openstack/nova
Code Issues Proposed changes

Fix up join() and leave() methods of servicegroup

Browse Source 
The join() method was not documented properly, and the Zookeeper
driver's implementation of the join() method returned a FakeLoopingCall
object for no reason whatsoever (the other drivers just return None), so
it's not necessary.

The leave() method wasn't used anywhere at all, therefore this patch
removes it entirely.

Change-Id: Idbd95636dbebfb4f21a25d23625ee338c1ba863e
Closes-bug: #1414513
Closes-bug: #1414515
This commit is contained in:
Jay Pipes
2015-01-25 16:56:47 -08:00
committed by EdLeafe
parent 5a9d7abb98
commit 7c38763761
5 changed files with 56 additions and 98 deletions
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28
nova/servicegroup/api.py
View File

@@ -75,21 +75,14 @@ class API(object):
self._driver = importutils.import_object(driver_class,
*args, **kwargs)
def join(self, member_id, group_id, service=None):
"""Add a new member to the ServiceGroup
def join(self, member, group, service=None):
"""Add a new member to a service group.
@param member_id: the joined member ID
@param group_id: the group name, of the joined member
@param service: the parameter can be used for notifications about
disconnect mode and update some internals
:param member: the joined member ID/name
:param group: the group ID/name, of the joined member
:param service: a `nova.service.Service` object
"""
LOG.debug('Join new ServiceGroup member %(member_id)s to the '
'%(group_id)s group, service = %(service)s',
{'member_id': member_id,
'group_id': group_id,
'service': service})
return self._driver.join(member_id, group_id, service)
return self._driver.join(member, group, service)
def service_is_up(self, member):
"""Check if the given member is up."""
@@ -97,15 +90,6 @@ class API(object):
# so this doesn't slow down the scheduler
return self._driver.is_up(member)
def leave(self, member_id, group_id):
"""Explicitly remove the given member from the ServiceGroup
monitoring.
"""
LOG.debug('Explicitly remove the given member %(member_id)s from the'
'%(group_id)s group monitoring',
{'member_id': member_id, 'group_id': group_id})
return self._driver.leave(member_id, group_id)
def get_all(self, group_id):
"""Returns ALL members of the given group."""
LOG.debug('Returns ALL members of the [%s] '

13
nova/servicegroup/drivers/base.py
View File

@@ -17,18 +17,19 @@ import random
class Driver(object):
"""Base class for all ServiceGroup drivers."""
def join(self, member_id, group_id, service=None):
"""Join the given service with its group."""
def join(self, member, group, service=None):
"""Add a new member to a service group.
:param member: the joined member ID/name
:param group: the group ID/name, of the joined member
:param service: a `nova.service.Service` object
"""
raise NotImplementedError()
def is_up(self, member):
"""Check whether the given member is up."""
raise NotImplementedError()
def leave(self, member_id, group_id):
"""Remove the given member from the ServiceGroup monitoring."""
raise NotImplementedError()
def get_all(self, group_id):
"""Returns ALL members of the given group."""
raise NotImplementedError()

14
nova/servicegroup/drivers/db.py
View File

@@ -46,12 +46,16 @@ class DbDriver(base.Driver):
self.conductor_api = conductor.API(use_local=self.db_allowed)
self.service_down_time = CONF.service_down_time
def join(self, member_id, group_id, service=None):
"""Join the given service with its group."""
def join(self, member, group, service=None):
"""Add a new member to a service group.
LOG.debug('DB_Driver: join new ServiceGroup member %(member_id)s to '
'the %(group_id)s group, service = %(service)s',
{'member_id': member_id, 'group_id': group_id,
:param member: the joined member ID/name
:param group: the group ID/name, of the joined member
:param service: a `nova.service.Service` object
"""
LOG.debug('DB_Driver: join new ServiceGroup member %(member)s to '
'the %(group)s group, service = %(service)s',
{'member': member, 'group': group,
'service': service})
if service is None:
raise RuntimeError(_('service is a mandatory argument for DB based'

