x/vmware-nsx
Code Issues Proposed changes

Add LeastRouters Scheduler to Neutron L3 Agent

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Allow scheduling of a virtual router on an L3 Agent node with the least
number of routers currently scheduled. This scheduler can be used
instead of the default random scheduler.

Also refactor the l3_agent_scheduler to allow for adding new schedulers.

Implement blueprint lessrouter-scheduler
Change-Id: Ie539c08bdc8a6e1430a106f77d08f15abd0903e7
This commit is contained in:
Sylvain Afchain 2013-11-26 22:24:33 +01:00
parent e7b13fe3e9
commit 91a7697b1e
3 changed files with 281 additions and 22 deletions
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12
neutron/db/l3_agentschedulers_db.py
View File

@ -17,6 +17,7 @@
from oslo.config import cfg
import sqlalchemy as sa
from sqlalchemy import func
from sqlalchemy import orm
from sqlalchemy.orm import exc
from sqlalchemy.orm import joinedload
@ -249,3 +250,14 @@ class L3AgentSchedulerDbMixin(l3agentscheduler.L3AgentSchedulerPluginBase,
"""Schedule the routers to l3 agents."""
for router in routers:
self.schedule_router(context, router)
def get_l3_agent_with_min_routers(self, context, agent_ids):
"""Return l3 agent with the least number of routers."""
query = context.session.query(
agents_db.Agent,
func.count(
RouterL3AgentBinding.router_id
).label('count')).outerjoin(RouterL3AgentBinding).group_by(
RouterL3AgentBinding.l3_agent_id).order_by('count')
res = query.filter(agents_db.Agent.id.in_(agent_ids)).first()
return res[0]

81
neutron/scheduler/l3_agent_scheduler.py
View File

@ -15,8 +15,10 @@
# License for the specific language governing permissions and limitations
# under the License.
import abc
import random
import six
from sqlalchemy.orm import exc
from sqlalchemy.sql import exists
@ -30,14 +32,20 @@ from neutron.openstack.common import log as logging
LOG = logging.getLogger(__name__)
class ChanceScheduler(object):
"""Allocate a L3 agent for a router in a random way.
More sophisticated scheduler (similar to filter scheduler in nova?)
can be introduced later.
"""
@six.add_metaclass(abc.ABCMeta)
class L3Scheduler(object):
@abc.abstractmethod
def schedule(self, plugin, context, router_id):
"""Schedule the router to an active L3 agent.
Schedule the router only if it is not already scheduled.
"""
pass
def auto_schedule_routers(self, plugin, context, host, router_ids):
"""Schedule non-hosted routers to L3 Agent running on host.
If router_ids is given, each router in router_ids is scheduled
if it is not scheduled yet. Otherwise all unscheduled routers
are scheduled.
@ -104,34 +112,26 @@ class ChanceScheduler(object):
' on host %s'), host)
return False
# binding
for router_id in router_ids:
binding = l3_agentschedulers_db.RouterL3AgentBinding()
binding.l3_agent = l3_agent
binding.router_id = router_id
binding.default = True
context.session.add(binding)
self.bind_router(context, router_id, l3_agent)
return True
def schedule(self, plugin, context, router_id):
"""Schedule the router to an active L3 agent if there
is no enable L3 agent hosting it.
"""
def get_candidates(self, plugin, context, sync_router):
"""Return L3 agents where a router could be scheduled."""
with context.session.begin(subtransactions=True):
# allow one router is hosted by just
# one enabled l3 agent hosting since active is just a
# timing problem. Non-active l3 agent can return to
# active any time
l3_agents = plugin.get_l3_agents_hosting_routers(
context, [router_id], admin_state_up=True)
context, [sync_router['id']], admin_state_up=True)
if l3_agents:
LOG.debug(_('Router %(router_id)s has already been hosted'
' by L3 agent %(agent_id)s'),
{'router_id': router_id,
{'router_id': sync_router['id'],
'agent_id': l3_agents[0]['id']})
return
sync_router = plugin.get_router(context, router_id)
active_l3_agents = plugin.get_l3_agents(context, active=True)
if not active_l3_agents:
LOG.warn(_('No active L3 agents'))
@ -143,13 +143,50 @@ class ChanceScheduler(object):
sync_router['id'])
return
chosen_agent = random.choice(candidates)
return candidates
def bind_router(self, context, router_id, chosen_agent):
"""Bind the router to the l3 agent which has been chosen."""
with context.session.begin(subtransactions=True):
binding = l3_agentschedulers_db.RouterL3AgentBinding()
binding.l3_agent = chosen_agent
binding.router_id = sync_router['id']
binding.router_id = router_id
context.session.add(binding)
LOG.debug(_('Router %(router_id)s is scheduled to '
'L3 agent %(agent_id)s'),
{'router_id': sync_router['id'],
'agent_id': chosen_agent['id']})
{'router_id': router_id,
'agent_id': chosen_agent.id})
class ChanceScheduler(L3Scheduler):
"""Randomly allocate an L3 agent for a router."""
def schedule(self, plugin, context, router_id):
with context.session.begin(subtransactions=True):
sync_router = plugin.get_router(context, router_id)
candidates = self.get_candidates(plugin, context, sync_router)
if not candidates:
return
chosen_agent = random.choice(candidates)
self.bind_router(context, router_id, chosen_agent)
return chosen_agent
class LeastRoutersScheduler(L3Scheduler):
"""Allocate to an L3 agent with the least number of routers bound."""
def schedule(self, plugin, context, router_id):
with context.session.begin(subtransactions=True):
sync_router = plugin.get_router(context, router_id)
candidates = self.get_candidates(plugin, context, sync_router)
if not candidates:
return
candidate_ids = [candidate['id'] for candidate in candidates]
chosen_agent = plugin.get_l3_agent_with_min_routers(
context, candidate_ids)
self.bind_router(context, router_id, chosen_agent)
return chosen_agent

