get_ep]
+        self.assertRaises(k8s_client.rest.ApiException, retry, self.a.call_api, 'GET', 'f', _retry=retry)
+        retry.deadline = 0.0001
+        mock_request.side_effect = [socket.timeout, socket.timeout, self.mock_get_ep]
+        self.assertRaises(K8sConnectionFailed, retry, self.a.call_api, 'GET', 'f', _retry=retry)
+
+    def test__refresh_api_servers_cache(self, mock_request):
+        mock_request.side_effect = k8s_client.rest.ApiException(403, '')
+        self.a.refresh_api_servers_cache()
+
+
+class TestCoreV1Api(unittest.TestCase):
+
+    @patch('urllib3.PoolManager.request', Mock())
+    @patch.object(K8sConfig, '_server', '', create=True)
+    def setUp(self):
+        self.a = k8s_client.CoreV1Api()
+        self.a._api_client.pool_manager.request = Mock(return_value=MockResponse())
+
+    def test_create_namespaced_service(self):
+        self.assertEqual(str(self.a.create_namespaced_service('default', {}, _request_timeout=2)), '{}')
+
+    def test_list_namespaced_endpoints(self):
+        self.a._api_client.pool_manager.request.return_value.content = '{"items": [1,2,3]}'
+        self.assertIsInstance(self.a.list_namespaced_endpoints('default'), K8sObject)
+
+    def test_patch_namespaced_config_map(self):
+        self.assertEqual(str(self.a.patch_namespaced_config_map('foo', 'default', {}, _request_timeout=(1, 2))), '{}')
+
+    def test_list_namespaced_pod(self):
+        self.a._api_client.pool_manager.request.return_value.status_code = 409
+        self.a._api_client.pool_manager.request.return_value.content = 'foo'
+        try:
+            self.a.list_namespaced_pod('default', label_selector='foo=bar')
+            self.assertFail()
+        except k8s_client.rest.ApiException as e:
+            self.assertTrue('Reason: ' in str(e))
+
+    def test_delete_namespaced_pod(self):
+        self.assertEqual(str(self.a.delete_namespaced_pod('foo', 'default', _request_timeout=(1, 2), body={})), '{}')
+
+
+class BaseTestKubernetes(unittest.TestCase):
+
+    @patch('urllib3.PoolManager.request', Mock())
     @patch('socket.TCP_KEEPIDLE', 4, create=True)
     @patch('socket.TCP_KEEPINTVL', 5, create=True)
     @patch('socket.TCP_KEEPCNT', 6, create=True)
-    @patch('kubernetes.config.load_kube_config', Mock())
-    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map)
-    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_pod', mock_list_namespaced_pod)
-    @patch('kubernetes.client.api_client.ThreadPool', Mock(), create=True)
     @patch.object(Thread, 'start', Mock())
-    def setUp(self):
-        self.k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0',
-                             'loop_wait': 10, 'retry_timeout': 10, 'labels': {'f': 'b'}})
+    @patch.object(K8sConfig, 'load_kube_config', mock_load_k8s_config)
+    @patch.object(K8sConfig, 'load_incluster_config', Mock(side_effect=k8s_config.ConfigException))
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_pod', mock_list_namespaced_pod, create=True)
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map, create=True)
+    def setUp(self, config=None):
+        config = config or {}
+        config.update(ttl=30, scope='test', name='p-0', loop_wait=10,
+                      retry_timeout=10, labels={'f': 'b'}, bypass_api_service=True)
+        self.k = Kubernetes(config)
         self.assertRaises(AttributeError, self.k._pods._build_cache)
         self.k._pods._is_ready = True
-        self.assertRaises(AttributeError, self.k._kinds._build_cache)
+        self.assertRaises(TypeError, self.k._kinds._build_cache)
         self.k._kinds._is_ready = True
         self.k.get_cluster()
 
+
+@patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map', mock_namespaced_kind, create=True)
+class TestKubernetesConfigMaps(BaseTestKubernetes):
+
     @patch('time.time', Mock(side_effect=[1, 10.9, 100]))
     def test__wait_caches(self):
         self.k._pods._is_ready = False
         with self.k._condition:
-            self.assertRaises(RetryFailedError, self.k._wait_caches)
+            self.assertRaises(RetryFailedError, self.k._wait_caches, time.time() + 10)
 
+    @patch('time.time', Mock(return_value=time.time() + 100))
     def test_get_cluster(self):
-        with patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map), \
-                patch.object(k8s_client.CoreV1Api, 'list_namespaced_pod', mock_list_namespaced_pod), \
-                patch('time.time', Mock(return_value=time.time() + 31)):
-            self.k.get_cluster()
+        self.k.get_cluster()
 
         with patch.object(Kubernetes, '_wait_caches', Mock(side_effect=Exception)):
             self.assertRaises(KubernetesError, self.k.get_cluster)
 
-    @patch('kubernetes.config.load_kube_config', Mock())
-    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints', Mock())
-    def test_update_leader(self):
-        k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0', 'loop_wait': 10, 'retry_timeout': 10,
-                        'labels': {'f': 'b'}, 'use_endpoints': True, 'pod_ip': '10.0.0.0'})
-        self.assertIsNotNone(k.update_leader('123'))
-
-    @patch('kubernetes.config.load_kube_config', Mock())
-    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints', Mock())
-    def test_update_leader_with_restricted_access(self):
-        k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0', 'loop_wait': 10, 'retry_timeout': 10,
-                        'labels': {'f': 'b'}, 'use_endpoints': True, 'pod_ip': '10.0.0.0'})
-        self.assertIsNotNone(k.update_leader('123', True))
-
     def test_take_leader(self):
         self.k.take_leader()
         self.k._leader_observed_record['leader'] = 'test'
@@ -96,14 +207,16 @@ class TestKubernetes(unittest.TestCase):
         self.k.take_leader()
 
     def test_manual_failover(self):
-        with patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map', Mock(side_effect=RetryFailedError(''))):
+        with patch.object(k8s_client.CoreV1Api, 'patch_namespaced_config_map',
+                          Mock(side_effect=RetryFailedError('')), create=True):
             self.k.manual_failover('foo', 'bar')
 
     def test_set_config_value(self):
         self.k.set_config_value('{}')
 
-    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_pod', Mock(return_value=True))
-    def test_touch_member(self):
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_pod', create=True)
+    def test_touch_member(self, mock_patch_namespaced_pod):
+        mock_patch_namespaced_pod.return_value.metadata.resource_version = '10'
         self.k.touch_member({'role': 'replica'})
         self.k._name = 'p-1'
         self.k.touch_member({'state': 'running', 'role': 'replica'})
@@ -113,24 +226,16 @@ class TestKubernetes(unittest.TestCase):
         self.k.initialize()
 
     def test_delete_leader(self):
-        self.k.delete_leader()
+        self.k.delete_leader(1)
 
     def test_cancel_initialization(self):
         self.k.cancel_initialization()
 
     @patch.object(k8s_client.CoreV1Api, 'delete_collection_namespaced_config_map',
-                  Mock(side_effect=k8s_client.rest.ApiException(403, '')))
+                  Mock(side_effect=k8s_client.rest.ApiException(403, '')), create=True)
     def test_delete_cluster(self):
         self.k.delete_cluster()
 
-    @patch('kubernetes.config.load_kube_config', Mock())
-    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints',
-                  Mock(side_effect=[k8s_client.rest.ApiException(502, ''), k8s_client.rest.ApiException(500, '')]))
-    def test_delete_sync_state(self):
-        k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0', 'loop_wait': 10, 'retry_timeout': 10,
-                        'labels': {'f': 'b'}, 'use_endpoints': True, 'pod_ip': '10.0.0.0'})
-        self.assertFalse(k.delete_sync_state())
-
     def test_watch(self):
         self.k.set_ttl(10)
         self.k.watch(None, 0)
@@ -139,33 +244,62 @@ class TestKubernetes(unittest.TestCase):
     def test_set_history_value(self):
         self.k.set_history_value('{}')
 
-    @patch('kubernetes.config.load_kube_config', Mock())
-    @patch('patroni.dcs.kubernetes.ObjectCache', Mock())
-    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_pod', Mock(return_value=True))
-    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints', Mock())
+
+class TestKubernetesEndpoints(BaseTestKubernetes):
+
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_endpoints', mock_list_namespaced_endpoints, create=True)
+    def setUp(self, config=None):
+        super(TestKubernetesEndpoints, self).setUp({'use_endpoints': True, 'pod_ip': '10.0.0.0'})
+
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_endpoints', create=True)
+    def test_update_leader(self, mock_patch_namespaced_endpoints):
+        self.assertIsNotNone(self.k.update_leader('123'))
+        args = mock_patch_namespaced_endpoints.call_args[0]
+        self.assertEqual(args[2].subsets[0].addresses[0].target_ref.resource_version, '10')
+        self.k._kinds._object_cache['test'].subsets[:] = []
+        self.assertIsNotNone(self.k.update_leader('123'))
+        self.k._kinds._object_cache['test'].metadata.annotations['leader'] = 'p-1'
+        self.assertFalse(self.k.update_leader('123'))
+
+    @patch.object(k8s_client.CoreV1Api, 'read_namespaced_endpoints', create=True)
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_endpoints', create=True)
+    def test__update_leader_with_retry(self, mock_patch, mock_read):
+        mock_read.return_value = mock_read_namespaced_endpoints()
+        mock_patch.side_effect = k8s_client.rest.ApiException(502, '')
+        self.assertFalse(self.k.update_leader('123'))
+        mock_patch.side_effect = RetryFailedError('')
+        self.assertFalse(self.k.update_leader('123'))
+        mock_patch.side_effect = k8s_client.rest.ApiException(409, '')
+        with patch('time.time', Mock(side_effect=[0, 100, 200, 0, 0, 0, 0, 100, 200])):
+            self.assertFalse(self.k.update_leader('123'))
+            self.assertFalse(self.k.update_leader('123'))
+        self.assertFalse(self.k.update_leader('123'))
+        mock_patch.side_effect = [k8s_client.rest.ApiException(409, ''), mock_namespaced_kind()]
+        mock_read.return_value.metadata.resource_version = '2'
+        self.assertIsNotNone(self.k._update_leader_with_retry({}, '1', []))
+        mock_patch.side_effect = k8s_client.rest.ApiException(409, '')
+        mock_read.side_effect = Exception
+        self.assertFalse(self.k.update_leader('123'))
+
+    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints',
+                  Mock(side_effect=[k8s_client.rest.ApiException(500, ''),
+                                    k8s_client.rest.ApiException(502, '')]), create=True)
+    def test_delete_sync_state(self):
+        self.assertFalse(self.k.delete_sync_state())
+
+    @patch.object(k8s_client.CoreV1Api, 'patch_namespaced_pod', mock_namespaced_kind, create=True)
+    @patch.object(k8s_client.CoreV1Api, 'create_namespaced_endpoints', mock_namespaced_kind, create=True)
     @patch.object(k8s_client.CoreV1Api, 'create_namespaced_service',
-                  Mock(side_effect=[True, False, k8s_client.rest.ApiException(500, '')]))
+                  Mock(side_effect=[True, False, k8s_client.rest.ApiException(500, '')]), create=True)
     def test__create_config_service(self):
-        k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0', 'loop_wait': 10, 'retry_timeout': 10,
-                        'labels': {'f': 'b'}, 'use_endpoints': True, 'pod_ip': '10.0.0.0'})
-        self.assertIsNotNone(k.patch_or_create_config({'foo': 'bar'}))
-        self.assertIsNotNone(k.patch_or_create_config({'foo': 'bar'}))
-        k.touch_member({'state': 'running', 'role': 'replica'})
+        self.assertIsNotNone(self.k.patch_or_create_config({'foo': 'bar'}))
+        self.assertIsNotNone(self.k.patch_or_create_config({'foo': 'bar'}))
+        self.k.touch_member({'state': 'running', 'role': 'replica'})
 
