class ZKClient(object):
def __init__(self,
zk_hosts,
local_port,
local_host=None,
server_info_path='/crawlers'):
self.zk_hosts = zk_hosts
self.local_host = local_host
if not self.local_host:
self.local_host = get_local_host()
self.server_info_path = server_info_path
self.server_info_znode = '{server_info_path}/{ip}:{port}'.format(
server_info_path=server_info_path,
ip=self.local_host,
port=local_port)
self.connect_zk()
def connect_zk(self):
self.zk = KazooClient(hosts=self.zk_hosts)
self.zk.add_listener(self.state_listener)
self.zk.start()
def update_heartbeat(self):
def callback(async_stat):
stat = async_stat.get()
if stat:
_ = self.zk.set_async(self.server_info_znode, ts)
else:
_ = self.zk.create_async(self.server_info_znode,
ts,
ephemeral=True,
makepath=True)
ts = str(int(time.time()))
async_stat = self.zk.exists_async(self.server_info_znode, watch=None)
async_stat.rawlink(callback)
def state_listener(self, state):
if state == KazooState.LOST:
# Register somewhere that the session was lost
pass
elif state == KazooState.SUSPENDED:
# Handle being disconnected from Zookeeper
pass
else:
self.update_heartbeat()
def add_watcher(self, request_handler):
@self.zk.DataWatch(ZOO_CONFIG_PROXY_PATH)
def proxy_change(data, stat):
run_in_thread(request_handler.config_proxy_via_zookeeper, data)
def close(self):
self.zk.stop()
class NodeMonitor:
STATIC_NODE_ID = 0
global t
def __init__(self):
self.zk = None
self.SERVER_IP_AND_PORT = "localhost:2181"
self.NODE_ID = str(NodeMonitor.STATIC_NODE_ID)
NodeMonitor.STATIC_NODE_ID += 1
def start_zk(self):
self.zk = KazooClient(hosts=self.SERVER_IP_AND_PORT)
self.zk.add_listener(self._connection_listener)
self.zk.start();
self.zk.ensure_path("/monitorData/"+ self.NODE_ID)
def start_update_info(self):
t = threading.Timer(0.0, self._update_info)
t.start()
def _update_info_once(self):
cmi = CollectMachineInfo()
async_obj = self.zk.set_async("/monitorData/"+ self.NODE_ID, (cmi.collectInfo()).encode(encoding="utf-8"))
async_obj.rawlink(self._update_info_callback)
def _connection_listener(self, state):
if state == KazooState.LOST:
print "connection lost, going to connect again"
self.start_zk();
elif state == KazooState.SUSPENDED:
print "suspended"
else:
print "connected ok"
def _update_info_callback(self, async_obj):
try:
print "update success"
except (ConnectionLossException, NoAuthException):
print "exception!"
def _update_info(self):
print "begin to update"
self._update_info_once()
t = threading.Timer(5.0, self._update_info)
t.start()
class ZooKeeper(AbstractDCS):
def __init__(self, config):
super(ZooKeeper, self).__init__(config)
hosts = config.get('hosts', [])
if isinstance(hosts, list):
hosts = ','.join(hosts)
self._client = KazooClient(hosts, handler=PatroniSequentialThreadingHandler(config['retry_timeout']),
timeout=config['ttl'], connection_retry={'max_delay': 1, 'max_tries': -1},
command_retry={'deadline': config['retry_timeout'], 'max_delay': 1, 'max_tries': -1})
self._client.add_listener(self.session_listener)
self._my_member_data = None
self._fetch_cluster = True
self._last_leader_operation = 0
self._orig_kazoo_connect = self._client._connection._connect
self._client._connection._connect = self._kazoo_connect
self._client.start()
def _kazoo_connect(self, host, port):
"""Kazoo is using Ping's to determine health of connection to zookeeper. If there is no
response on Ping after Ping interval (1/2 from read_timeout) it will consider current
connection dead and try to connect to another node. Without this "magic" it was taking
up to 2/3 from session timeout (ttl) to figure out that connection was dead and we had
only small time for reconnect and retry.
This method is needed to return different value of read_timeout, which is not calculated
from negotiated session timeout but from value of `loop_wait`. And it is 2 sec smaller
than loop_wait, because we can spend up to 2 seconds when calling `touch_member()` and
`write_leader_optime()` methods, which also may hang..."""
ret = self._orig_kazoo_connect(host, port)
return max(self.loop_wait - 2, 2)*1000, ret[1]
def session_listener(self, state):
if state in [KazooState.SUSPENDED, KazooState.LOST]:
self.cluster_watcher(None)
def cluster_watcher(self, event):
self._fetch_cluster = True
self.event.set()
def reload_config(self, config):
self.set_retry_timeout(config['retry_timeout'])
loop_wait = config['loop_wait']
loop_wait_changed = self._loop_wait != loop_wait
self._loop_wait = loop_wait
self._client.handler.set_connect_timeout(loop_wait)
# We need to reestablish connection to zookeeper if we want to change
# read_timeout (and Ping interval respectively), because read_timeout
# is calculated in `_kazoo_connect` method. If we are changing ttl at
# 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:
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)."""
