def cleanup(args):
    now = dt.utcnow()
    server = '{server}:{port}'.format(server=args.server, port=args.port)
    logging.info('Connecting to {}'.format(server))
    zk = KazooClient(hosts=server)
    zk.start()

    for path in args.zk_paths:
        zk_path = '{}/{}'.format(args.zk_root_path, path)
        nodes = zk.get_children(zk_path)
        logging.info("Found {} nodes under {}".format(len(nodes), zk_path))

        deleted = 0
        for node in nodes:
            node_path = '{}/{}'.format(zk_path, node)
            data, stat = zk.get(node_path)
            last_modified = dt.fromtimestamp(stat.mtime/1000.0)
            if ((now - last_modified).days > args.age) or (args.inclusive and (now - last_modified).days >= args.age):
                if not args.dry_run:
                    # Kazoo does not support recursive async deletes
                    if stat.children_count == 0:
                        res = zk.delete_async(node_path)
                    else:
                        zk.delete(node_path, recursive=True)
                deleted += 1

        logging.info("Deleted {} nodes".format(deleted))

    zk.stop()
Exemple #2
0
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
Exemple #3
0
class ZookeeperServiceRegistry(BaseServiceRegistry):
    def __init__(self, hosts=DEFAULT_HOSTS, chroot=DEFAULT_CHROOT):
        super(ZookeeperServiceRegistry, self).__init__()
        self.chroot = chroot
        self.client = KazooClient(
            hosts=hosts,
            handler=SequentialGeventHandler(),
        )
        self.client.add_listener(self.on_kazoo_state_change)
        self.start_count = 0

    @classmethod
    def from_config(cls, config, **kwargs):
        return cls(hosts=config.get('hosts', DEFAULT_HOSTS),
                   chroot=config.get('chroot', DEFAULT_CHROOT),
                   **kwargs)

    def on_start(self, timeout=10):
        self.start_count += 1
        if self.start_count > 1:
            return
        started = self.client.start_async()
        started.wait(timeout=timeout)
        if not self.client.connected:
            raise RuntimeError('could not connect to zookeeper')
        logger.debug('connected to zookeeper (version=%s)',
                     '.'.join(map(str, self.client.server_version())))

    def on_stop(self):
        self.start_count -= 1
        if self.start_count != 0:
            return
        self.client.stop()

    def on_kazoo_state_change(self, state):
        logger.info('kazoo connection state changed to %s', state)

    def on_service_type_watch(self, service, event):
        try:
            if event.type == EventType.CHILD:
                # FIXME: figure out proper retry strategy
                self.client.retry(self.lookup, service.container, service)
        except Exception:
            logger.exception('error in service type watcher')

    def on_service_watch(self, service, event):
        try:
            prefix, service_type, identity = event.path.rsplit('/', 2)
            if event.type == EventType.DELETED:
                service.remove(identity)
        except Exception:
            logger.exception('error in service watcher')

    def _get_service_znode(self, service, service_type, identity):
        path = self._get_zk_path(service_type, identity)
        result = self.client.get_async(path,
                                       watch=functools.partial(
                                           self.on_service_watch, service))
        value, znode = result.get()
        items = six.iteritems(json.loads(value.decode('utf-8')))
        return {str(k): str(v) for k, v in items}

    def discover(self, container):
        result = self.client.get_children_async(path='%s/services' %
                                                self.chroot, )
        return list(result.get())

    def lookup(self, container, service, watch=True, timeout=1):
        def child_watch(event):
            print(event)

        service_type = service.service_type
        result = self.client.get_children_async(
            path='%s/services/%s' % (self.chroot, service_type),
            watch=functools.partial(self.on_service_type_watch, service),
        )
        try:
            names = result.get(timeout=timeout)
        except NoNodeError:
            raise LookupFailure(None,
                                "failed to resolve %s" % service.service_type)
        logger.info("lookup %s %r", service_type, names)
        identities = set(service.identities())
        for name in names:
            kwargs = self._get_service_znode(service, service_type, name)
            identity = kwargs.pop('identity')
            service.update(identity, **kwargs)
            try:
                identities.remove(identity)
            except KeyError:
                pass
        for identity in identities:
            service.remove(identity)
        return service

    def _get_zk_path(self, service_type, identity):
        return '%s/services/%s/%s' % (self.chroot, service_type, identity)