 
-class TestCacheBuilder(unittest.TestCase):
+class TestCacheBuilder(BaseTestKubernetes):
 
-    @patch('socket.TCP_KEEPIDLE', 4, create=True)
-    @patch('socket.TCP_KEEPINTVL', 5, create=True)
-    @patch('socket.TCP_KEEPCNT', 6, create=True)
-    @patch('kubernetes.config.load_kube_config', Mock())
-    @patch('kubernetes.client.api_client.ThreadPool', Mock(), create=True)
-    @patch.object(Thread, 'start', Mock())
-    def setUp(self):
-        self.k = Kubernetes({'ttl': 30, 'scope': 'test', 'name': 'p-0',
-                             'loop_wait': 10, 'retry_timeout': 10, 'labels': {'f': 'b'}})
-
-    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map)
+    @patch.object(k8s_client.CoreV1Api, 'list_namespaced_config_map', mock_list_namespaced_config_map, create=True)
     @patch('patroni.dcs.kubernetes.ObjectCache._watch')
     def test__build_cache(self, mock_response):
         mock_response.return_value.read_chunked.return_value = [json.dumps(
@@ -176,7 +310,7 @@ class TestCacheBuilder(unittest.TestCase):
                 'name': self.k.config_path, 'resourceVersion': '3'}}}
         ) + '\n' + json.dumps(
             {'type': 'MDIFIED', 'object': {'metadata': {'name': self.k.config_path}}}
-        ) + '\n' + json.dumps({'object': {'code': 410}}) + '\n').encode('utf-8')]
+        ) + '\n').encode('utf-8'), b'{"object":{', b'"code":410}}\n']
         self.k._kinds._build_cache()
 
     @patch('patroni.dcs.kubernetes.logger.error', Mock(side_effect=SleepException))

tests/test_log.py

@@ -43,7 +43,8 @@ class TestPatroniLogger(unittest.TestCase):
         _LOG.exception('test')
         logger.start()
 
-        with patch.object(logging.Handler, 'format', Mock(side_effect=Exception)):
+        with patch.object(logging.Handler, 'format', Mock(side_effect=Exception)),\
+                patch('_pytest.logging.LogCaptureHandler.emit', Mock()):
             logging.error('test')
 
         self.assertEqual(logger.log_handler.maxBytes, config['log']['file_size'])
@@ -62,3 +63,12 @@ class TestPatroniLogger(unittest.TestCase):
             self.assertRaises(Exception, logger.shutdown)
         self.assertLessEqual(logger.queue_size, 2)  # "Failed to close the old log handler" could be still in the queue
         self.assertEqual(logger.records_lost, 0)
+
+    def test_interceptor(self):
+        logger = PatroniLogger()
+        logger.reload_config({'level': 'INFO'})
+        logger.start()
+        _LOG.info('Lock owner: ')
+        _LOG.info('blabla')
+        logger.shutdown()
+        self.assertEqual(logger.records_lost, 0)

tests/test_patroni.py

@@ -9,19 +9,27 @@ import patroni.config as config
 from mock import Mock, PropertyMock, patch
 from patroni.api import RestApiServer
 from patroni.async_executor import AsyncExecutor
-from patroni.dcs.etcd import Client
+from patroni.dcs.etcd import AbstractEtcdClientWithFailover
 from patroni.exceptions import DCSError
 from patroni.postgresql import Postgresql
 from patroni.postgresql.config import ConfigHandler
-from patroni import Patroni, main as _main, patroni_main, check_psycopg2
+from patroni import Patroni, main as _main, patroni_main, check_psycopg
 from six.moves import BaseHTTPServer, builtins
 from threading import Thread
 
-from . import psycopg2_connect, SleepException
+from . import psycopg_connect, SleepException
 from .test_etcd import etcd_read, etcd_write
 from .test_postgresql import MockPostmaster
 
 
+def mock_import(*args, **kwargs):
+    if args[0] == 'psycopg':
+        raise ImportError
+    ret = Mock()
+    ret.__version__ = '2.5.3.dev1 a b c'
+    return ret
+
+
 class MockFrozenImporter(object):
 
     toc = set(['patroni.dcs.etcd'])
@@ -29,7 +37,7 @@ class MockFrozenImporter(object):
 
 @patch('time.sleep', Mock())
 @patch('subprocess.call', Mock(return_value=0))
-@patch('psycopg2.connect', psycopg2_connect)
+@patch('patroni.psycopg.connect', psycopg_connect)
 @patch.object(ConfigHandler, 'append_pg_hba', Mock())
 @patch.object(ConfigHandler, 'write_postgresql_conf', Mock())
 @patch.object(ConfigHandler, 'write_recovery_conf', Mock())
@@ -53,7 +61,7 @@ class TestPatroni(unittest.TestCase):
     @patch.object(BaseHTTPServer.HTTPServer, '__init__', Mock())
     @patch.object(etcd.Client, 'read', etcd_read)
     @patch.object(Thread, 'start', Mock())
-    @patch.object(Client, 'machines', PropertyMock(return_value=['http://remotehost:2379']))
+    @patch.object(AbstractEtcdClientWithFailover, 'machines', PropertyMock(return_value=['http://remotehost:2379']))
     def setUp(self):
         self._handlers = logging.getLogger().handlers[:]
         RestApiServer._BaseServer__is_shut_down = Mock()
@@ -75,7 +83,7 @@ class TestPatroni(unittest.TestCase):
     @patch('sys.argv', ['patroni.py', 'postgres0.yml'])
     @patch('time.sleep', Mock(side_effect=SleepException))
     @patch.object(etcd.Client, 'delete', Mock())
-    @patch.object(Client, 'machines', PropertyMock(return_value=['http://remotehost:2379']))
+    @patch.object(AbstractEtcdClientWithFailover, 'machines', PropertyMock(return_value=['http://remotehost:2379']))
     @patch.object(Thread, 'join', Mock())
     def test_patroni_patroni_main(self):
         with patch('subprocess.call', Mock(return_value=1)):
@@ -167,7 +175,7 @@ class TestPatroni(unittest.TestCase):
     def test_reload_config(self):
         self.p.reload_config()
         self.p.get_tags = Mock(side_effect=Exception)
-        self.p.reload_config()
+        self.p.reload_config(local=True)
 
     def test_nosync(self):
         self.p.tags['nosync'] = True
@@ -181,8 +189,8 @@ class TestPatroni(unittest.TestCase):
         self.p.ha.shutdown = Mock(side_effect=Exception)
         self.p.shutdown()
 
-    def test_check_psycopg2(self):
+    def test_check_psycopg(self):
         with patch.object(builtins, '__import__', Mock(side_effect=ImportError)):
-            self.assertRaises(SystemExit, check_psycopg2)
-        with patch('psycopg2.__version__', '2.5.3.dev1 a b c'):
-            self.assertRaises(SystemExit, check_psycopg2)
+            self.assertRaises(SystemExit, check_psycopg)
+        with patch.object(builtins, '__import__', mock_import):
+            self.assertRaises(SystemExit, check_psycopg)

tests/test_postgresql.py

@@ -1,23 +1,25 @@
-import mock  # for the mock.call method, importing it without a namespace breaks python3
+import datetime
 import os
 import psutil
-import psycopg2
 import re
 import subprocess
 import time
 
 from mock import Mock, MagicMock, PropertyMock, patch, mock_open
+
+import patroni.psycopg as psycopg
+
 from patroni.async_executor import CriticalTask
-from patroni.dcs import Cluster, ClusterConfig, Member, RemoteMember, SyncState
+from patroni.dcs import Cluster, RemoteMember, SyncState
 from patroni.exceptions import PostgresConnectionException, PatroniException
 from patroni.postgresql import Postgresql, STATE_REJECT, STATE_NO_RESPONSE
+from patroni.postgresql.bootstrap import Bootstrap
 from patroni.postgresql.postmaster import PostmasterProcess
-from patroni.postgresql.slots import SlotsHandler
 from patroni.utils import RetryFailedError
 from six.moves import builtins
 from threading import Thread, current_thread
 
-from . import BaseTestPostgresql, MockCursor, MockPostmaster, psycopg2_connect
+from . import BaseTestPostgresql, MockCursor, MockPostmaster, psycopg_connect
 
 
 mtime_ret = {}
@@ -87,18 +89,17 @@ Data page checksum version:           0
 
 
 @patch('subprocess.call', Mock(return_value=0))
-@patch('psycopg2.connect', psycopg2_connect)
+@patch('patroni.psycopg.connect', psycopg_connect)
 class TestPostgresql(BaseTestPostgresql):
 