if self._client._session_timeout != ttl:
self._client._session_timeout = ttl
self._client.restart()
return True
def set_retry_timeout(self, retry_timeout):
self._client._retry.deadline = retry_timeout
def get_node(self, key, watch=None):
try:
ret = self._client.get(key, watch)
return (ret[0].decode('utf-8'), ret[1])
except NoNodeError:
return None
@staticmethod
def member(name, value, znode):
return Member.from_node(znode.version, name, znode.ephemeralOwner, value)
def get_children(self, key, watch=None):
try:
return self._client.get_children(key, watch)
except NoNodeError:
return []
def load_members(self):
members = []
for member in self.get_children(self.members_path, self.cluster_watcher):
data = self.get_node(self.members_path + member)
if data is not None:
members.append(self.member(member, *data))
return members
def _inner_load_cluster(self):
self._fetch_cluster = False
self.event.clear()
nodes = set(self.get_children(self.client_path(''), self.cluster_watcher))
if not nodes:
self._fetch_cluster = True
# get initialize flag
initialize = (self.get_node(self.initialize_path) or [None])[0] if self._INITIALIZE in nodes else None
# get global dynamic configuration
config = self.get_node(self.config_path, watch=self.cluster_watcher) if self._CONFIG in nodes else None
config = config and ClusterConfig.from_node(config[1].version, config[0], config[1].mzxid)
# get list of members
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
if leader:
client_id = self._client.client_id
if leader[0] == self._name and client_id is not None and client_id[0] != leader[1].ephemeralOwner:
logger.info('I am leader but not owner of the session. Removing leader node')
self._client.delete(self.leader_path)
leader = None
if leader:
member = Member(-1, leader[0], None, {})
member = ([m for m in members if m.name == leader[0]] or [member])[0]
leader = Leader(leader[1].version, leader[1].ephemeralOwner, member)
self._fetch_cluster = member.index == -1
# 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])
# get last leader operation
optime = self.get_node(self.leader_optime_path) if self._OPTIME in nodes and self._fetch_cluster else None
self._last_leader_operation = 0 if optime is None else int(optime[0])
self._cluster = Cluster(initialize, config, leader, self._last_leader_operation, members, failover)
def _load_cluster(self):
if self._fetch_cluster or self._cluster is None:
try:
self._client.retry(self._inner_load_cluster)
except Exception:
logger.exception('get_cluster')
self.cluster_watcher(None)
raise ZooKeeperError('ZooKeeper in not responding properly')
def _create(self, path, value, **kwargs):
try:
self._client.retry(self._client.create, path, value.encode('utf-8'), **kwargs)
return True
except:
return False
def attempt_to_acquire_leader(self, permanent=False):
ret = self._create(self.leader_path, self._name, makepath=True, ephemeral=not permanent)
if not ret:
logger.info('Could not take out TTL lock')
return ret
def set_failover_value(self, value, index=None):
try:
self._client.retry(self._client.set, self.failover_path, value.encode('utf-8'), version=index or -1)
return True
except NoNodeError:
return value == '' or (index is None and self._create(self.failover_path, value))
except:
logging.exception('set_failover_value')
return False
def set_config_value(self, value, index=None):
try:
self._client.retry(self._client.set, self.config_path, value.encode('utf-8'), version=index or -1)
return True
except NoNodeError:
return index is None and self._create(self.config_path, value)
except Exception:
logging.exception('set_config_value')
return False
def initialize(self, create_new=True, sysid=""):
return self._create(self.initialize_path, sysid, makepath=True) if create_new \
else self._client.retry(self._client.set, self.initialize_path, sysid.encode("utf-8"))
def touch_member(self, data, ttl=None, permanent=False):
cluster = self.cluster
member = cluster and ([m for m in cluster.members if m.name == self._name] or [None])[0]
data = data.encode('utf-8')
if member and self._client.client_id is not None and member.session != self._client.client_id[0]:
try:
self._client.delete_async(self.member_path).get(timeout=1)
except NoNodeError:
pass
except:
return False
member = None
if member:
if data == self._my_member_data:
return True
else:
try:
self._client.create_async(self.member_path, data, makepath=True, ephemeral=not permanent).get(timeout=1)
self._my_member_data = data
return True
except Exception as e:
if not isinstance(e, NodeExistsError):
logger.exception('touch_member')
return False
try:
self._client.set_async(self.member_path, data).get(timeout=1)
self._my_member_data = data
return True
except:
logger.exception('touch_member')
return False
def take_leader(self):
return self.attempt_to_acquire_leader()
def write_leader_optime(self, last_operation):
last_operation = last_operation.encode('utf-8')
if last_operation != self._last_leader_operation:
try:
self._client.set_async(self.leader_optime_path, last_operation).get(timeout=1)
self._last_leader_operation = last_operation
except NoNodeError:
try:
self._client.create_async(self.leader_optime_path, last_operation, makepath=True).get(timeout=1)
self._last_leader_operation = last_operation
except:
logger.exception('Failed to create %s', self.leader_optime_path)
except:
logger.exception('Failed to update %s', self.leader_optime_path)
def update_leader(self):
return True
def delete_leader(self):
self._client.restart()
self._my_member_data = None
return True
def _cancel_initialization(self):
node = self.get_node(self.initialize_path)
if node:
self._client.delete(self.initialize_path, version=node[1].version)
def cancel_initialization(self):
try:
self._client.retry(self._cancel_initialization)
except:
logger.exception("Unable to delete initialize key")
def delete_cluster(self):
try:
return self._client.retry(self._client.delete, self.client_path(''), recursive=True)
except NoNodeError:
return True
def watch(self, timeout):
if super(ZooKeeper, self).watch(timeout):
self._fetch_cluster = True
return self._fetch_cluster
class ZooKeeper(AbstractDCS):
def __init__(self, config):
super(ZooKeeper, self).__init__(config)
hosts = config.get('hosts', [])
if isinstance(hosts, list):
hosts = ','.join(hosts)
mapping = {
'use_ssl': 'use_ssl',
'verify': 'verify_certs',
'cacert': 'ca',
'cert': 'certfile',
'key': 'keyfile',
'key_password': '******'
}
kwargs = {v: config[k] for k, v in mapping.items() if k in config}
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),
**kwargs)
self._client.add_listener(self.session_listener)
self._fetch_cluster = True
self._fetch_optime = True
self._orig_kazoo_connect = self._client._connection._connect
self._client._connection._connect = self._kazoo_connect
self._client.start()
def _kazoo_connect(self, *args):
"""Kazoo is using Ping's to determine health of connection to zookeeper. If there is no
response on Ping after Ping interval (1/2 from read_timeout) it will consider current
connection dead and try to connect to another node. Without this "magic" it was taking
up to 2/3 from session timeout (ttl) to figure out that connection was dead and we had
only small time for reconnect and retry.
