Files
patroni/tests/test_zookeeper.py
T
Alexander KukushkinandGitHub 00d125c512 Avoid unnecessary updates of the members ZNode. (#2115)
When deciding whether the ZNode should be updated we rely on the cached version of the cluster, which is updated only when members ZNodes are deleted/created or the `/status`, `/sync`, `/failover`, `/config`, or `/history` ZNodes are updated.

I.e. after the update of the current member ZNode succeeded the cache becomes stale and all further updates are always performed even if the value didn't change. In order to solve it, we introduce the new attribute in the Zookeeper class and will use it for memorizing the actual value and for later comparison.
2021-11-12 15:00:54 +01:00

260 lines
10 KiB
Python

import select
import six
import unittest
from kazoo.client import KazooClient, KazooState
from kazoo.exceptions import NoNodeError, NodeExistsError
from kazoo.handlers.threading import SequentialThreadingHandler
from kazoo.protocol.states import KeeperState, ZnodeStat
from mock import Mock, patch
from patroni.dcs.zookeeper import Leader, PatroniKazooClient,\
PatroniSequentialThreadingHandler, ZooKeeper, ZooKeeperError
class MockKazooClient(Mock):
leader = False
exists = True
def __init__(self, *args, **kwargs):
super(MockKazooClient, self).__init__()
self._session_timeout = 30000
@property
def client_id(self):
return (-1, '')
@staticmethod
def retry(func, *args, **kwargs):
return func(*args, **kwargs)
def get(self, path, watch=None):
if not isinstance(path, six.string_types):
raise TypeError("Invalid type for 'path' (string expected)")
if path == '/broken/status':
return (b'{', ZnodeStat(0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0))
elif path in ('/no_node', '/legacy/status'):
raise NoNodeError
elif '/members/' in path:
return (
b'postgres://repuser:rep-pass@localhost:5434/postgres?application_name=http://127.0.0.1:8009/patroni',
ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0 if self.exists else -1, 0, 0, 0)
)
elif path.endswith('/optime/leader'):
return (b'500', ZnodeStat(0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0))
elif path.endswith('/leader'):
if self.leader:
return (b'foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0))
return (b'foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
elif path.endswith('/initialize'):
return (b'foo', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
elif path.endswith('/status'):
return (b'{"optime":500,"slots":{"ls":1234567}}', ZnodeStat(0, 0, 0, 0, 0, 0, 0, -1, 0, 0, 0))
return (b'', ZnodeStat(0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0))
@staticmethod
def get_children(path, watch=None, include_data=False):
if not isinstance(path, six.string_types):
raise TypeError("Invalid type for 'path' (string expected)")
if path.startswith('/no_node'):
raise NoNodeError
elif path in ['/service/bla/', '/service/test/']:
return ['initialize', 'leader', 'members', 'optime', 'failover', 'sync']
return ['foo', 'bar', 'buzz']
def create(self, path, value=b"", acl=None, ephemeral=False, sequence=False, makepath=False):
if not isinstance(path, six.string_types):
raise TypeError("Invalid type for 'path' (string expected)")
if not isinstance(value, (six.binary_type,)):
raise TypeError("Invalid type for 'value' (must be a byte string)")
if b'Exception' in value:
raise Exception
if path.endswith('/initialize') or path == '/service/test/optime/leader':
raise Exception
elif b'retry' in value or (b'exists' in value and self.exists):
raise NodeExistsError
def create_async(self, path, value=b"", acl=None, ephemeral=False, sequence=False, makepath=False):
return self.create(path, value, acl, ephemeral, sequence, makepath) or Mock()
@staticmethod
def set(path, value, version=-1):
if not isinstance(path, six.string_types):
raise TypeError("Invalid type for 'path' (string expected)")
if not isinstance(value, (six.binary_type,)):
raise TypeError("Invalid type for 'value' (must be a byte string)")
if path == '/service/bla/optime/leader':
raise Exception
if path == '/service/test/members/bar' and b'retry' in value:
return
if path in ('/service/test/failover', '/service/test/config', '/service/test/sync'):
if b'Exception' in value:
raise Exception
elif value == b'ok':
return
raise NoNodeError
def set_async(self, path, value, version=-1):
return self.set(path, value, version) or Mock()
def delete(self, path, version=-1, recursive=False):
if not isinstance(path, six.string_types):
raise TypeError("Invalid type for 'path' (string expected)")
self.exists = False
if path == '/service/test/leader':
self.leader = True
raise Exception
elif path == '/service/test/members/buzz':
raise Exception
elif path.endswith('/') or path.endswith('/initialize') or path == '/service/test/members/bar':