     @patch('subprocess.call', Mock(return_value=0))
     @patch('os.rename', Mock())
     @patch('patroni.postgresql.CallbackExecutor', Mock())
-    @patch.object(Postgresql, 'get_major_version', Mock(return_value=120000))
+    @patch.object(Postgresql, 'get_major_version', Mock(return_value=130000))
     @patch.object(Postgresql, 'is_running', Mock(return_value=True))
     def setUp(self):
         super(TestPostgresql, self).setUp()
         self.p.config.write_postgresql_conf()
-        self.p._callback_executor = Mock()
 
     @patch('subprocess.Popen')
     @patch.object(Postgresql, 'wait_for_startup')
@@ -204,6 +205,21 @@ class TestPostgresql(BaseTestPostgresql):
         mock_postmaster.signal_stop.side_effect = [None, True]
         self.assertTrue(self.p.stop(on_safepoint=mock_callback, stop_timeout=30))
 
+    @patch('time.sleep', Mock())
+    @patch.object(Postgresql, 'is_running', MockPostmaster)
+    @patch.object(Postgresql, '_wait_for_connection_close', Mock())
+    @patch.object(Postgresql, 'latest_checkpoint_location', Mock(return_value='7'))
+    def test__do_stop(self):
+        mock_callback = Mock()
+        with patch.object(Postgresql, 'controldata', Mock(return_value={'Database cluster state': 'shut down'})):
+            self.assertTrue(self.p.stop(on_shutdown=mock_callback, stop_timeout=3))
+            mock_callback.assert_called()
+        with patch.object(Postgresql, 'controldata',
+                          Mock(return_value={'Database cluster state': 'shut down in recovery'})):
+            self.assertTrue(self.p.stop(on_shutdown=mock_callback, stop_timeout=3))
+        with patch.object(Postgresql, 'controldata', Mock(return_value={'Database cluster state': 'shutting down'})):
+            self.assertTrue(self.p.stop(on_shutdown=mock_callback, stop_timeout=3))
+
     def test_restart(self):
         self.p.start = Mock(return_value=False)
         self.assertFalse(self.p.restart())
@@ -225,6 +241,7 @@ class TestPostgresql(BaseTestPostgresql):
     @patch('patroni.postgresql.config.mtime', mock_mtime)
     @patch('patroni.postgresql.config.ConfigHandler._get_pg_settings')
     def test_check_recovery_conf(self, mock_get_pg_settings):
+        self.p.call_nowait('on_start')
         mock_get_pg_settings.return_value = {
             'primary_conninfo': ['primary_conninfo', 'foo=', None, 'string', 'postmaster', self.p.config._auto_conf],
             'recovery_min_apply_delay': ['recovery_min_apply_delay', '0', 'ms', 'integer', 'sighup', 'foo']
@@ -250,12 +267,17 @@ class TestPostgresql(BaseTestPostgresql):
             self.p.config.write_recovery_conf({'standby_mode': 'on', 'primary_conninfo': conninfo.copy()})
             self.p.config.write_postgresql_conf()
             self.assertEqual(self.p.config.check_recovery_conf(None), (False, False))
+            with patch.object(Postgresql, 'primary_conninfo', Mock(return_value='host=1')):
+                mock_get_pg_settings.return_value['primary_slot_name'] = [
+                    'primary_slot_name', '', '', 'string', 'postmaster', self.p.config._postgresql_conf]
+                self.assertEqual(self.p.config.check_recovery_conf(None), (True, True))
 
     @patch.object(Postgresql, 'major_version', PropertyMock(return_value=120000))
     @patch.object(Postgresql, 'is_running', MockPostmaster)
     @patch.object(MockPostmaster, 'create_time', Mock(return_value=1234567), create=True)
     @patch('patroni.postgresql.config.ConfigHandler._get_pg_settings')
     def test__read_recovery_params(self, mock_get_pg_settings):
+        self.p.call_nowait('on_start')
         mock_get_pg_settings.return_value = {'primary_conninfo': ['primary_conninfo', '', None, 'string',
                                                                   'postmaster', self.p.config._postgresql_conf]}
         self.p.config.write_recovery_conf({'standby_mode': 'on', 'primary_conninfo': {'password': 'foo'}})
@@ -267,11 +289,12 @@ class TestPostgresql(BaseTestPostgresql):
             self.assertEqual(self.p.config.check_recovery_conf(None), (True, True))
 
     @patch.object(Postgresql, 'major_version', PropertyMock(return_value=100000))
+    @patch.object(Postgresql, 'primary_conninfo', Mock(return_value='host=1'))
     def test__read_recovery_params_pre_v12(self):
-        self.p.config.write_recovery_conf({'standby_mode': 'on', 'primary_conninfo': {'password': 'foo'}})
+        self.p.config.write_recovery_conf({'standby_mode': 'off', 'primary_conninfo': {'password': 'foo'}})
         self.assertEqual(self.p.config.check_recovery_conf(None), (True, True))
         self.assertEqual(self.p.config.check_recovery_conf(None), (True, True))
-        self.p.config.write_recovery_conf({'standby_mode': '\n'})
+        self.p.config.write_recovery_conf({'restore_command': '\n'})
         with patch('patroni.postgresql.config.mtime', mock_mtime):
             self.assertEqual(self.p.config.check_recovery_conf(None), (True, True))
 
@@ -298,29 +321,7 @@ class TestPostgresql(BaseTestPostgresql):
         m = RemoteMember('1', {'restore_command': '2', 'primary_slot_name': 'foo', 'conn_kwargs': {'host': 'bar'}})
         self.p.follow(m)
 
-    @patch.object(Postgresql, 'is_running', Mock(return_value=True))
-    def test_sync_replication_slots(self):
-        self.p.start()
-        config = ClusterConfig(1, {'slots': {'test_3': {'database': 'a', 'plugin': 'b'},
-                                             'A': 0, 'ls': 0, 'b': {'type': 'logical', 'plugin': '1'}}}, 1)
-        cluster = Cluster(True, config, self.leader, 0, [self.me, self.other, self.leadermem], None, None, None)
-        with mock.patch('patroni.postgresql.Postgresql._query', Mock(side_effect=psycopg2.OperationalError)):
-            self.p.slots_handler.sync_replication_slots(cluster)
-        self.p.slots_handler.sync_replication_slots(cluster)
-        with mock.patch('patroni.postgresql.Postgresql.role', new_callable=PropertyMock(return_value='replica')):
-            self.p.slots_handler.sync_replication_slots(cluster)
-        with patch.object(SlotsHandler, 'drop_replication_slot', Mock(return_value=True)),\
-                patch('patroni.dcs.logger.error', new_callable=Mock()) as errorlog_mock:
-            alias1 = Member(0, 'test-3', 28, {'conn_url': 'postgres://replicator:[email protected]:5436/postgres'})
-            alias2 = Member(0, 'test.3', 28, {'conn_url': 'postgres://replicator:[email protected]:5436/postgres'})
-            cluster.members.extend([alias1, alias2])
-            self.p.slots_handler.sync_replication_slots(cluster)
-            self.assertEqual(errorlog_mock.call_count, 5)
-            ca = errorlog_mock.call_args_list[0][0][1]
-            self.assertTrue("test-3" in ca, "non matching {0}".format(ca))
-            self.assertTrue("test.3" in ca, "non matching {0}".format(ca))
-
-    @patch.object(MockCursor, 'execute', Mock(side_effect=psycopg2.OperationalError))
+    @patch.object(MockCursor, 'execute', Mock(side_effect=psycopg.OperationalError))
     def test__query(self):
         self.assertRaises(PostgresConnectionException, self.p._query, 'blabla')
         self.p._state = 'restarting'
@@ -329,14 +330,46 @@ class TestPostgresql(BaseTestPostgresql):
     def test_query(self):
         self.p.query('select 1')
         self.assertRaises(PostgresConnectionException, self.p.query, 'RetryFailedError')
-        self.assertRaises(psycopg2.ProgrammingError, self.p.query, 'blabla')
+        self.assertRaises(psycopg.ProgrammingError, self.p.query, 'blabla')
 
     @patch.object(Postgresql, 'pg_isready', Mock(return_value=STATE_REJECT))
     def test_is_leader(self):
         self.assertTrue(self.p.is_leader())
-        self.p.reset_cluster_info_state()
+        self.p.reset_cluster_info_state(None)
         with patch.object(Postgresql, '_query', Mock(side_effect=RetryFailedError(''))):
-            self.assertRaises(PostgresConnectionException, self.p.is_leader)
+            self.assertFalse(self.p.is_leader())
+
+    @patch.object(Postgresql, 'controldata', Mock(return_value={'Database cluster state': 'shut down',
+                                                                'Latest checkpoint location': '0/1ADBC18',
+                                                                "Latest checkpoint's TimeLineID": '1'}))
+    @patch('subprocess.Popen')
+    def test_latest_checkpoint_location(self, mock_popen):
+        mock_popen.return_value.communicate.return_value = (None, None)
+        self.assertEqual(self.p.latest_checkpoint_location(), '28163096')
+        # 9.3 and 9.4 format
+        mock_popen.return_value.communicate.side_effect = [
+            (b'rmgr: XLOG        len (rec/tot):     72/   104, tx:          0, lsn: 0/01ADBC18, prev 0/01ADBBB8, ' +
+             b'bkp: 0000, desc: checkpoint: redo 0/1ADBC18; tli 1; prev tli 1; fpw true; xid 0/727; oid 16386; multi' +
+             b' 1; offset 0; oldest xid 715 in DB 1; oldest multi 1 in DB 1; oldest running xid 0; shutdown', None),
+            (b'rmgr: Transaction len (rec/tot):     64/    96, tx:        726, lsn: 0/01ADBBB8, prev 0/01ADBB70, ' +
+             b'bkp: 0000, desc: commit: 2021-02-26 11:19:37.900918 CET; inval msgs: catcache 11 catcache 10', None)]
+        self.assertEqual(self.p.latest_checkpoint_location(), '28163096')
+        mock_popen.return_value.communicate.side_effect = [
+            (b'rmgr: XLOG        len (rec/tot):     72/   104, tx:          0, lsn: 0/01ADBC18, prev 0/01ADBBB8, ' +
+             b'bkp: 0000, desc: checkpoint: redo 0/1ADBC18; tli 1; prev tli 1; fpw true; xid 0/727; oid 16386; multi' +
+             b' 1; offset 0; oldest xid 715 in DB 1; oldest multi 1 in DB 1; oldest running xid 0; shutdown', None),
+            (b'rmgr: XLOG        len (rec/tot):      0/    32, tx:          0, lsn: 0/01ADBBB8, prev 0/01ADBBA0, ' +
+             b'bkp: 0000, desc: xlog switch ', None)]
+        self.assertEqual(self.p.latest_checkpoint_location(), '28163000')
+        # 9.5+ format
+        mock_popen.return_value.communicate.side_effect = [
+            (b'rmgr: XLOG        len (rec/tot):    114/   114, tx:          0, lsn: 0/01ADBC18, prev 0/018260F8, ' +
+             b'desc: CHECKPOINT_SHUTDOWN redo 0/1825ED8; tli 1; prev tli 1; fpw true; xid 0:494; oid 16387; multi 1' +
+             b'; offset 0; oldest xid 479 in DB 1; oldest multi 1 in DB 1; oldest/newest commit timestamp xid: 0/0;' +
+             b' oldest running xid 0; shutdown', None),
+            (b'rmgr: XLOG        len (rec/tot):     24/    24, tx:          0, lsn: 0/018260F8, prev 0/01826080, ' +
+             b'desc: SWITCH ', None)]
+        self.assertEqual(self.p.latest_checkpoint_location(), '25321720')
 
     def test_reload(self):
         self.assertTrue(self.p.reload())
@@ -348,10 +381,22 @@ class TestPostgresql(BaseTestPostgresql):
         mock_is_running.return_value = False
         self.assertFalse(self.p.is_healthy())
 