This method is needed to return different value of read_timeout, which is not calculated
from negotiated session timeout but from value of `loop_wait`. And it is 2 sec smaller
than loop_wait, because we can spend up to 2 seconds when calling `touch_member()` and
`write_leader_optime()` methods, which also may hang..."""
ret = self._orig_kazoo_connect(*args)
return max(self.loop_wait - 2, 2) * 1000, ret[1]
def session_listener(self, state):
if state in [KazooState.SUSPENDED, KazooState.LOST]:
self.cluster_watcher(None)
def optime_watcher(self, event):
self._fetch_optime = True
self.event.set()
def cluster_watcher(self, event):
self._fetch_cluster = True
self.optime_watcher(event)
def reload_config(self, config):
self.set_retry_timeout(config['retry_timeout'])
loop_wait = config['loop_wait']
loop_wait_changed = self._loop_wait != loop_wait
self._loop_wait = loop_wait
self._client.handler.set_connect_timeout(loop_wait)
# We need to reestablish connection to zookeeper if we want to change
# read_timeout (and Ping interval respectively), because read_timeout
# is calculated in `_kazoo_connect` method. If we are changing ttl at
# 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:
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)."""
if self._client._session_timeout != ttl:
self._client._session_timeout = ttl
self._client.restart()
return True
@property
def ttl(self):
return self._client._session_timeout
def set_retry_timeout(self, retry_timeout):
retry = self._client.retry if isinstance(
self._client.retry, KazooRetry) else self._client._retry
retry.deadline = retry_timeout
def get_node(self, key, watch=None):
try:
ret = self._client.get(key, watch)
return (ret[0].decode('utf-8'), ret[1])
except NoNodeError:
return None
def get_leader_optime(self, leader):
watch = self.optime_watcher if not leader or leader.name != self._name else None
optime = self.get_node(self.leader_optime_path, watch)
self._fetch_optime = False
return optime and int(optime[0]) or 0
@staticmethod
def member(name, value, znode):
return Member.from_node(znode.version, name, znode.ephemeralOwner,
value)
def get_children(self, key, watch=None):
try:
return self._client.get_children(key, watch)
except NoNodeError:
return []
def load_members(self, sync_standby):
members = []
for member in self.get_children(self.members_path,
self.cluster_watcher):
watch = member in sync_standby and self.cluster_watcher or None
data = self.get_node(self.members_path + member, watch)
if data is not None:
members.append(self.member(member, *data))
return members
def _inner_load_cluster(self):
self._fetch_cluster = False
self.event.clear()
nodes = set(
self.get_children(self.client_path(''), self.cluster_watcher))
if not nodes:
self._fetch_cluster = True
# get initialize flag
initialize = (self.get_node(self.initialize_path)
or [None])[0] if self._INITIALIZE in nodes else None
# get global dynamic configuration
config = self.get_node(
self.config_path,
watch=self.cluster_watcher) if self._CONFIG in nodes else None
config = config and ClusterConfig.from_node(config[1].version,
config[0], config[1].mzxid)
# get timeline history
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 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.members or []
members = self.load_members(
sync_standby) if self._MEMBERS[:-1] in nodes else []
# get leader
leader = self.get_node(
self.leader_path) if self._LEADER in nodes else None
if leader:
client_id = self._client.client_id
if not self._ctl and leader[0] == self._name and client_id is not None \
and client_id[0] != leader[1].ephemeralOwner:
logger.info(
'I am leader but not owner of the session. Removing leader node'
)
self._client.delete(self.leader_path)
leader = None
if leader:
member = Member(-1, leader[0], None, {})
member = ([m for m in members if m.name == leader[0]]
or [member])[0]
leader = Leader(leader[1].version, leader[1].ephemeralOwner,
member)
self._fetch_cluster = member.index == -1
# get last leader operation
last_leader_operation = self._OPTIME in nodes and self.get_leader_optime(
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)
def _load_cluster(self):
cluster = self.cluster
if self._fetch_cluster or cluster is None:
try:
cluster = self._client.retry(self._inner_load_cluster)
except Exception:
logger.exception('get_cluster')
self.cluster_watcher(None)
raise ZooKeeperError('ZooKeeper in not responding properly')
# Optime ZNode was updated or doesn't exist and we are not leader
elif (self._fetch_optime and not self._fetch_cluster or not cluster.last_leader_operation) and\
not (cluster.leader and cluster.leader.name == self._name):
try:
optime = self.get_leader_optime(cluster.leader)
cluster = Cluster(cluster.initialize, cluster.config,
cluster.leader, optime, cluster.members,
cluster.failover, cluster.sync,
cluster.history)
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:
self._client.retry(self._client.create,
path,
value,
makepath=True,
ephemeral=ephemeral)
else:
self._client.create_async(path,
value,
makepath=True,
ephemeral=ephemeral).get(timeout=1)
return True
except Exception:
logger.exception('Failed to create %s', path)
return False
def attempt_to_acquire_leader(self, permanent=False):
ret = self._create(self.leader_path,
self._name.encode('utf-8'),
retry=True,
ephemeral=not permanent)
if not ret:
logger.info('Could not take out TTL lock')
return ret
def _set_or_create(self,
key,
value,
index=None,
retry=False,
do_not_create_empty=False):
value = value.encode('utf-8')
try:
if retry:
self._client.retry(self._client.set,
key,
value,
version=index or -1)
else:
self._client.set_async(key, value, version=index
or -1).get(timeout=1)
return True
except NoNodeError:
if do_not_create_empty and not value:
return True
elif index is None:
return self._create(key, value, retry)
else:
return False
except Exception:
logger.exception('Failed to update %s', key)
return False
def set_failover_value(self, value, index=None):
return self._set_or_create(self.failover_path, value, index)
def set_config_value(self, value, index=None):
return self._set_or_create(self.config_path, value, index, retry=True)
def initialize(self, create_new=True, sysid=""):
sysid = sysid.encode('utf-8')
return self._create(self.initialize_path, sysid, retry=True) if create_new \
else self._client.retry(self._client.set, self.initialize_path, sysid)
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')
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'))):
try:
self._client.delete_async(self.member_path).get(timeout=1)
except NoNodeError:
pass
except Exception:
return False
member = None
if member:
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)
return True
except Exception as e:
if not isinstance(e, NodeExistsError):
logger.exception('touch_member')
return False
try:
self._client.set_async(self.member_path,
encoded_data).get(timeout=1)
return True
except Exception:
logger.exception('touch_member')
return False
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 _update_leader(self):
return True
def _delete_leader(self):
self._client.restart()
return True
def _cancel_initialization(self):
node = self.get_node(self.initialize_path)
if node:
self._client.delete(self.initialize_path, version=node[1].version)
def cancel_initialization(self):
try:
self._client.retry(self._cancel_initialization)
except Exception:
logger.exception("Unable to delete initialize key")
def delete_cluster(self):
try:
return self._client.retry(self._client.delete,
self.client_path(''),
recursive=True)
except NoNodeError:
return True
def set_history_value(self, value):
return self._set_or_create(self.history_path, value)
def set_sync_state_value(self, value, index=None):
return self._set_or_create(self.sync_path,
value,
index,
retry=True,
do_not_create_empty=True)
def delete_sync_state(self, index=None):
return self.set_sync_state_value("{}", index)
def watch(self, leader_index, timeout):
if super(ZooKeeper, self).watch(leader_index,
timeout) and not self._fetch_optime:
self._fetch_cluster = True
return self._fetch_cluster
if MACHINE_STRING not in children:
create_service_async_job = zk.create_async(
path=ROOT_PATH + SERVICE_PATH + '/' + MACHINE_STRING,
value=MACHINE_AVAIL_SERVICE,
ephemeral=True)
create_service_async_job.rawlink(create_path_async_callback)
else:
print "PATH existed."
except (ConnectionLossException, NoAuthException):
logger.error('Can not connect.')
