tooz/tooz/drivers/zake.py

66 lines
2.4 KiB
Python

# Copyright (c) 2013-2014 Mirantis Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import warnings
from zake import fake_client
from zake import fake_storage
from tooz import coordination
from tooz.drivers import zookeeper
class ZakeDriver(zookeeper.KazooDriver):
"""This driver uses the `zake`_ client to mimic real `zookeeper`_ servers.
It **should** be mainly used (and **is** really only intended to be used in
this manner) for testing and integration (where real `zookeeper`_ servers
are typically not available).
.. _zake: https://pypi.org/project/zake
.. _zookeeper: http://zookeeper.apache.org/
"""
CHARACTERISTICS = (
coordination.Characteristics.NON_TIMEOUT_BASED,
coordination.Characteristics.DISTRIBUTED_ACROSS_THREADS,
)
"""
Tuple of :py:class:`~tooz.coordination.Characteristics` introspectable
enum member(s) that can be used to interogate how this driver works.
"""
# NOTE(harlowja): this creates a shared backend 'storage' layer that
# would typically exist inside a zookeeper server, but since zake has
# no concept of a 'real' zookeeper server we create a fake one and share
# it among active clients to simulate zookeeper's consistent storage in
# a thread-safe manner.
fake_storage = fake_storage.FakeStorage(
fake_client.k_threading.SequentialThreadingHandler())
def __init__(self, member_id, parsed_url, options):
super(ZakeDriver, self).__init__(member_id, parsed_url, options)
warnings.warn(
"The zake driver is deprecated, and will be removed in "
"a future release."
)
@classmethod
def _make_client(cls, parsed_url, options):
if 'storage' in options:
storage = options['storage']
else:
storage = cls.fake_storage
return fake_client.FakeClient(storage=storage)