-    def test_promote(self):
+    @patch('psutil.Popen')
+    def test_promote(self, mock_popen):
+        mock_popen.return_value.wait.return_value = 0
+        task = CriticalTask()
+        self.assertTrue(self.p.promote(0, task))
+
         self.p.set_role('replica')
-        self.assertIsNone(self.p.promote(0))
-        self.assertTrue(self.p.promote(0))
+        self.p.config._config['pre_promote'] = 'test'
+        with patch('patroni.postgresql.cancellable.CancellableSubprocess.is_cancelled', PropertyMock(return_value=1)):
+            self.assertFalse(self.p.promote(0, task))
+
+        mock_popen.side_effect = Exception
+        self.assertFalse(self.p.promote(0, task))
+        task.reset()
+        task.cancel()
+        self.assertFalse(self.p.promote(0, task))
 
     def test_timeline_wal_position(self):
         self.assertEqual(self.p.timeline_wal_position(), (1, 2, 1))
@@ -387,11 +432,15 @@ class TestPostgresql(BaseTestPostgresql):
     @patch.object(Postgresql, 'is_running', Mock(return_value=MockPostmaster()))
     def test_is_leader_exception(self):
         self.p.start()
-        self.p.query = Mock(side_effect=psycopg2.OperationalError("not supported"))
+        self.p.query = Mock(side_effect=psycopg.OperationalError("not supported"))
         self.assertTrue(self.p.stop())
 
     @patch('os.rename', Mock())
     @patch('os.path.isdir', Mock(return_value=True))
+    @patch('os.unlink', Mock())
+    @patch('os.symlink', Mock())
+    @patch('patroni.postgresql.Postgresql.pg_wal_realpath', Mock(return_value={'pg_wal': '/mnt/pg_wal'}))
+    @patch('patroni.postgresql.Postgresql.pg_tblspc_realpaths', Mock(return_value={'42': '/mnt/tablespaces/archive'}))
     def test_move_data_directory(self):
         self.p.move_data_directory()
         with patch('os.rename', Mock(side_effect=OSError)):
@@ -405,11 +454,9 @@ class TestPostgresql(BaseTestPostgresql):
 
     def test_remove_data_directory(self):
         def _symlink(src, dst):
-            try:
+            if os.name != 'nt':  # os.symlink under Windows needs admin rights skip it
                 os.symlink(src, dst)
-            except OSError:
-                if os.name == 'nt':  # os.symlink under Windows needs admin rights skip it
-                    pass
+
         os.makedirs(os.path.join(self.p.data_dir, 'foo'))
         _symlink('foo', os.path.join(self.p.data_dir, 'pg_wal'))
         os.makedirs(os.path.join(self.p.data_dir, 'foo_tsp'))
@@ -474,7 +521,8 @@ class TestPostgresql(BaseTestPostgresql):
         parameters = self._PARAMETERS.copy()
         parameters.pop('f.oo')
         parameters['wal_buffers'] = '512'
-        config = {'pg_hba': [''], 'pg_ident': [''], 'use_unix_socket': True, 'authentication': {},
+        config = {'pg_hba': [''], 'pg_ident': [''], 'use_unix_socket': True, 'use_unix_socket_repl': True,
+                  'authentication': {},
                   'retry_timeout': 10, 'listen': '*', 'krbsrvname': 'postgres', 'parameters': parameters}
         self.p.reload_config(config)
         mock_fetchone.side_effect = Exception
@@ -490,6 +538,14 @@ class TestPostgresql(BaseTestPostgresql):
         self.p.reload_config(config)
         self.p.config.resolve_connection_addresses()
 
+    def test_resolve_connection_addresses(self):
+        self.p.config._config['use_unix_socket'] = self.p.config._config['use_unix_socket_repl'] = True
+        self.p.config.resolve_connection_addresses()
+        self.assertEqual(self.p.config.local_replication_address, {'host': '/tmp', 'port': '5432'})
+        self.p.config._server_parameters.pop('unix_socket_directories')
+        self.p.config.resolve_connection_addresses()
+        self.assertEqual(self.p.config._local_address, {'port': '5432'})
+
     @patch.object(Postgresql, '_version_file_exists', Mock(return_value=True))
     def test_get_major_version(self):
         with patch.object(builtins, 'open', mock_open(read_data='9.4')):
@@ -498,13 +554,14 @@ class TestPostgresql(BaseTestPostgresql):
             self.assertEqual(self.p.get_major_version(), 0)
 
     def test_postmaster_start_time(self):
-        with patch.object(MockCursor, "fetchone", Mock(return_value=('foo', True, '', '', '', '', False))):
-            self.assertEqual(self.p.postmaster_start_time(), 'foo')
+        now = datetime.datetime.now()
+        with patch.object(MockCursor, "fetchone", Mock(return_value=(now, True, '', '', '', '', False))):
+            self.assertEqual(self.p.postmaster_start_time(), now.isoformat(sep=' '))
             t = Thread(target=self.p.postmaster_start_time)
             t.start()
             t.join()
 
-        with patch.object(MockCursor, "execute", side_effect=psycopg2.Error):
+        with patch.object(MockCursor, "execute", side_effect=psycopg.Error):
             self.assertIsNone(self.p.postmaster_start_time())
 
     def test_check_for_startup(self):
@@ -585,37 +642,44 @@ class TestPostgresql(BaseTestPostgresql):
 
     def test_pick_sync_standby(self):
         cluster = Cluster(True, None, self.leader, 0, [self.me, self.other, self.leadermem], None,
-                          SyncState(0, self.me.name, self.leadermem.name), None)
+                          SyncState(0, self.me.name, self.leadermem.name), None, None)
+        mock_cursor = Mock()
+        mock_cursor.fetchone.return_value = ('remote_apply',)
 
-        with patch.object(Postgresql, "query", return_value=[
-                    (self.leadermem.name, 'streaming', 'sync'),
-                    (self.me.name, 'streaming', 'async'),
-                    (self.other.name, 'streaming', 'async'),
+        with patch.object(Postgresql, "query", side_effect=[
+                    mock_cursor,
+                    [(self.leadermem.name, 'sync', 1),
+                     (self.me.name, 'async', 2),
+                     (self.other.name, 'async', 2)]
                 ]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (self.leadermem.name, True))
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([self.leadermem.name], [self.leadermem.name]))
 
-        with patch.object(Postgresql, "query", return_value=[
-                    (self.me.name, 'streaming', 'async'),
-                    (self.leadermem.name, 'streaming', 'potential'),
-                    (self.other.name, 'streaming', 'async'),
+        with patch.object(Postgresql, "query", side_effect=[
+                    mock_cursor,
+                    [(self.leadermem.name, 'potential', 1),
+                     (self.me.name, 'async', 2),
+                     (self.other.name, 'async', 2)]
                 ]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (self.leadermem.name, False))
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([self.leadermem.name], []))
 
-        with patch.object(Postgresql, "query", return_value=[
-                    (self.me.name, 'streaming', 'async'),
-                    (self.other.name, 'streaming', 'async'),
+        with patch.object(Postgresql, "query", side_effect=[
+                    mock_cursor,
+                    [(self.me.name, 'async', 1),
+                     (self.other.name, 'async', 2)]
                 ]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (self.me.name, False))
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([self.me.name], []))
 
-        with patch.object(Postgresql, "query", return_value=[
-                    ('missing', 'streaming', 'sync'),
-                    (self.me.name, 'streaming', 'async'),
-                    (self.other.name, 'streaming', 'async'),
+        with patch.object(Postgresql, "query", side_effect=[
+                    mock_cursor,
+                    [('missing', 'sync', 1),
+                     (self.me.name, 'async', 2),
+                     (self.other.name, 'async', 3)]
                 ]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (self.me.name, False))
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([self.me.name], []))
 
-        with patch.object(Postgresql, "query", return_value=[]):
-            self.assertEqual(self.p.pick_synchronous_standby(cluster), (None, False))
+        with patch.object(Postgresql, "query", side_effect=[mock_cursor, []]):
+            self.p._major_version = 90400
+            self.assertEqual(self.p.pick_synchronous_standby(cluster), ([], []))
 
     def test_set_sync_standby(self):
         def value_in_conf():
@@ -625,21 +689,21 @@ class TestPostgresql(BaseTestPostgresql):
                         return line.strip()
 
         mock_reload = self.p.reload = Mock()
-        self.p.config.set_synchronous_standby('n1')
+        self.p.config.set_synchronous_standby(['n1'])
         self.assertEqual(value_in_conf(), "synchronous_standby_names = 'n1'")
         mock_reload.assert_called()
 
         mock_reload.reset_mock()
-        self.p.config.set_synchronous_standby('n1')
+        self.p.config.set_synchronous_standby(['n1'])
         mock_reload.assert_not_called()
         self.assertEqual(value_in_conf(), "synchronous_standby_names = 'n1'")
 