sys.exit(1)
if __name__ == '__main__':
zk.start()
zk.add_listener(my_listener)
get_children_async_obj = zk.get_children_async(ROOT_PATH + SERVICE_PATH)
get_children_async_obj.rawlink(get_service_path_children_callback)
while True:
input_data = raw_input()
if input_data != foredata:
set_value_async = zk.set_async(path=ROOT_PATH + SERVICE_PATH +
'/' + MACHINE_STRING,
value=input_data)
set_value_async.rawlink(
partial(set_service_child_value_callback, input_data))
if input_data == 'exit':
print 'Exit'
sys.exit(1)
time.sleep(5)
class Zookeeper:
def __init__(self, hosts):
self.zk = KazooClient(hosts=hosts,
handler=SequentialGeventHandler(),
logger=logger)
# returns immediately
event = self.zk.start_async()
# Wait for 30 seconds and see if we're connected
event.wait(timeout=30)
try:
if not self.zk.connected:
# Not connected, stop trying to connect
self.zk.stop()
except (ConnectionLossException, NoAuthException) as error:
raise error
except Exception as error:
raise error
@coroutine
def get_children(self, node):
try:
children = self.zk.get_children_async(node)
raise Return(children.get())
except Exception as error:
raise error
@coroutine
def get_node(self, node):
try:
data = self.zk.get_async(node)
raise Return(data.get())
except Exception as error:
raise error
@coroutine
def check_path_exist(self, path):
try:
result = self.zk.exists(path)
if result:
raise Return(True)
else:
raise Return(False)
except Exception as error:
raise error
@coroutine
def create_path(self, path):
try:
result = self.zk.ensure_path_async(path)
raise Return(result.get())
except Exception as error:
raise error
@coroutine
def create_node(self, path, value):
try:
result = self.zk.create_async(path=path,
value=value,
acl=None,
ephemeral=True)
raise Return(result.get())
except Exception as error:
raise error
@coroutine
def update_node(self, path, value, version=-1):
try:
result = self.zk.set_async(path, value, version)
raise Return(result.get())
except Exception as error:
raise error
@coroutine
def update_node(self, path, value, version=-1):
try:
result = self.zk.set_async(path, value, version)
raise Return(result.get())
except Exception as error:
raise error
@coroutine
def del_node(self, node):
try:
node_info = self.zk.delete_async(node)
raise Return(node_info.get())
except Exception as error:
raise error
def close(self):
self.zk.stop()
class NodeMonitor:
global t
def __init__(self, argv1):
# the client net card eth0
self.static_net_card = 'eth0'
self.static_path_for_data_3_second_once_time = "/monitorData"
self.static_path_for_data_10_second_once_time = "/monitorDataProcessInfo"
self.static_path_for_data_just_one_time = "/monitorDataJustOneTime"
self.is_server = False
if argv1 == '-server':
self.is_server = True
self._set_up_server_path()
# use mac address to divide different virtual machine
self.STATIC_NODE_IP_ADDRESS = get_ip_address(self.static_net_card)
self.STATIC_NODE_MAC_ADDRESS = get_mac_address()
self.zk = None
#self.SERVER_IP_AND_PORT = "127.0.0.1:2181"
self.SERVER_IP_AND_PORT = "172.18.229.251:2181"
#STATIC_NODE_MAC_ADDRESS = get_mac_address()
self.NODE_ID = str(self.STATIC_NODE_IP_ADDRESS)
self.NODE_ID_PATH = '/' + self.NODE_ID
#print self.NODE_ID
def _set_up_server_path(self):
# the server net card eth1
self.static_net_card = 'eth1'
#self.static_path_for_data_3_second_once_time += "Server"
#self.static_path_for_data_10_second_once_time += "Server"
#self.static_path_for_data_just_one_time += "Server"
def start_zk(self):
#self.zk = KazooClient("127.0.0.1:2181")
self.zk = KazooClient("172.18.229.251:2181")
self.zk.add_listener(self._connection_listener)
#self.zk.start();
try:
self.zk.start()
#print "zk-start-try"
except (KazooTimeoutError):
print "connect fail, going to reconnect"
time.sleep(5.0)
self.start_zk()
self.zk.ensure_path(self.static_path_for_data_3_second_once_time
+ self.NODE_ID_PATH)
def start_update_info(self):
t = threading.Timer(0.0, self._update_info)
t.start()
t2 = threading.Timer(0.0, self._update_info_10_second_once_time)
t2.start()
def _update_info_once(self):
cmi = CollectMachineInfo(self.is_server)
#print self.NODE_ID
async_obj = self.zk.set_async(self.static_path_for_data_3_second_once_time
+ self.NODE_ID_PATH, (cmi.collectInfo()).encode(encoding="utf-8"))
async_obj.rawlink(self._update_info_callback)
def _connection_listener(self, state):
if state == KazooState.LOST:
print "connection lost, going to connect again"
self.start_zk();
elif state == KazooState.SUSPENDED:
print "suspended"
else:
#print "connected ok"
return
def _update_info_callback(self, async_obj):
try:
#print "update success"
return
except (ConnectionLossException, NoAuthException):
print "exception!"
def _update_info(self):
#print "begin to update"
self.zk.ensure_path(self.static_path_for_data_3_second_once_time
+ self.NODE_ID_PATH)
self._update_info_once()
t = threading.Timer(1.0, self._update_info)
t.start()
def _update_info_10_second_once_time(self):
self.zk.ensure_path(self.static_path_for_data_10_second_once_time
+ self.NODE_ID_PATH)
self._update_info_once_10_second()
t = threading.Timer(10.0, self._update_info_10_second_once_time)
t.start()
def _update_info_once_10_second(self):
cpi = CollectProcessInfo()
#print cpi
#print self.NODE_ID
async_obj = self.zk.set_async(self.static_path_for_data_10_second_once_time
+ self.NODE_ID_PATH, (cpi._get_process_info()) )
async_obj.rawlink(self._update_info_callback)
def _update_info_just_one_time(self):
#print "just one time to update"
self.zk.ensure_path(self.static_path_for_data_just_one_time
+ self.NODE_ID_PATH)
cmi_just_one_time = CollectMachineInfo(self.is_server)
async_obj_just_one_time = self.zk.set_async(self.static_path_for_data_just_one_time
+ self.NODE_ID_PATH,
(cmi_just_one_time.collectInfoJustOneTime()).encode(encoding="utf-8"))
async_obj_just_one_time.rawlink(self._update_info_callback)
class Coordinator(object):
def __init__(self, zkhosts, root=NODE_HQ_ROOT, alivenode="alive", readonly=False, role=None):
"""zkhosts: a string or a list. list will be ','.join-ed into a string.