210
neutron/tests/unit/test_l3_schedulers.py Normal file
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@ -0,0 +1,210 @@
# Copyright (c) 2013 OpenStack Foundation
# 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.
#
# @author: Sylvain Afchain, eNovance SAS
# @author: Emilien Macchi, eNovance SAS
import contextlib
import uuid
import mock
from oslo.config import cfg
from neutron.api.v2 import attributes as attr
from neutron.common import constants
from neutron.common.test_lib import test_config
from neutron.common import topics
from neutron import context as q_context
from neutron.db import agents_db
from neutron.db import l3_agentschedulers_db
from neutron.extensions import l3 as ext_l3
from neutron import manager
from neutron.openstack.common import timeutils
from neutron.tests.unit import test_db_plugin
from neutron.tests.unit import test_l3_plugin
HOST = 'my_l3_host'
FIRST_L3_AGENT = {
'binary': 'neutron-l3-agent',
'host': HOST,
'topic': topics.L3_AGENT,
'configurations': {},
'agent_type': constants.AGENT_TYPE_L3,
'start_flag': True
}
HOST_2 = 'my_l3_host_2'
SECOND_L3_AGENT = {
'binary': 'neutron-l3-agent',
'host': HOST_2,
'topic': topics.L3_AGENT,
'configurations': {},
'agent_type': constants.AGENT_TYPE_L3,
'start_flag': True
}
DB_PLUGIN_KLASS = ('neutron.plugins.openvswitch.ovs_neutron_plugin.'
'OVSNeutronPluginV2')
class L3SchedulerTestExtensionManager(object):
def get_resources(self):
attr.RESOURCE_ATTRIBUTE_MAP.update(ext_l3.RESOURCE_ATTRIBUTE_MAP)
l3_res = ext_l3.L3.get_resources()
return l3_res
def get_actions(self):
return []
def get_request_extensions(self):
return []
class L3SchedulerTestCase(l3_agentschedulers_db.L3AgentSchedulerDbMixin,
test_db_plugin.NeutronDbPluginV2TestCase,
test_l3_plugin.L3NatTestCaseMixin):
def setUp(self):
test_config['plugin_name_v2'] = DB_PLUGIN_KLASS
ext_mgr = L3SchedulerTestExtensionManager()
test_config['extension_manager'] = ext_mgr
super(L3SchedulerTestCase, self).setUp()
self.adminContext = q_context.get_admin_context()
self.plugin = manager.NeutronManager.get_plugin()
self._register_l3_agents()
def _register_l3_agents(self):
callback = agents_db.AgentExtRpcCallback()
callback.report_state(self.adminContext,
agent_state={'agent_state': FIRST_L3_AGENT},
time=timeutils.strtime())
agent_db = self.plugin.get_agents_db(self.adminContext,
filters={'host': [HOST]})
self.agent_id1 = agent_db[0].id
callback.report_state(self.adminContext,
agent_state={'agent_state': SECOND_L3_AGENT},
time=timeutils.strtime())
agent_db = self.plugin.get_agents_db(self.adminContext,
filters={'host': [HOST]})
self.agent_id2 = agent_db[0].id
def _set_l3_agent_admin_state(self, context, agent_id, state=True):
update = {'agent': {'admin_state_up': state}}
self.plugin.update_agent(context, agent_id, update)
@contextlib.contextmanager