-        self.p.config.set_synchronous_standby('n2')
+        self.p.config.set_synchronous_standby(['n1', 'n2'])
         mock_reload.assert_called()
-        self.assertEqual(value_in_conf(), "synchronous_standby_names = 'n2'")
+        self.assertEqual(value_in_conf(), "synchronous_standby_names = '2 (n1,n2)'")
 
         mock_reload.reset_mock()
-        self.p.config.set_synchronous_standby(None)
+        self.p.config.set_synchronous_standby([])
         mock_reload.assert_called()
         self.assertEqual(value_in_conf(), None)
 
@@ -660,7 +724,7 @@ class TestPostgresql(BaseTestPostgresql):
             self.p.stop(on_safepoint=mock_callback)
 
             mock_postmaster.is_running.side_effect = [True, False, False]
-            with patch.object(MockCursor, "execute", Mock(side_effect=psycopg2.Error)):
+            with patch.object(MockCursor, "execute", Mock(side_effect=psycopg.Error)):
                 self.p.stop(on_safepoint=mock_callback)
 
     def test_terminate_starting_postmaster(self):
@@ -669,49 +733,15 @@ class TestPostgresql(BaseTestPostgresql):
         mock_postmaster.signal_stop.assert_called()
         mock_postmaster.wait.assert_called()
 
-    def test_read_postmaster_opts(self):
-        m = mock_open(read_data='/usr/lib/postgres/9.6/bin/postgres "-D" "data/postgresql0" \
-"--listen_addresses=127.0.0.1" "--port=5432" "--hot_standby=on" "--wal_level=hot_standby" \
-"--wal_log_hints=on" "--max_wal_senders=5" "--max_replication_slots=5"\n')
-        with patch.object(builtins, 'open', m):
-            data = self.p.read_postmaster_opts()
-            self.assertEqual(data['wal_level'], 'hot_standby')
-            self.assertEqual(int(data['max_replication_slots']), 5)
-            self.assertEqual(data.get('D'), None)
-
-            m.side_effect = IOError
-            data = self.p.read_postmaster_opts()
-            self.assertEqual(data, dict())
-
-    @patch('psutil.Popen')
-    def test_single_user_mode(self, subprocess_popen_mock):
-        subprocess_popen_mock.return_value.wait.return_value = 0
-        self.assertEqual(self.p.single_user_mode('CHECKPOINT', {'archive_mode': 'on'}), 0)
-
-    @patch('os.listdir', Mock(side_effect=[OSError, ['a', 'b']]))
-    @patch('os.unlink', Mock(side_effect=OSError))
-    @patch('os.remove', Mock())
-    @patch('os.path.islink', Mock(side_effect=[True, False]))
-    @patch('os.path.isfile', Mock(return_value=True))
-    def test_cleanup_archive_status(self):
-        self.p.cleanup_archive_status()
-        self.p.cleanup_archive_status()
-
-    @patch('os.unlink', Mock())
-    @patch('os.listdir', Mock(return_value=[]))
-    @patch('os.path.isfile', Mock(return_value=True))
-    @patch.object(Postgresql, 'read_postmaster_opts', Mock(return_value={}))
-    @patch.object(Postgresql, 'single_user_mode', Mock(return_value=0))
-    def test_fix_cluster_state(self):
-        self.assertTrue(self.p.fix_cluster_state())
-
     def test_replica_cached_timeline(self):
-        self.assertEqual(self.p.replica_cached_timeline(1), 2)
+        self.assertEqual(self.p.replica_cached_timeline(2), 3)
 
     def test_get_master_timeline(self):
         self.assertEqual(self.p.get_master_timeline(), 1)
 
     @patch.object(Postgresql, 'get_postgres_role_from_data_directory', Mock(return_value='replica'))
+    @patch.object(Bootstrap, 'running_custom_bootstrap', PropertyMock(return_value=True))
+    @patch.object(Bootstrap, 'keep_existing_recovery_conf', PropertyMock(return_value=True))
     def test__build_effective_configuration(self):
         with patch.object(Postgresql, 'controldata',
                           Mock(return_value={'max_connections setting': '200',
@@ -726,3 +756,23 @@ class TestPostgresql(BaseTestPostgresql):
     @patch('os.path.isfile', Mock(return_value=False))
     def test_pgpass_is_dir(self):
         self.assertRaises(PatroniException, self.setUp)
+
+    @patch.object(Postgresql, '_query', Mock(side_effect=RetryFailedError('')))
+    def test_received_timeline(self):
+        self.p.set_role('standby_leader')
+        self.p.reset_cluster_info_state(None)
+        self.assertRaises(PostgresConnectionException, self.p.received_timeline)
+
+    def test__write_recovery_params(self):
+        self.p.config._write_recovery_params(Mock(), {'pause_at_recovery_target': 'false'})
+        with patch.object(Postgresql, 'major_version', PropertyMock(return_value=90400)):
+            self.p.config._write_recovery_params(Mock(), {'recovery_target_action': 'PROMOTE'})
+
+    @patch.object(Postgresql, 'is_running', Mock(return_value=True))
+    def test_set_enforce_hot_standby_feedback(self):
+        self.p.set_enforce_hot_standby_feedback(True)
+
+    @patch.object(Postgresql, 'major_version', PropertyMock(return_value=140000))
+    @patch.object(Postgresql, '_cluster_info_state_get', Mock(return_value=True))
+    def test_handle_parameter_change(self):
+        self.p.handle_parameter_change()

tests/test_raft.py

@@ -0,0 +1,162 @@
+import os
+import unittest
+import tempfile
+import time
+
+from mock import Mock, PropertyMock, patch
+from patroni.dcs.raft import DynMemberSyncObj, KVStoreTTL, Raft, SyncObjUtility, TCPTransport, _TCPTransport
+from pysyncobj import SyncObjConf, FAIL_REASON
+
+
+def remove_files(prefix):
+    for f in ('journal', 'journal.meta', 'dump'):
+        f = prefix + f
+        if os.path.isfile(f):
+            for i in range(0, 15):
+                try:
+                    if os.path.isfile(f):
+                        os.unlink(f)
+                        break
+                    else:
+                        break
+                except Exception:
+                    time.sleep(1.0)
+
+
+class TestTCPTransport(unittest.TestCase):
+
+    @patch.object(TCPTransport, '__init__', Mock())
+    @patch.object(TCPTransport, 'setOnUtilityMessageCallback', Mock())
+    @patch.object(TCPTransport, '_connectIfNecessarySingle', Mock(side_effect=Exception))
+    def test__connectIfNecessarySingle(self):
+        t = _TCPTransport(Mock(), None, [])
+        self.assertFalse(t._connectIfNecessarySingle(None))
+
+
+@patch('pysyncobj.tcp_server.TcpServer.bind', Mock())
+class TestDynMemberSyncObj(unittest.TestCase):
+
+    @patch('pysyncobj.tcp_server.TcpServer.bind', Mock())
+    def setUp(self):
+        self.conf = SyncObjConf(appendEntriesUseBatch=False, dynamicMembershipChange=True, autoTick=False)
+        self.so = DynMemberSyncObj('127.0.0.1:1234', ['127.0.0.1:1235'], self.conf)
+
+    @patch.object(SyncObjUtility, 'executeCommand')
+    def test_add_member(self, mock_execute_command):
+        mock_execute_command.return_value = [{'addr': '127.0.0.1:1235'}, {'addr': '127.0.0.1:1236'}]
+        mock_execute_command.ver = 0
+        DynMemberSyncObj('127.0.0.1:1234', ['127.0.0.1:1235'], self.conf)
+        self.conf.dynamicMembershipChange = False
+        DynMemberSyncObj('127.0.0.1:1234', ['127.0.0.1:1235'], self.conf)
+
+    def test_getMembers(self):
+        mock_conn = Mock()
+        self.so._SyncObj__transport._onIncomingMessageReceived(mock_conn, ['members'])
+
+    def test__SyncObj__doChangeCluster(self):
+        self.so._SyncObj__doChangeCluster(['add', '127.0.0.1:1236'])
+
+
+@patch.object(SyncObjConf, 'fullDumpFile', PropertyMock(return_value=None), create=True)
+@patch.object(SyncObjConf, 'journalFile', PropertyMock(return_value=None), create=True)
+class TestKVStoreTTL(unittest.TestCase):
+
+    @patch.object(SyncObjConf, 'fullDumpFile', PropertyMock(return_value=None), create=True)
+    @patch.object(SyncObjConf, 'journalFile', PropertyMock(return_value=None), create=True)
+    def setUp(self):
+        callback = Mock()
+        callback.replicated = False
+        self.so = KVStoreTTL(None, callback, callback, self_addr='127.0.0.1:1234')
+        self.so.startAutoTick()
+        self.so.set_retry_timeout(10)
+
+    def tearDown(self):
+        if self.so:
+            self.so.destroy()
+
+    def test_set(self):
+        self.assertTrue(self.so.set('foo', 'bar', prevExist=False, ttl=30))
+        self.assertFalse(self.so.set('foo', 'bar', prevExist=False, ttl=30))
+        self.assertFalse(self.so.retry(self.so._set, 'foo', {'value': 'buz', 'created': 1, 'updated': 1}, prevValue=''))
+        self.assertTrue(self.so.retry(self.so._set, 'foo', {'value': 'buz', 'created': 1, 'updated': 1}))
+
+    def test_delete(self):
+        self.so.autoTickPeriod = 0.2
+        self.so.set('foo', 'bar')
+        self.so.set('fooo', 'bar')
+        self.assertFalse(self.so.delete('foo', prevValue='buz'))
+        self.assertTrue(self.so.delete('foo', recursive=True))
+        self.assertFalse(self.so.retry(self.so._delete, 'foo', prevValue=''))
+
+    def test_expire(self):
+        self.so.set('foo', 'bar', ttl=0.001)
+        time.sleep(1)
+        self.assertIsNone(self.so.get('foo'))
+        self.assertEqual(self.so.get('foo', recursive=True), {})
+
+    @patch('time.sleep', Mock())
+    def test_retry(self):
+        return_values = [FAIL_REASON.QUEUE_FULL] * 2 + [FAIL_REASON.SUCCESS, FAIL_REASON.REQUEST_DENIED]
+
+        def test(callback):
+            callback(True, return_values.pop(0))
+
+        with patch('time.time', Mock(side_effect=[1, 100])):
+            self.assertFalse(self.so.retry(test))
+
+        self.assertTrue(self.so.retry(test))
+        self.assertFalse(self.so.retry(test))
+
+    def test_on_ready_override(self):
+        self.assertTrue(self.so.set('foo', 'bar'))
+        self.so.destroy()
+        self.so = None
+        so = KVStoreTTL(Mock(), None, None, self_addr='127.0.0.1:1234',
+                        partner_addrs=['127.0.0.1:1235'], patronictl=True)
+        so.doTick(0)
+        so.destroy()
+
+
+class TestRaft(unittest.TestCase):
+
+    _TMP = tempfile.gettempdir()
+
+    def test_raft(self):
+        raft = Raft({'ttl': 30, 'scope': 'test', 'name': 'pg', 'self_addr': '127.0.0.1:1234',
+                     'retry_timeout': 10, 'data_dir': self._TMP})
+        raft.reload_config({'retry_timeout': 20, 'ttl': 60, 'loop_wait': 10})
+        self.assertTrue(raft._sync_obj.set(raft.members_path + 'legacy', '{"version":"2.0.0"}'))
+        self.assertTrue(raft.touch_member(''))
+        self.assertTrue(raft.initialize())
+        self.assertTrue(raft.cancel_initialization())
+        self.assertTrue(raft.set_config_value('{}'))
+        self.assertTrue(raft.write_sync_state('foo', 'bar'))
+        self.assertTrue(raft.manual_failover('foo', 'bar'))
+        raft.get_cluster()
+        self.assertTrue(raft._sync_obj.set(raft.status_path, '{"optime":1234567,"slots":{"ls":12345}}'))
+        raft.get_cluster()
+        self.assertTrue(raft.update_leader('1'))
+        self.assertTrue(raft._sync_obj.set(raft.status_path, '{'))
+        raft.get_cluster()
+        self.assertTrue(raft.delete_sync_state())
+        self.assertTrue(raft.delete_leader())
+        self.assertTrue(raft.set_history_value(''))
+        self.assertTrue(raft.delete_cluster())
+        raft.get_cluster()
+        self.assertTrue(raft.take_leader())
+        raft.watch(None, 0.001)
+        raft._sync_obj.destroy()
+
+    def tearDown(self):
+        remove_files(os.path.join(self._TMP, '127.0.0.1:1234.'))
+
+    def setUp(self):
+        self.tearDown()
+
+    @patch('patroni.dcs.raft.KVStoreTTL')
+    @patch('threading.Event')
+    def test_init(self, mock_event, mock_kvstore):
+        mock_kvstore.return_value.applied_local_log = False
+        mock_event.return_value.isSet.side_effect = [False, True]
+        self.assertIsNotNone(Raft({'ttl': 30, 'scope': 'test', 'name': 'pg', 'patronictl': True,
+                                   'self_addr': '1', 'data_dir': self._TMP}))