root: root node path (any parents must exist, if any)
"""
self.LOGGER = logging.getLogger("hq.zkcoord")
if not isinstance(zkhosts, basestring):
zkhosts = ",".join(zkhosts)
self.zkhosts = zkhosts
self.ROOT = root
self.alivenode = alivenode
self.readonly = readonly
self.nodename = os.uname()[1]
self.NODE_SERVERS = self.ROOT + "/servers"
self.NODE_ME = self.NODE_SERVERS + "/" + self.nodename
self.NODE_MYJOBS = self.NODE_ME + "/jobs"
self.NODE_GJOBS = self.ROOT + "/jobs"
self.__listeners = {}
self.jobs = {}
self.zh = None
self.zstate = None
self._connect()
def _connect(self):
try:
if self.zh:
self.zh.stop()
self.LOGGER.debug("connecting to %s", self.zkhosts)
self.zh = KazooClient(hosts=self.zkhosts)
self.zh.add_listener(self.__watcher)
# this will wait until connection is established.
self.zh.start()
except ZookeeperError as ex:
self.zh = None
self.zkerror = ex
def _initialize(self):
if not self.readonly:
if self.zstate is None:
self.zh.ensure_path(self.NODE_SERVERS)
self.zh.ensure_path(self.NODE_GJOBS)
self.publish_alive()
if not self.zh.exists(self.NODE_ME):
self.zh.create(self.NODE_ME, "")
if not self.zh.exists(self.NODE_MYJOBS):
self.zh.acreate(self.NODE_MYJOBS)
# setup notifications
self.zh.get_children(self.NODE_SERVERS, self.__servers_watcher)
self.zh.get_children(self.NODE_GJOBS, self.__jobs_watcher)
def __watcher(self, state):
# client level callback method. this method should not block.
if state == KazooState.LOST:
# session expiration
self.zstate = state
elif state == KazooState.SUSPENDED:
# disconnected, session is still alive
self.zstate = state
else:
# (re)connected
self.LOGGER.debug("connected")
self.zh.handler.spawn(self._initialize)
self.zstate = state
def get_status_text(self):
return self.zkerror
def create(self, path, data=""): # , perm=PERM_WORLD, flags=''):
return self.zh.create(path, data)
def acreate(self, path, data=""): # , perm=PERM_WORLD, flags=''):
return self.zh.acreate(path, data)
def exists(self, path):
return self.zh.exists(path)
def delete(self, path):
try:
return self.zh.delete(path)
except NoNodeError as ex:
pass
def get_children(self, path, watch=None):
return self.zh.get_children(path, watch=watch)
def __servers_watcher(self, zh, evtype, state, path):
"""called when HQ servers are added / dropped."""
try:
ch = self.get_children(self.NODE_SERVERS, watch=self.__servers_watcher)
self.LOGGER.info("servers added/removed:%s", str(ch))
self.fire_event("serverschanged")
except ZookeeperError as ex:
self.LOGGER.warn("zk.get_children(%r) failed", self.NODE_SERVERS, exc_info=1)
def __jobs_watcher(self, zh, evtype, state, path):
"""called when jobs are added / dropped."""
try:
self.LOGGER.info("%s children changed", self.NODE_GJOBS)
ch = self.get_children(self.NODE_GJOBS, watch=self.__jobs_watcher)
self.fire_event("jobschanged")
except ZooKeeperError as ex:
self.LOGGER.warn("get_children(%r) failed", self.NODE_GJOBS, exc_info=1)
def publish_alive(self):
node_alive = self.NODE_ME + "/" + self.alivenode
self.zh.create_async(node_alive, ephemeral=True)
def publish_job(self, job):
"""job: hq.CrawlJob"""
ju = self.jobs.get(job)
# update 10 minutes interval
if ju is None or ju < time.time() - 10 * 60:
NODE_MYJOB = self.NODE_MYJOBS + "/" + job.jobname
def set_complete(a):
# print >>sys.stderr, "aset completed: %s" % str(args)
if a.exception == NoNodeError:
# node does not exist yet - create anew
self.zh.create_async(NODE_MYJOB, "")
try:
a = self.zh.set_async(NODE_MYJOB, "")
a.rawlink(set_complete)
except:
self.LOGGER.warn("aset failed", exc_info=1)
pass
node2 = self.NODE_GJOBS + "/" + job.jobname
self.zh.create_async(node2)
self.zh.create_async("{}/{}/{}".format(self.NODE_GJOBS, job.jobname, self.nodename), ephemeral=True)
self.jobs[job] = time.time()
def publish_client(self, job, client):
pass
def get_servers(self):
return self.zh.get_children(self.NODE_SERVERS)
def get_server_job(self, server, job):
p = self.NODE_SERVERS + "/" + server + "/jobs/" + job
j = dict()
try:
nodeval = self.zh.get(p)
attr = nodeval[1]
j["ts"] = attr.mtime / 1000.0
except NoNodeError as ex:
j["ts"] = 0
return j
def get_status_of(self, server=None, jobs=None):
if self.zh is None:
return None
server = server or self.nodename
status = dict(name=server)
try:
node = self.zh.get(self.NODE_SERVERS + "/" + server + "/alive")
status["alive"] = node[1]
except NoNodeError as ex:
status["alive"] = False
jobspath = self.NODE_SERVERS + "/" + server + "/jobs"
if jobs is None:
try:
jobs = self.get_children(jobspath)
except NoNodeError:
jobs = []
elif isinstance(jobs, basestring):
jobs = [jobs]
status["jobs"] = []
for j in jobs:
jobj = self.get_server_job(server, j)
jobj["name"] = j
status["jobs"].append(jobj)
return status
def get_servers_status(self):
return [self.get_status_of(server) for server in self.get_servers()]
def get_job_servers(self, jobname):
"""return a map of integer identifier to server name, which
is configured for the job jobname.