    def register(self, container, service_type, timeout=1):
        path = self._get_zk_path(service_type, container.identity)
        value = json.dumps({
            'endpoint': container.endpoint,
            'identity': container.identity,
            'log_endpoint': container.log_endpoint,
        })
        result = self.client.create_async(path,
                                          value.encode('utf-8'),
                                          ephemeral=True,
                                          makepath=True)
        # FIXME: result.set_exception(RegistrationFailure())
        result.get(timeout=timeout)

    def unregister(self, container, service_type, timeout=1):
        path = self._get_zk_path(service_type, container.identity)
        result = self.client.delete_async(path)
        result.set_exception(RegistrationFailure())
        result.get(timeout=timeout)
Exemple #4
0
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
Exemple #5
0
class ZookeeperServiceRegistry(BaseServiceRegistry):
    def __init__(self, hosts=DEFAULT_HOSTS, chroot=DEFAULT_CHROOT):
        super(ZookeeperServiceRegistry, self).__init__()
        self.chroot = chroot
        self.client = KazooClient(
            hosts=hosts,
            handler=SequentialGeventHandler(),
        )
        self.client.add_listener(self.on_kazoo_state_change)
        self.start_count = 0

    @classmethod
    def from_config(cls, config, **kwargs):
        return cls(
            hosts=config.get('hosts', DEFAULT_HOSTS),
            chroot=config.get('chroot', DEFAULT_CHROOT),
            **kwargs
        )

    def on_start(self, timeout=10):
        self.start_count += 1
        if self.start_count > 1:
            return
        started = self.client.start_async()
        started.wait(timeout=timeout)
        if not self.client.connected:
            raise RuntimeError('could not connect to zookeeper')
        logger.debug('connected to zookeeper (version=%s)', '.'.join(map(str, self.client.server_version())))

    def on_stop(self):
        self.start_count -= 1
        if self.start_count != 0:
            return
        self.client.stop()

    def on_kazoo_state_change(self, state):
        logger.info('kazoo connection state changed to %s', state)

    def on_service_type_watch(self, service, event):
        try:
            if event.type == EventType.CHILD:
                # FIXME: figure out proper retry strategy
                self.client.retry(self.lookup, service.container, service)
        except Exception:
            logger.exception('error in service type watcher')

    def on_service_watch(self, service, event):
        try:
            prefix, service_type, identity = event.path.rsplit('/', 2)
            if event.type == EventType.DELETED:
                service.remove(identity)
        except Exception:
            logger.exception('error in service watcher')

    def _get_service_znode(self, service, service_type, identity):
        path = self._get_zk_path(service_type, identity)
        result = self.client.get_async(
            path, watch=functools.partial(self.on_service_watch, service))
        value, znode = result.get()
        items = six.iteritems(json.loads(value.decode('utf-8')))
        return {str(k): str(v) for k, v in items}

    def discover(self, container):
        result = self.client.get_children_async(
            path='%s/services' % self.chroot,
        )
        return list(result.get())

    def lookup(self, container, service, watch=True, timeout=1):
        def child_watch(event):
            print(event)
        service_type = service.service_type
        result = self.client.get_children_async(
            path='%s/services/%s' % (self.chroot, service_type),
            watch=functools.partial(self.on_service_type_watch, service),
        )
        try:
            names = result.get(timeout=timeout)
        except NoNodeError:
            raise LookupFailure(None, "failed to resolve %s" % service.service_type)
        logger.info("lookup %s %r", service_type, names)
        identities = set(service.identities())
        for name in names:
            kwargs = self._get_service_znode(service, service_type, name)
            identity = kwargs.pop('identity')
            service.update(identity, **kwargs)
            try:
                identities.remove(identity)
            except KeyError:
                pass
        for identity in identities:
            service.remove(identity)
        return service

    def _get_zk_path(self, service_type, identity):
        return '%s/services/%s/%s' % (self.chroot, service_type, identity)

    def register(self, container, service_type, timeout=1):
        path = self._get_zk_path(service_type, container.identity)
        value = json.dumps({
            'endpoint': container.endpoint,
            'identity': container.identity,
            'log_endpoint': container.log_endpoint,
        })
        result = self.client.create_async(
            path,
            value.encode('utf-8'),
            ephemeral=True, makepath=True)
        # FIXME: result.set_exception(RegistrationFailure())
        result.get(timeout=timeout)

    def unregister(self, container, service_type, timeout=1):
        path = self._get_zk_path(service_type, container.identity)
        result = self.client.delete_async(path)
        result.set_exception(RegistrationFailure())
        result.get(timeout=timeout)
Exemple #6
0
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()