tests/test_raft_controller.py

@@ -0,0 +1,44 @@
+import logging
+import os
+import unittest
+
+from mock import Mock, patch
+from pysyncobj import SyncObj
+from patroni.config import Config
+from patroni.raft_controller import RaftController, main as _main
+
+from . import SleepException
+from .test_raft import remove_files
+
+
+class TestPatroniRaftController(unittest.TestCase):
+
+    SELF_ADDR = '127.0.0.1:5360'
+
+    def remove_files(self):
+        remove_files(self.SELF_ADDR + '.')
+
+    @patch('pysyncobj.tcp_server.TcpServer.bind', Mock())
+    def setUp(self):
+        self._handlers = logging.getLogger().handlers[:]
+        self.remove_files()
+        os.environ['PATRONI_RAFT_SELF_ADDR'] = self.SELF_ADDR
+        config = Config('postgres0.yml', validator=None)
+        self.rc = RaftController(config)
+
+    def tearDown(self):
+        logging.getLogger().handlers[:] = self._handlers
+        self.remove_files()
+
+    def test_reload_config(self):
+        self.rc.reload_config()
+
+    @patch('logging.Logger.error', Mock(side_effect=SleepException))
+    @patch.object(SyncObj, 'doTick', Mock(side_effect=Exception))
+    def test_run(self):
+        self.assertRaises(SleepException, self.rc.run)
+        self.rc.shutdown()
+
+    @patch('sys.argv', ['patroni'])
+    def test_patroni_raft_controller_main(self):
+        self.assertRaises(SystemExit, _main)

tests/test_rewind.py

@@ -1,10 +1,11 @@
-from mock import Mock, PropertyMock, patch
+from mock import Mock, PropertyMock, patch, mock_open
 
 from patroni.postgresql import Postgresql
 from patroni.postgresql.cancellable import CancellableSubprocess
 from patroni.postgresql.rewind import Rewind
+from six.moves import builtins
 
-from . import BaseTestPostgresql, MockCursor, psycopg2_connect
+from . import BaseTestPostgresql, MockCursor, psycopg_connect
 
 
 class MockThread(object):
@@ -17,8 +18,36 @@ class MockThread(object):
         self._target(*self._args)
 
 
+def mock_cancellable_call(*args, **kwargs):
+    communicate = kwargs.pop('communicate', None)
+    if isinstance(communicate, dict):
+        communicate.update(stdout=b'', stderr=b'pg_rewind: error: could not open file ' +
+                                              b'"data/postgresql0/pg_xlog/000000010000000000000003": No such file')
+    return 1
+
+
+def mock_cancellable_call0(*args, **kwargs):
+    communicate = kwargs.pop('communicate', None)
+    if isinstance(communicate, dict):
+        communicate.update(stdout=b'', stderr=b'')
+    return 0
+
+
+def mock_cancellable_call1(*args, **kwargs):
+    communicate = kwargs.pop('communicate', None)
+    if isinstance(communicate, dict):
+        communicate.update(stdout=b'', stderr=b'')
+    return 1
+
+
+def mock_single_user_mode(self, communicate, options):
+    communicate['stdout'] = b'foo'
+    communicate['stderr'] = b'bar'
+    return 1
+
+
 @patch('subprocess.call', Mock(return_value=0))
-@patch('psycopg2.connect', psycopg2_connect)
+@patch('patroni.psycopg.connect', psycopg_connect)
 class TestRewind(BaseTestPostgresql):
 
     def setUp(self):
@@ -35,13 +64,23 @@ class TestRewind(BaseTestPostgresql):
         self.p.config._config['use_pg_rewind'] = False
         self.assertFalse(self.r.can_rewind)
 
-    @patch.object(CancellableSubprocess, 'call')
-    def test_pg_rewind(self, mock_cancellable_subprocess_call):
+    def test_pg_rewind(self):
         r = {'user': '', 'host': '', 'port': '', 'database': '', 'password': ''}
-        mock_cancellable_subprocess_call.return_value = 0
-        self.assertTrue(self.r.pg_rewind(r))
-        mock_cancellable_subprocess_call.side_effect = OSError
-        self.assertFalse(self.r.pg_rewind(r))
+        with patch.object(Postgresql, 'major_version', PropertyMock(return_value=130000)),\
+                patch.object(CancellableSubprocess, 'call', Mock(return_value=None)):
+            with patch('subprocess.check_output', Mock(return_value=b'boo')):
+                self.assertFalse(self.r.pg_rewind(r))
+            with patch('subprocess.check_output', Mock(side_effect=Exception)):
+                self.assertFalse(self.r.pg_rewind(r))
+
+        with patch.object(Postgresql, 'major_version', PropertyMock(return_value=120000)),\
+                patch('subprocess.check_output', Mock(return_value=b'foo %f %p %r %% % %')):
+            with patch.object(CancellableSubprocess, 'call', mock_cancellable_call):
+                self.assertFalse(self.r.pg_rewind(r))
+            with patch.object(CancellableSubprocess, 'call', mock_cancellable_call0):
+                self.assertTrue(self.r.pg_rewind(r))
+            with patch.object(CancellableSubprocess, 'call', mock_cancellable_call1):
+                self.assertFalse(self.r.pg_rewind(r))
 
     @patch.object(Rewind, 'can_rewind', PropertyMock(return_value=True))
     def test__get_local_timeline_lsn(self):
@@ -49,14 +88,15 @@ class TestRewind(BaseTestPostgresql):
         with patch.object(Postgresql, 'controldata',
                           Mock(return_value={'Database cluster state': 'shut down in recovery',
                                              'Minimum recovery ending location': '0/0',
-                                             "Min recovery ending loc's timeline": '0'})):
+                                             "Min recovery ending loc's timeline": '0',
+                                             'Latest checkpoint location': '0/'})):
             self.r.rewind_or_reinitialize_needed_and_possible(self.leader)
 
         with patch.object(Postgresql, 'is_running', Mock(return_value=True)):
-            with patch.object(MockCursor, 'fetchone', Mock(side_effect=[(False, ), Exception])):
+            with patch.object(MockCursor, 'fetchone', Mock(side_effect=[(0, 0, 1, 1, 0, 0, 0, 0, 0, None), Exception])):
                 self.r.rewind_or_reinitialize_needed_and_possible(self.leader)
 
-    @patch.object(CancellableSubprocess, 'call', Mock(return_value=0))
+    @patch.object(CancellableSubprocess, 'call', mock_cancellable_call)
     @patch.object(Postgresql, 'checkpoint', side_effect=['', '1'],)
     @patch.object(Postgresql, 'stop', Mock(return_value=False))
     @patch.object(Postgresql, 'start', Mock())
@@ -82,51 +122,119 @@ class TestRewind(BaseTestPostgresql):
         with patch.object(Postgresql, 'is_running', Mock(return_value=True)):
             self.r.execute(self.leader)
 