"""
p = self.NODE_GJOBS + "/" + jobname + "/servers"
try:
svids = self.get_children(p)
except NoNodeError as ex:
return {}
servers = {}
for name in svids:
try:
svid = int(name)
except:
continue
nodevals = self.zh.get(p + "/" + str(svid))
if nodevals[0]:
servers[svid] = nodevals[0]
return servers
def get_job_servers2(self, jobname):
"""returns servers for job "jobname", including those active
but not registered at jobs/JOBNAME/servers. elements of returned
list are dict with svid and name keys. svid key only exists for
those registered for the "jobname".
"""
servers = [dict(svid=svid, name=name) for svid, name in self.get_job_servers(jobname).items()]
regservers = set(s["name"] for s in servers)
try:
p = self.NODE_SERVERS
ss = self.get_children(self.NODE_SERVERS)
for s in ss:
if s in regservers:
continue
if not self.is_server_alive(s):
continue
p = self.NODE_SERVERS + "/" + s + "/jobs/" + jobname
if self.exists(p):
servers.append(dict(name=s))
except ZookeeperError as ex:
self.LOGGER.debug("zookeeper access failed", exc_info=1)
return servers
def add_job_server(self, job, server):
pass
def delete_job_server(self, job, server):
jobservers = dict((v, k) for k, v in self.get_job_servers(job).items())
if server in jobservers:
p = self.NODE_GJOBS + "/" + job + "/servers/" + jobservers[server]
self.delete(p)
p = self.NODE_SERVERS + "/" + server + "/jobs/" + job
# assumption: there's no child under the server/job node.
try:
self.delete(p)
except NoNodeError as ex:
pass
except NotEmptyException as ex:
# XXX
pass
def is_server_alive(self, server):
p = self.NODE_SERVERS + "/" + server + "/alive"
return self.exists(p)
def add_listener(self, ev, listener):
if not isinstance(ev, basestring):
raise ValueError, "ev must be a string"
ll = self.__listeners.get(ev)
if not ll:
self.__listeners[ev] = set((listener,))
else:
ll.add(listener)
def remove_listener(self, ev, listener):
if not isinstance(ev, basestring):
raise ValueError, "ev must be a string"
ll = self.__listeners.get(ev)
if ll:
try:
ll.remove(listener)
except KeyError:
pass
def fire_event(self, ev, *args):
ll = self.__listeners.get(ev)
if ll:
for listener in ll:
try:
listener(*args)
except:
self.LOGGER.warn("error running listener %r " "with ev=%r, args=%r", listener, ev, args, exc_info=1)
def shutdown(self):
if self.zh:
self.zh.stop()
self.zh = None
class ZkCoordinator(StaticCoordinator):
@staticmethod
def fromGroup(zkConnect: str, group: str) -> 'ZkCoordinator':
"""Convenience method for instantiation using conventional paths based on group.
The path convention is:
/static_assignment/[group]/assignments
/static_assignment/[group]/members
Args:
zkConnect (str): Comma-separated list of hosts to connect to (e.g. 127.0.0.1:2181,127.0.0.1:2182,[::1]:2183).
group (str): The name of the consumer group this coordinator belongs to. Must not be None.
"""
if group is None or len(group.strip()) == 0:
raise ValueError('ZkCoordinator: Invalid `group` argument, it must not be None or blank.')
prePath = f'/static_assignment/{group.strip()}'
assignmentPath = f'{prePath}/assignment'
membersPath = f'{prePath}/members'
return ZkCoordinator(zkConnect, membersPath, assignmentPath)
def __init__(self, zkConnect: str, membersPath: str, assignmentsPath: str):
"""Zookeeper implementation of `StaticCoordinator`
Args:
zkConnect (str): Comma-separated list of hosts to connect to (e.g. 127.0.0.1:2181,127.0.0.1:2182,[::1]:2183).
membersPath (str): Zookeeper path at which members will create ephemeral nodes asserting their ID.
assignmentsPath (str): Zookeeper path at which the current assignments are kept.