58
nova/servicegroup/drivers/zk.py
View File

@@ -23,7 +23,6 @@ from oslo_utils import importutils
from nova import exception
from nova.i18n import _LE, _LW
from nova.openstack.common import loopingcall
from nova.servicegroup.drivers import base
evzookeeper = importutils.try_import('evzookeeper')
@@ -107,43 +106,33 @@ class ZooKeeperDriver(base.Driver):
'of it in production right now may be risky.'))
return session
def join(self, member_id, group, service=None):
"""Join the given service with its group."""
# process id
def join(self, member, group, service=None):
"""Add a new member to a service group.
:param member: the joined member ID/name
:param group: the group ID/name, of the joined member
:param service: a `nova.service.Service` object
"""
process_id = str(os.getpid())
LOG.debug('ZooKeeperDriver: join new member %(id)s(%(pid)s) to the '
'%(gr)s group, service=%(sr)s',
{'id': member_id, 'pid': process_id,
{'id': member, 'pid': process_id,
'gr': group, 'sr': service})
member = self._memberships.get((group, member_id), None)
member = self._memberships.get((group, member), None)
if member is None:
# the first time to join. Generate a new object
path = "%s/%s/%s" % (CONF.zookeeper.sg_prefix, group, member_id)
path = "%s/%s/%s" % (CONF.zookeeper.sg_prefix, group, member)
try:
member = membership.Membership(self._session, path, process_id)
zk_member = membership.Membership(self._session, path,
process_id)
except RuntimeError:
LOG.exception(_LE("Unable to join. It is possible that either"
" another node exists with the same name, or"
" this node just restarted. We will try "
"again in a short while to make sure."))
eventlet.sleep(CONF.zookeeper.sg_retry_interval)
member = membership.Membership(self._session, path, member_id)
self._memberships[(group, member_id)] = member
return FakeLoopingCall(self, member_id, group)
def leave(self, member_id, group):
"""Remove the given member from the service group."""
LOG.debug('ZooKeeperDriver.leave: %(member)s from group %(group)s',
{'member': member_id, 'group': group})
try:
key = (group, member_id)
member = self._memberships[key]
member.leave()
del self._memberships[key]
except KeyError:
LOG.error(_LE('ZooKeeperDriver.leave: %(id)s has not joined '
'to the %(gr)s group'),
{'id': member_id, 'gr': group})
zk_member = membership.Membership(self._session, path, member)
self._memberships[(group, member)] = zk_member
def is_up(self, service_ref):
group_id = service_ref['topic']
@@ -209,22 +198,3 @@ class ZooKeeperDriver(base.Driver):
all_members = filter(have_processes, all_members)
return all_members
class FakeLoopingCall(loopingcall.LoopingCallBase):
"""The fake Looping Call implementation, created for backward
compatibility with a membership based on DB.
"""
def __init__(self, driver, host, group):
self._driver = driver
self._group = group
self._host = host
def stop(self):
self._driver.leave(self._host, self._group)
def start(self, interval, initial_delay=None):
pass
def wait(self):
pass

41
nova/tests/unit/servicegroup/test_zk_driver.py
View File

@@ -26,7 +26,7 @@ $ nosetests nova.tests.unit.servicegroup.test_zk_driver
"""
import os
import eventlet
import mock
from nova import servicegroup
from nova.servicegroup.drivers import zk
@@ -37,33 +37,23 @@ class ZKServiceGroupTestCase(test.NoDBTestCase):
def setUp(self):
super(ZKServiceGroupTestCase, self).setUp()
from nova.servicegroup.drivers import zk
self.flags(servicegroup_driver='zk')
self.flags(address='localhost:2181', group="zookeeper")
try:
zk.ZooKeeperDriver()
__import__('evzookeeper')
__import__('zookeeper')
except ImportError:
self.skipTest("Unable to test due to lack of ZooKeeper")
def test_join_leave(self):
# Need to do this here, as opposed to the setUp() method, otherwise
# the decorate will cause an import error...
@mock.patch('evzookeeper.ZKSession')
def _setup_sg_api(self, zk_sess_mock):
self.zk_sess = mock.MagicMock()
zk_sess_mock.return_value = self.zk_sess
self.flags(servicegroup_driver='zk')
self.flags(address='ignored', group="zookeeper")
self.servicegroup_api = servicegroup.API()
service_id = {'topic': 'unittest', 'host': 'serviceA'}
self.servicegroup_api.join(service_id['host'], service_id['topic'])
self.assertTrue(self.servicegroup_api.service_is_up(service_id))
self.servicegroup_api.leave(service_id['host'], service_id['topic'])
# make sure zookeeper is updated and watcher is triggered
eventlet.sleep(1)
self.assertFalse(self.servicegroup_api.service_is_up(service_id))
def test_stop(self):
self.servicegroup_api = servicegroup.API()
service_id = {'topic': 'unittest', 'host': 'serviceA'}
pulse = self.servicegroup_api.join(service_id['host'],
service_id['topic'], None)
self.assertTrue(self.servicegroup_api.service_is_up(service_id))
pulse.stop()
eventlet.sleep(1)
self.assertFalse(self.servicegroup_api.service_is_up(service_id))
def test_zookeeper_hierarchy_structure(self):
"""Test that hierarchy created by join method contains process id."""
@@ -100,3 +90,12 @@ class ZKServiceGroupTestCase(test.NoDBTestCase):
# check that internal private session attribute is ready
self.assertIsInstance(driver.__dict__['_ZooKeeperDriver__session'],
evzookeeper.ZKSession)
@mock.patch('evzookeeper.membership.Membership')
def test_join(self, mem_mock):
self._setup_sg_api()
mem_mock.return_value = mock.sentinel.zk_mem
self.servicegroup_api.join('fake-host', 'fake-topic')
mem_mock.assert_called_once_with(self.zk_sess,
'/fake-topic',
'fake-host')