+    @patch('patroni.postgresql.rewind.logger.info')
+    def test__log_master_history(self, mock_logger):
+        history = [[n, n, ''] for n in range(1, 10)]
+        self.r._log_master_history(history, 1)
+        expected = '\n'.join(['{0}\t0/{0}\t'.format(n) for n in range(1, 4)] + ['...', '9\t0/9\t'])
+        self.assertEqual(mock_logger.call_args[0][1], expected)
+
     @patch.object(Postgresql, 'start', Mock())
     @patch.object(Rewind, 'can_rewind', PropertyMock(return_value=True))
-    @patch.object(Rewind, '_get_local_timeline_lsn', Mock(return_value=(2, '40159C1')))
+    @patch.object(Rewind, '_get_local_timeline_lsn')
     @patch.object(Rewind, 'check_leader_is_not_in_recovery')
-    def test__check_timeline_and_lsn(self, mock_check_leader_is_not_in_recovery):
+    def test__check_timeline_and_lsn(self, mock_check_leader_is_not_in_recovery, mock_get_local_timeline_lsn):
+        mock_get_local_timeline_lsn.return_value = (True, 2, 67197377)
         mock_check_leader_is_not_in_recovery.return_value = False
         self.r.trigger_check_diverged_lsn()
         self.assertFalse(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
         self.leader = self.leader.member
         self.assertFalse(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
         mock_check_leader_is_not_in_recovery.return_value = True
-        self.assertFalse(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
+        self.assertTrue(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
+        self.r.reset_state()
         self.r.trigger_check_diverged_lsn()
-        with patch('psycopg2.connect', Mock(side_effect=Exception)):
+        with patch('patroni.psycopg.connect', Mock(side_effect=Exception)):
             self.assertFalse(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
         self.r.trigger_check_diverged_lsn()
-        with patch.object(MockCursor, 'fetchone', Mock(side_effect=[('', 2, '0/0'), ('', b'3\t0/40159C0\tn\n')])):
-            self.assertFalse(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
+        with patch.object(MockCursor, 'fetchone', Mock(side_effect=[('', 3, '0/0'), ('', b'1\t0/40159C0\tn\n')])):
+            self.assertTrue(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
+        self.r.reset_state()
         self.r.trigger_check_diverged_lsn()
         with patch.object(MockCursor, 'fetchone', Mock(return_value=('', 1, '0/0'))):
-            with patch.object(Rewind, '_get_local_timeline_lsn', Mock(return_value=(1, '0/0'))):
+            with patch.object(Rewind, '_get_local_timeline_lsn', Mock(return_value=(True, 1, '0/0'))):
                 self.assertFalse(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
             self.r.trigger_check_diverged_lsn()
             self.assertTrue(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
 
+        self.r.reset_state()
+        self.r.trigger_check_diverged_lsn()
+        mock_get_local_timeline_lsn.return_value = (False, 2, 67296664)
+        self.assertTrue(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
+
+        with patch('subprocess.Popen') as mock_popen:
+            mock_popen.return_value.communicate.return_value = (
+                b'0, lsn: 0/040159C1, prev 0/\n',
+                b'pg_waldump: fatal: error in WAL record at 0/40159C1: invalid record length at /: wanted 24, got 0\n'
+            )
+            self.r.reset_state()
+            self.r.trigger_check_diverged_lsn()
+            mock_get_local_timeline_lsn.return_value = (False, 2, 67197377)
+            self.assertTrue(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
+            self.r.reset_state()
+            self.r.trigger_check_diverged_lsn()
+            mock_popen.side_effect = Exception
+            self.assertTrue(self.r.rewind_or_reinitialize_needed_and_possible(self.leader))
+
     @patch.object(MockCursor, 'fetchone', Mock(side_effect=[(True,), Exception]))
     def test_check_leader_is_not_in_recovery(self):
-        self.r.check_leader_is_not_in_recovery()
-        self.r.check_leader_is_not_in_recovery()
+        self.r.check_leader_is_not_in_recovery({})
+        self.r.check_leader_is_not_in_recovery({})
+
+    def test_read_postmaster_opts(self):
+        m = mock_open(read_data='/usr/lib/postgres/9.6/bin/postgres "-D" "data/postgresql0" \
+"--listen_addresses=127.0.0.1" "--port=5432" "--hot_standby=on" "--wal_level=hot_standby" \
+"--wal_log_hints=on" "--max_wal_senders=5" "--max_replication_slots=5"\n')
+        with patch.object(builtins, 'open', m):
+            data = self.r.read_postmaster_opts()
+            self.assertEqual(data['wal_level'], 'hot_standby')
+            self.assertEqual(int(data['max_replication_slots']), 5)
+            self.assertEqual(data.get('D'), None)
+
+            m.side_effect = IOError
+            data = self.r.read_postmaster_opts()
+            self.assertEqual(data, dict())
+
+    @patch('psutil.Popen')
+    def test_single_user_mode(self, subprocess_popen_mock):
+        subprocess_popen_mock.return_value.wait.return_value = 0
+        subprocess_popen_mock.return_value.communicate.return_value = ('', '')
+        self.assertEqual(self.r.single_user_mode({'input': 'CHECKPOINT'}, {'archive_mode': 'on'}), 0)
+
+    @patch('os.listdir', Mock(side_effect=[OSError, ['a', 'b']]))
+    @patch('os.unlink', Mock(side_effect=OSError))
+    @patch('os.remove', Mock())
+    @patch('os.path.islink', Mock(side_effect=[True, False]))
+    @patch('os.path.isfile', Mock(return_value=True))
+    def test_cleanup_archive_status(self):
+        self.r.cleanup_archive_status()
+        self.r.cleanup_archive_status()
+
+    @patch('os.unlink', Mock())
+    @patch('os.listdir', Mock(return_value=[]))
+    @patch('os.path.isfile', Mock(return_value=True))
+    @patch.object(Rewind, 'read_postmaster_opts', Mock(return_value={}))
+    @patch.object(Rewind, 'single_user_mode', mock_single_user_mode)
+    def test_ensure_clean_shutdown(self):
+        self.assertIsNone(self.r.ensure_clean_shutdown())
 
     @patch('patroni.postgresql.rewind.Thread', MockThread)
     @patch.object(Postgresql, 'controldata')
     @patch.object(Postgresql, 'checkpoint')
-    def test_ensure_checkpoint_after_promote(self, mock_checkpoint, mock_controldata):
-        mock_checkpoint.return_value = None
-        self.r.ensure_checkpoint_after_promote()
-        self.r.ensure_checkpoint_after_promote()
-
-        self.r.reset_state()
+    @patch.object(Postgresql, 'get_master_timeline')
+    def test_ensure_checkpoint_after_promote(self, mock_get_master_timeline, mock_checkpoint, mock_controldata):
         mock_controldata.return_value = {"Latest checkpoint's TimeLineID": 1}
-        mock_checkpoint.side_effect = Exception
-        self.r.ensure_checkpoint_after_promote()
-        self.r.ensure_checkpoint_after_promote()
+        mock_get_master_timeline.return_value = 1
+        self.r.ensure_checkpoint_after_promote(Mock())
 
         self.r.reset_state()
+        mock_get_master_timeline.return_value = 2
+        mock_checkpoint.return_value = 0
+        self.r.ensure_checkpoint_after_promote(Mock())
+        self.r.ensure_checkpoint_after_promote(Mock())
+
+        self.r.reset_state()
+
         mock_controldata.side_effect = TypeError
-        self.r.ensure_checkpoint_after_promote()
-        self.r.ensure_checkpoint_after_promote()
+        mock_checkpoint.side_effect = Exception
+        self.r.ensure_checkpoint_after_promote(Mock())

tests/test_slots.py

@@ -0,0 +1,124 @@
+import mock
+import os
+import unittest
+
+
+from mock import Mock, PropertyMock, patch
+
+from patroni import psycopg
+from patroni.dcs import Cluster, ClusterConfig, Member
+from patroni.postgresql import Postgresql
+from patroni.postgresql.slots import SlotsHandler, fsync_dir
+
+from . import BaseTestPostgresql, psycopg_connect, MockCursor
+
+
+@patch('subprocess.call', Mock(return_value=0))
+@patch('patroni.psycopg.connect', psycopg_connect)
+@patch.object(Postgresql, 'is_running', Mock(return_value=True))
+class TestSlotsHandler(BaseTestPostgresql):
+
+    @patch('subprocess.call', Mock(return_value=0))
+    @patch('os.rename', Mock())
+    @patch('patroni.postgresql.CallbackExecutor', Mock())
+    @patch.object(Postgresql, 'get_major_version', Mock(return_value=130000))
+    @patch.object(Postgresql, 'is_running', Mock(return_value=True))
+    def setUp(self):
+        super(TestSlotsHandler, self).setUp()
+        self.s = self.p.slots_handler
+        self.p.start()
+
+    def test_sync_replication_slots(self):
+        config = ClusterConfig(1, {'slots': {'test_3': {'database': 'a', 'plugin': 'b'},
+                                             'A': 0, 'ls': 0, 'b': {'type': 'logical', 'plugin': '1'}},
+                                   'ignore_slots': [{'name': 'blabla'}]}, 1)
+        cluster = Cluster(True, config, self.leader, 0,
+                          [self.me, self.other, self.leadermem], None, None, None, {'test_3': 10})
+        with mock.patch('patroni.postgresql.Postgresql._query', Mock(side_effect=psycopg.OperationalError)):
+            self.s.sync_replication_slots(cluster, False)
+        self.p.set_role('standby_leader')
+        self.s.sync_replication_slots(cluster, False)
+        self.p.set_role('replica')
+        with patch.object(Postgresql, 'is_leader', Mock(return_value=False)):
+            self.s.sync_replication_slots(cluster, False)
+        self.p.set_role('master')
+        with mock.patch('patroni.postgresql.Postgresql.role', new_callable=PropertyMock(return_value='replica')):
+            self.s.sync_replication_slots(cluster, False)
+        with patch.object(SlotsHandler, 'drop_replication_slot', Mock(return_value=True)),\
+                patch('patroni.dcs.logger.error', new_callable=Mock()) as errorlog_mock:
+            alias1 = Member(0, 'test-3', 28, {'conn_url': 'postgres://replicator:[email protected]:5436/postgres'})
+            alias2 = Member(0, 'test.3', 28, {'conn_url': 'postgres://replicator:[email protected]:5436/postgres'})
+            cluster.members.extend([alias1, alias2])
+            self.s.sync_replication_slots(cluster, False)
+            self.assertEqual(errorlog_mock.call_count, 5)
+            ca = errorlog_mock.call_args_list[0][0][1]
+            self.assertTrue("test-3" in ca, "non matching {0}".format(ca))
+            self.assertTrue("test.3" in ca, "non matching {0}".format(ca))
+            with patch.object(Postgresql, 'major_version', PropertyMock(return_value=90618)):
+                self.s.sync_replication_slots(cluster, False)
+
+    def test_process_permanent_slots(self):
+        config = ClusterConfig(1, {'slots': {'ls': {'database': 'a', 'plugin': 'b'}},
+                                   'ignore_slots': [{'name': 'blabla'}]}, 1)
+        cluster = Cluster(True, config, self.leader, 0, [self.me, self.other, self.leadermem], None, None, None, None)
+
+        self.s.sync_replication_slots(cluster, False)
+        with patch.object(Postgresql, '_query') as mock_query:
+            self.p.reset_cluster_info_state(None)
+            mock_query.return_value.fetchone.return_value = (
+                1, 0, 0, 0, 0, 0, 0, 0, 0,
+                [{"slot_name": "ls", "type": "logical", "datoid": 5, "plugin": "b",
+                  "confirmed_flush_lsn": 12345, "catalog_xmin": 105}])
+            self.assertEqual(self.p.slots(), {'ls': 12345})
+
+            self.p.reset_cluster_info_state(None)
+            mock_query.return_value.fetchone.return_value = (
+                1, 0, 0, 0, 0, 0, 0, 0, 0,
+                [{"slot_name": "ls", "type": "logical", "datoid": 6, "plugin": "b",
+                  "confirmed_flush_lsn": 12345, "catalog_xmin": 105}])
+            self.assertEqual(self.p.slots(), {})
+
+    @patch.object(Postgresql, 'is_leader', Mock(return_value=False))
+    def test__ensure_logical_slots_replica(self):
+        self.p.set_role('replica')
+        config = ClusterConfig(1, {'slots': {'ls': {'database': 'a', 'plugin': 'b'}}}, 1)
+        cluster = Cluster(True, config, self.leader, 0,
+                          [self.me, self.other, self.leadermem], None, None, None, {'ls': 12346})
+        self.assertEqual(self.s.sync_replication_slots(cluster, False), [])
+        self.s._schedule_load_slots = False
+        with patch.object(MockCursor, 'execute', Mock(side_effect=psycopg.UndefinedFile)):
+            self.assertEqual(self.s.sync_replication_slots(cluster, False), ['ls'])
+        cluster.slots['ls'] = 'a'
+        self.assertEqual(self.s.sync_replication_slots(cluster, False), [])
+        with patch.object(MockCursor, 'rowcount', PropertyMock(return_value=1), create=True):
+            self.assertEqual(self.s.sync_replication_slots(cluster, False), ['ls'])
+
+    @patch.object(MockCursor, 'execute', Mock(side_effect=psycopg.OperationalError))
+    def test_copy_logical_slots(self):
+        self.s.copy_logical_slots(self.leader, ['foo'])
+
+    @patch.object(Postgresql, 'stop', Mock(return_value=True))
+    @patch.object(Postgresql, 'start', Mock(return_value=True))
+    @patch.object(Postgresql, 'is_leader', Mock(return_value=False))
+    def test_check_logical_slots_readiness(self):
+        self.s.copy_logical_slots(self.leader, ['ls'])
+        config = ClusterConfig(1, {'slots': {'ls': {'database': 'a', 'plugin': 'b'}}}, 1)
+        cluster = Cluster(True, config, self.leader, 0,
+                          [self.me, self.other, self.leadermem], None, None, None, {'ls': 12345})
+        self.assertEqual(self.s.sync_replication_slots(cluster, False), [])
+        with patch.object(MockCursor, 'rowcount', PropertyMock(return_value=1), create=True):
+            self.s.check_logical_slots_readiness(cluster, False, None)
+
+    @patch.object(Postgresql, 'stop', Mock(return_value=True))
+    @patch.object(Postgresql, 'start', Mock(return_value=True))
+    @patch.object(Postgresql, 'is_leader', Mock(return_value=False))
+    def test_on_promote(self):
+        self.s.copy_logical_slots(self.leader, ['ls'])
+        self.s.on_promote()
+
+    @unittest.skipIf(os.name == 'nt', "Windows not supported")
+    @patch('os.open', Mock())
+    @patch('os.close', Mock())
+    @patch('os.fsync', Mock(side_effect=OSError))
+    def test_fsync_dir(self):
+        self.assertRaises(OSError, fsync_dir, 'foo')

