Files
patroni/tests/test_rewind.py
T
ae0ede6944 Archive possibly missing WALs before rewind (#2384)
There is currently a risk to lose some WAL segments entirely in case
archive_mode was set to 'on' before a promotion and there are some WALs
with .ready files on the former leader we are trying to rewind. It happens
because of the pg_rewind's modus operandi: it simply syncs the content of
pg_wal directory of the old leader with the new leader's one. Including
deletion of all WALs that are not present on the current leader, regardless
their archive status on the former one. Thus, in case the new leader has
already recycled such files, we just remove them entirely.

In case archive_mode was set to 'always' and the .ready WALs are acrually
present in archive, it is for end user who writes the archive_command to
avoid overwritting and to properly test it.

Co-authored-by: Alexander Kukushkin <[email protected]>
2022-08-17 09:54:30 +02:00

305 lines
15 KiB
Python

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, psycopg_connect
class MockThread(object):
def __init__(self, target, args):
self._target = target
self._args = args
def start(self):
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('patroni.psycopg.connect', psycopg_connect)
class TestRewind(BaseTestPostgresql):
def setUp(self):
super(TestRewind, self).setUp()
self.r = Rewind(self.p)
def test_can_rewind(self):
with patch.object(Postgresql, 'controldata', Mock(return_value={'wal_log_hints setting': 'on'})):
self.assertTrue(self.r.can_rewind)
with patch('subprocess.call', Mock(return_value=1)):
self.assertFalse(self.r.can_rewind)
with patch('subprocess.call', side_effect=OSError):
self.assertFalse(self.r.can_rewind)
self.p.config._config['use_pg_rewind'] = False
self.assertFalse(self.r.can_rewind)
def test_pg_rewind(self):
r = {'user': '', 'host': '', 'port': '', 'database': '', 'password': ''}
with patch.object(Postgresql, 'major_version', PropertyMock(return_value=150000)),\
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):
self.r.trigger_check_diverged_lsn()
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',
'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=[(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_cancellable_call)
@patch.object(Postgresql, 'checkpoint', side_effect=['', '1'],)
@patch.object(Postgresql, 'stop', Mock(return_value=False))
@patch.object(Postgresql, 'start', Mock())
def test_execute(self, mock_checkpoint):
self.r.execute(self.leader)
with patch.object(Postgresql, 'major_version', PropertyMock(return_value=130000)):
self.r.execute(self.leader)
with patch.object(MockCursor, 'fetchone', Mock(side_effect=Exception)):
self.r.execute(self.leader)
with patch.object(Rewind, 'pg_rewind', Mock(return_value=False)):
mock_checkpoint.side_effect = ['1', '', '', '']
self.r.execute(self.leader)
self.r.execute(self.leader)
with patch.object(Rewind, 'check_leader_is_not_in_recovery', Mock(return_value=False)):
self.r.execute(self.leader)
self.p.config._config['remove_data_directory_on_rewind_failure'] = False
self.r.trigger_check_diverged_lsn()
self.r.execute(self.leader)
self.leader.member.data.update(version='1.5.7', checkpoint_after_promote=False, role='master')
self.assertIsNone(self.r.execute(self.leader))
del self.leader.member.data['checkpoint_after_promote']
with patch.object(Rewind, 'check_leader_is_not_in_recovery', Mock(return_value=False)):
self.assertIsNone(self.r.execute(self.leader))
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')
@patch.object(Rewind, '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.r.trigger_check_diverged_lsn()
with patch.object(MockCursor, 'fetchone', Mock(side_effect=[('', 3, '0/0'), ('', b'4\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('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=[('', 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=(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({})
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.path.isfile', Mock(return_value=True))
@patch('shutil.move', Mock(side_effect=OSError))
@patch('patroni.postgresql.rewind.logger.info')
def test_archive_ready_wals(self, mock_logger_info):
with patch('os.listdir', Mock(side_effect=OSError)), \
patch.object(Postgresql, 'get_guc_value', Mock(side_effect=['on', 'command %f'])):
self.r._archive_ready_wals()
mock_logger_info.assert_not_called()
# each assert_not_called() calls get_guc_value('archive_mode') + get_guc_value('archive_command')
get_guc_value_res = [
'', 'command %f',
'on', '',
]
with patch.object(Postgresql, 'get_guc_value', Mock(side_effect=get_guc_value_res)):
for _ in range(len(get_guc_value_res)//2):
self.r._archive_ready_wals()
mock_logger_info.assert_not_called()
with patch('os.listdir', Mock(return_value=['000000000000000000000000.ready'])):
# successful archive_command call
with patch.object(CancellableSubprocess, 'call', Mock(return_value=0)):
get_guc_value_res = [
'on', 'command %f',
'always', 'command %f',
]
with patch.object(Postgresql, 'get_guc_value', Mock(side_effect=get_guc_value_res)):
for _ in range(len(get_guc_value_res)//2):
self.r._archive_ready_wals()
mock_logger_info.assert_called_once()
self.assertEqual(('Trying to archive %s: %s',
'000000000000000000000000', 'command 000000000000000000000000'),
mock_logger_info.call_args[0])
mock_logger_info.reset_mock()
# failed archive_command call
with patch.object(CancellableSubprocess, 'call', Mock(return_value=1)):
with patch.object(Postgresql, 'get_guc_value', Mock(side_effect=['on', 'command %f'])):
self.r._archive_ready_wals()
self.assertEqual(('Trying to archive %s: %s',
'000000000000000000000000', 'command 000000000000000000000000'),
mock_logger_info.call_args_list[0][0])
self.assertEqual(('Failed to archive WAL segment %s', '000000000000000000000000'),
mock_logger_info.call_args_list[1][0])
mock_logger_info.reset_mock()
wal_files_to_skip = [
'000000000000000000000000.done',
'000000000000000000000001.partial.done',
'002.ready',
'U00000000000000000000001.ready',
]
with patch('os.listdir', Mock(return_value=wal_files_to_skip)):
self.r._archive_ready_wals()
mock_logger_info.assert_not_called()
@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')
@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_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
mock_checkpoint.side_effect = Exception
self.r.ensure_checkpoint_after_promote(Mock())