def router_with_ext_gw(self, name='router1', admin_state_up=True,
fmt=None, tenant_id=str(uuid.uuid4()),
external_gateway_info=None,
subnet=None, set_context=False,
**kwargs):
router = self._make_router(fmt or self.fmt, tenant_id, name,
admin_state_up, external_gateway_info,
set_context, **kwargs)
self._add_external_gateway_to_router(
router['router']['id'],
subnet['subnet']['network_id'])
try:
yield router
finally:
self._remove_external_gateway_from_router(
router['router']['id'], subnet['subnet']['network_id'])
self._delete('routers', router['router']['id'])
class L3AgentChanceSchedulerTestCase(L3SchedulerTestCase):
def test_random_scheduling(self):
random_patch = mock.patch('random.choice')
random_mock = random_patch.start()
def side_effect(seq):
return seq[0]
random_mock.side_effect = side_effect
with self.subnet() as subnet:
self._set_net_external(subnet['subnet']['network_id'])
with self.router_with_ext_gw(name='r1', subnet=subnet) as r1:
agents = self.get_l3_agents_hosting_routers(
self.adminContext, [r1['router']['id']],
admin_state_up=True)
self.assertEqual(len(agents), 1)
self.assertEqual(random_mock.call_count, 1)
with self.router_with_ext_gw(name='r2', subnet=subnet) as r2:
agents = self.get_l3_agents_hosting_routers(
self.adminContext, [r2['router']['id']],
admin_state_up=True)
self.assertEqual(len(agents), 1)
self.assertEqual(random_mock.call_count, 2)
random_patch.stop()
class L3AgentLeastRoutersSchedulerTestCase(L3SchedulerTestCase):
def setUp(self):
cfg.CONF.set_override('router_scheduler_driver',
'neutron.scheduler.l3_agent_scheduler.'
'LeastRoutersScheduler')
super(L3AgentLeastRoutersSchedulerTestCase, self).setUp()
def test_scheduler(self):
# disable one agent to force the scheduling to the only one.
self._set_l3_agent_admin_state(self.adminContext,
self.agent_id2, False)
with self.subnet() as subnet:
self._set_net_external(subnet['subnet']['network_id'])
with self.router_with_ext_gw(name='r1', subnet=subnet) as r1:
agents = self.get_l3_agents_hosting_routers(
self.adminContext, [r1['router']['id']],
admin_state_up=True)
self.assertEqual(len(agents), 1)
agent_id1 = agents[0]['id']
with self.router_with_ext_gw(name='r2', subnet=subnet) as r2:
agents = self.get_l3_agents_hosting_routers(
self.adminContext, [r2['router']['id']],
admin_state_up=True)
self.assertEqual(len(agents), 1)
agent_id2 = agents[0]['id']
self.assertEqual(agent_id1, agent_id2)
# re-enable the second agent to see whether the next router
# spawned will be on this one.
self._set_l3_agent_admin_state(self.adminContext,
self.agent_id2, True)
with self.router_with_ext_gw(name='r3',
subnet=subnet) as r3:
agents = self.get_l3_agents_hosting_routers(
self.adminContext, [r3['router']['id']],
admin_state_up=True)
self.assertEqual(len(agents), 1)
agent_id3 = agents[0]['id']
self.assertNotEqual(agent_id1, agent_id3)