tests/test_utils.py

@@ -2,7 +2,7 @@ import unittest
 
 from mock import Mock, patch
 from patroni.exceptions import PatroniException
-from patroni.utils import Retry, RetryFailedError, polling_loop, validate_directory
+from patroni.utils import Retry, RetryFailedError, enable_keepalive, find_executable, polling_loop, validate_directory
 
 
 class TestUtils(unittest.TestCase):
@@ -33,6 +33,23 @@ class TestUtils(unittest.TestCase):
     def test_validate_directory_is_not_a_directory(self):
         self.assertRaises(PatroniException, validate_directory, "/tmp")
 
+    def test_enable_keepalive(self):
+        with patch('socket.SIO_KEEPALIVE_VALS', 1, create=True):
+            self.assertIsNotNone(enable_keepalive(Mock(), 10, 5))
+        with patch('socket.SIO_KEEPALIVE_VALS', None, create=True):
+            for platform in ('linux2', 'darwin', 'other'):
+                with patch('sys.platform', platform):
+                    self.assertIsNone(enable_keepalive(Mock(), 10, 5))
+
+    @patch('sys.platform', 'win32')
+    def test_find_executable(self):
+        with patch('os.path.isfile', Mock(return_value=True)):
+            self.assertEqual(find_executable('vim'), 'vim.exe')
+        with patch('os.path.isfile', Mock(return_value=False)):
+            self.assertIsNone(find_executable('vim'))
+        with patch('os.path.isfile', Mock(side_effect=[False, True])):
+            self.assertEqual(find_executable('vim', '/'), '/vim.exe')
+
 
 @patch('time.sleep', Mock())
 class TestRetrySleeper(unittest.TestCase):

tests/test_validator.py

@@ -33,11 +33,21 @@ config = {
     "etcd": {
         "hosts": "127.0.0.1:2379,127.0.0.1:2380"
     },
+    "etcd3": {
+        "url": "https://127.0.0.1:2379"
+    },
     "exhibitor": {
         "hosts": ["string"],
         "port": 4000,
         "pool_interval": 1000
     },
+    "raft": {
+        "self_addr": "127.0.0.1:2222",
+        "bind_addr": "0.0.0.0:2222",
+        "partner_addrs": ["127.0.0.1:2223", "127.0.0.1:2224"],
+        "data_dir": "/",
+        "password": "12345"
+    },
     "zookeeper": {
         "hosts":  "127.0.0.1:3379,127.0.0.1:3380"
     },
@@ -139,7 +149,7 @@ class TestValidator(unittest.TestCase):
     def test_complete_config(self, mock_out, mock_err):
         schema(config)
         output = mock_out.getvalue()
-        self.assertEqual(['postgresql.bin_dir'], parse_output(output))
+        self.assertEqual(['postgresql.bin_dir', 'raft.bind_addr', 'raft.self_addr'], parse_output(output))
 
     def test_bin_dir_is_file(self, mock_out, mock_err):
         files.append(config["postgresql"]["data_dir"])
@@ -151,8 +161,10 @@ class TestValidator(unittest.TestCase):
         schema(c)
         output = mock_out.getvalue()
         self.assertEqual(['etcd.hosts.1', 'etcd.hosts.2', 'kubernetes.pod_ip', 'postgresql.bin_dir',
-                          'postgresql.data_dir', 'restapi.connect_address'], parse_output(output))
+                          'postgresql.data_dir', 'raft.bind_addr', 'raft.self_addr',
+                          'restapi.connect_address'], parse_output(output))
 
+    @patch('socket.inet_pton', Mock(), create=True)
     def test_bin_dir_is_empty(self, mock_out, mock_err):
         directories.append(config["postgresql"]["data_dir"])
         directories.append(config["postgresql"]["bin_dir"])
@@ -166,8 +178,8 @@ class TestValidator(unittest.TestCase):
         with patch('patroni.validator.open', mock_open(read_data='9')):
             schema(c)
         output = mock_out.getvalue()
-        self.assertEqual(['consul.host', 'etcd.host', 'postgresql.bin_dir', 'postgresql.data_dir',
-                          'postgresql.listen', 'restapi.connect_address'], parse_output(output))
+        self.assertEqual(['consul.host', 'etcd.host', 'postgresql.bin_dir', 'postgresql.data_dir', 'postgresql.listen',
+                          'raft.bind_addr', 'raft.self_addr', 'restapi.connect_address'], parse_output(output))
 
     @patch('subprocess.check_output', Mock(return_value=b"postgres (PostgreSQL) 12.1"))
     def test_data_dir_contains_pg_version(self, mock_out, mock_err):
@@ -185,7 +197,7 @@ class TestValidator(unittest.TestCase):
         with patch('patroni.validator.open', mock_open(read_data='12')):
             schema(config)
         output = mock_out.getvalue()
-        self.assertEqual([], parse_output(output))
+        self.assertEqual(['raft.bind_addr', 'raft.self_addr'], parse_output(output))
 
     @patch('subprocess.check_output', Mock(return_value=b"postgres (PostgreSQL) 12.1"))
     def test_pg_version_missmatch(self, mock_out, mock_err):
@@ -200,7 +212,8 @@ class TestValidator(unittest.TestCase):
         with patch('patroni.validator.open', mock_open(read_data='11')):
             schema(c)
         output = mock_out.getvalue()
-        self.assertEqual(['etcd.hosts', 'postgresql.data_dir'], parse_output(output))
+        self.assertEqual(['etcd.hosts', 'postgresql.data_dir',
+                          'raft.bind_addr', 'raft.self_addr'], parse_output(output))
 
     @patch('subprocess.check_output', Mock(return_value=b"postgres (PostgreSQL) 12.1"))
     def test_pg_wal_doesnt_exist(self, mock_out, mock_err):
@@ -213,7 +226,7 @@ class TestValidator(unittest.TestCase):
         with patch('patroni.validator.open', mock_open(read_data='11')):
             schema(c)
         output = mock_out.getvalue()
-        self.assertEqual(['postgresql.data_dir'], parse_output(output))
+        self.assertEqual(['postgresql.data_dir', 'raft.bind_addr', 'raft.self_addr'], parse_output(output))
 
     def test_data_dir_is_empty_string(self, mock_out, mock_err):
         directories.append(config["postgresql"]["data_dir"])
@@ -225,5 +238,5 @@ class TestValidator(unittest.TestCase):
         c["postgresql"]["bin_dir"] = ""
         schema(c)
         output = mock_out.getvalue()
-        self.assertEqual(['kubernetes', 'postgresql.bin_dir',
-                          'postgresql.data_dir', 'postgresql.pg_hba'], parse_output(output))
+        self.assertEqual(['kubernetes', 'postgresql.bin_dir', 'postgresql.data_dir',
+                          'postgresql.pg_hba', 'raft.bind_addr', 'raft.self_addr'], parse_output(output))