raise NoNodeError
def delete_async(self, path, version=-1, recursive=False):
return self.delete(path, version, recursive) or Mock()
class TestPatroniSequentialThreadingHandler(unittest.TestCase):
def setUp(self):
self.handler = PatroniSequentialThreadingHandler(10)
@patch.object(SequentialThreadingHandler, 'create_connection', Mock())
def test_create_connection(self):
self.assertIsNotNone(self.handler.create_connection(()))
self.assertIsNotNone(self.handler.create_connection((), 40))
self.assertIsNotNone(self.handler.create_connection(timeout=40))
@patch.object(SequentialThreadingHandler, 'select', Mock(side_effect=ValueError))
def test_select(self):
self.assertRaises(select.error, self.handler.select)
class TestPatroniKazooClient(unittest.TestCase):
def test__call(self):
c = PatroniKazooClient()
with patch.object(KazooClient, '_call', Mock()):
self.assertIsNotNone(c._call(None, Mock()))
c._state = KeeperState.CONNECTING
self.assertFalse(c._call(None, Mock()))
class TestZooKeeper(unittest.TestCase):
@patch('patroni.dcs.zookeeper.PatroniKazooClient', MockKazooClient)
def setUp(self):
self.zk = ZooKeeper({'hosts': ['localhost:2181'], 'scope': 'test',
'name': 'foo', 'ttl': 30, 'retry_timeout': 10, 'loop_wait': 10})
def test_session_listener(self):
self.zk.session_listener(KazooState.SUSPENDED)
def test_reload_config(self):
self.zk.reload_config({'ttl': 20, 'retry_timeout': 10, 'loop_wait': 10})
self.zk.reload_config({'ttl': 20, 'retry_timeout': 10, 'loop_wait': 5})
def test_get_node(self):
self.assertIsNone(self.zk.get_node('/no_node'))
def test_get_children(self):
self.assertListEqual(self.zk.get_children('/no_node'), [])
def test__inner_load_cluster(self):
self.zk._base_path = self.zk._base_path.replace('test', 'bla')
self.zk._inner_load_cluster()
self.zk._base_path = self.zk._base_path = '/broken'
self.zk._inner_load_cluster()
self.zk._base_path = self.zk._base_path = '/legacy'
self.zk._inner_load_cluster()
self.zk._base_path = self.zk._base_path = '/no_node'
self.zk._inner_load_cluster()
def test_get_cluster(self):
self.assertRaises(ZooKeeperError, self.zk.get_cluster)
cluster = self.zk.get_cluster(True)
self.assertIsInstance(cluster.leader, Leader)
self.zk.touch_member({'foo': 'foo'})
self.zk._name = 'bar'
self.zk.status_watcher(None)
with patch.object(ZooKeeper, 'get_node', Mock(side_effect=Exception)):
self.zk.get_cluster()
cluster = self.zk.get_cluster()
self.assertEqual(cluster.last_lsn, 500)
def test_delete_leader(self):
self.assertTrue(self.zk.delete_leader())
def test_set_failover_value(self):
self.zk.set_failover_value('')
self.zk.set_failover_value('ok')
self.zk.set_failover_value('Exception')
def test_set_config_value(self):
self.zk.set_config_value('', 1)
self.zk.set_config_value('ok')
self.zk.set_config_value('Exception')
def test_initialize(self):
self.assertFalse(self.zk.initialize())
def test_cancel_initialization(self):
self.zk.cancel_initialization()
def test_touch_member(self):
self.zk._name = 'buzz'
self.zk.get_cluster()
self.zk.touch_member({'new': 'new'})
self.zk._name = 'bar'
self.zk.touch_member({'new': 'new'})
self.zk._name = 'na'
self.zk._client.exists = 1
self.zk.touch_member({'Exception': 'Exception'})
self.zk._name = 'bar'
self.zk.touch_member({'retry': 'retry'})
self.zk._fetch_cluster = True
self.zk.get_cluster()
self.zk.touch_member({'retry': 'retry'})
self.zk.touch_member({'conn_url': 'postgres://repuser:rep-pass@localhost:5434/postgres',
'api_url': 'http://127.0.0.1:8009/patroni'})
def test_take_leader(self):
self.zk.take_leader()
with patch.object(MockKazooClient, 'create', Mock(side_effect=Exception)):
self.zk.take_leader()
def test_update_leader(self):
self.assertTrue(self.zk.update_leader(12345))
def test_write_leader_optime(self):
self.zk.last_lsn = '0'
self.zk.write_leader_optime('1')
with patch.object(MockKazooClient, 'create_async', Mock()):
self.zk.write_leader_optime('1')
with patch.object(MockKazooClient, 'set_async', Mock()):
self.zk.write_leader_optime('2')
self.zk._base_path = self.zk._base_path.replace('test', 'bla')
self.zk.write_leader_optime('3')
def test_delete_cluster(self):
self.assertTrue(self.zk.delete_cluster())
def test_watch(self):
self.zk.watch(None, 0)
self.zk.event.isSet = Mock(return_value=True)
self.zk._fetch_status = False
self.zk.watch(None, 0)
def test__kazoo_connect(self):
self.zk._client._retry.deadline = 1
self.zk._orig_kazoo_connect = Mock(return_value=(0, 0))
self.zk._kazoo_connect(None, None)
def test_sync_state(self):
self.zk.set_sync_state_value('')
self.zk.set_sync_state_value('ok')
self.zk.set_sync_state_value('Exception')
self.zk.delete_sync_state()
def test_set_history_value(self):
self.zk.set_history_value('{}')