"""
for val, name in ((zkConnect, 'zkConnect'), (membersPath, 'membersPath'), (assignmentsPath, 'assignmentsPath')):
if val is None or len(val.strip()) == 0:
raise ValueError(f'ZkCoordinator: Invalid `{name}` argument, it must not be None or blank')
logger.info('ZKCoordinator starting with, membersPath=%s, assignmentsPath=%s', membersPath, assignmentsPath)
self._zkConnect = zkConnect
self._membersPath = membersPath
self._membersPathEnsured = False
self._assignmentsPath = assignmentsPath
self._assignmentsPathEnsured = False
self._currentAssignment = None
self._assignmentsWatcher = None
self._memberMetaData: Optional[StaticMemberMeta] = None
self.zk = KazooClient(hosts=zkConnect)
self.zk.add_listener(self._zkListener())
self._memberId: Optional[MemberId] = None
def _zkListener(self):
def listener(state):
if state == KazooState.LOST:
self._memberId = None
self._currentAssignment = None
return listener
def _establishSession(self):
if self._assignmentsWatcher is None:
# add watch for assignment updates
def watchAssignments(data, stat, event):
self._currentAssignment = self._processAssignmentsData(data)
logger.info('Assignment update received. | assignments= %s', self._currentAssignment)
self._ensureAssignmentsPath()
self._assignmentWatcher = DataWatch(self.zk, self._assignmentsPath, watchAssignments)
def _ensureAssignmentsPath(self):
if not self._assignmentsPathEnsured:
self.zk.ensure_path(self._assignmentsPath)
self._assignmentsPathEnsured = True
def _fetchAssignments(self) -> Optional[Assignments]:
return self._currentAssignment
def _processAssignmentsData(self, rawData):
if rawData is not None:
return Assignments.fromJson(rawData.decode('utf-8'))
def _ensureMembersPath(self):
if not self._membersPathEnsured:
self.zk.ensure_path(self._membersPath)
self._membersPathEnsured = True
def _createPath(self, altMemberId: MemberId = None):
mid = self._memberId
if altMemberId is not None:
mid = altMemberId
if mid is not None:
return f'{self._membersPath}/{mid}'
return None
def _encodeMemberData(self, meta: StaticMemberMeta):
return ujson.dumps(meta.asDict()).encode('utf-8')
def _compareAndUpdateMemberData(self, meta: StaticMemberMeta):
newDict = None
selfDict = None
if self._memberMetaData is not None and meta is not None:
selfDict = self._memberMetaData.asDict()
newDict = meta.asDict()
isDiff = (
selfDict['hostId'] != newDict['hostId']
or selfDict['assignment']['configVersion'] != newDict['assignment']['configVersion']
or selfDict['assignment']['version'] != newDict['assignment']['version']
)
else:
isDiff = True
if isDiff:
self._memberMetaData = meta
path = self._createPath()
if path is not None:
def cb(async_obj):
try:
async_obj.get()
logger.info('Member meta data updated. | metaData=%s', meta)
except (ConnectionLoss, SessionExpiredError):
logger.exception('Failed to update member meta data.')
self.zk.set_async(path, self._encodeMemberData(meta)).rawlink(cb)
def updateAssignments(self, meta: StaticMemberMeta, newAssignments: Assignments):
self.zk.retry(self._innerUpdateAssignment, newAssignments)
def _innerUpdateAssignment(self, assignment: Assignments):
self._ensureAssignmentsPath()
self.zk.set(self._assignmentsPath, assignment.asJson().encode('utf-8'))
logger.info('Assignments updated. | assignments=%s', assignment)
def leave(self, meta: StaticMemberMeta):
self.zk.retry(self._innerLeave)
def _innerLeave(self):
path = self._createPath()
if path is not None:
try:
self.zk.delete(path)
except (ConnectionLoss, SessionExpiredError):
logger.exception(
'Failed to relinquish member ID, '
"will assume ephemeral node will expire on it's own. "
'| memberId=%s',
self._memberId,
)
self._memberId = None
def join(self, meta: StaticMemberMeta):
asgns = self._fetchAssignments()
if asgns is None:
logger.warning('Cannot join a group without assignments. | assignmentsPath=%s', self._assignmentsPath)
return None
if self._memberId is None:
self._memberId = self._inner_join(meta, asgns.maxMembers)
return self._memberId
def _inner_join(self, meta: StaticMemberMeta, maxMembers: int) -> Optional[MemberId]:
idList = range(maxMembers)
memberData = self._encodeMemberData(meta)
self._ensureMembersPath()
foundMid = None
for mid in idList:
memberIdPath = self._createPath(mid)
try:
self.zk.create(memberIdPath, memberData, ephemeral=True)
foundMid = mid
logging.debug('Member id acquired. | memberId=%s', mid)
break
except NodeExistsError:
# move onto the next node
logger.debug('Member id already taken moving to next. | memberId=%s', mid)
except (ConnectionLoss, SessionExpiredError):
logger.exception('Member id acquisition attempt failed with error.')
time.sleep(1)
self._memberMetaData = meta
return foundMid
def assignments(self, meta: StaticMemberMeta) -> Optional[Assignments]:
self._compareAndUpdateMemberData(meta)
return self._fetchAssignments()
def heartbeat(self, meta: StaticMemberMeta) -> Optional[MemberId]:
self._compareAndUpdateMemberData(meta)
return self._memberId
def stop(self):
self.zk.stop()
self.zk.close()
def start(self):
self.zk.start()
self._establishSession()
