neutron/quantum/scheduler/l3_agent_scheduler.py
Maru Newby a13295b9a8 Enable automatic validation of many HACKING rules.
* Add hacking to the tox build - a set of flake8 plugins that
   perform automatic validation of many HACKING.rst rules.
 * This patch configures hacking in the tox build and performs
   the mechanical cleanup required to allow the checks to pass.
 * See https://pypi.python.org/pypi/hacking

Change-Id: Ie9b3eb5627a9b6dd181f79225abae422e6cf3777
2013-04-11 19:48:28 +00:00

151 lines
6.3 KiB
Python

# vim: tabstop=4 shiftwidth=4 softtabstop=4
# 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.
import random
from sqlalchemy.orm import exc
from sqlalchemy.sql import exists
from quantum.common import constants
from quantum.db import agents_db
from quantum.db import agentschedulers_db
from quantum.db import l3_db
from quantum.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.
"""
def auto_schedule_routers(self, plugin, context, host, router_id):
"""Schedule non-hosted routers to L3 Agent running on host.
If router_id is given, only this router is scheduled
if it is not hosted yet.
Don't schedule the routers which are hosted already
by active l3 agents.
"""
with context.session.begin(subtransactions=True):
# query if we have valid l3 agent on the host
query = context.session.query(agents_db.Agent)
query = query.filter(agents_db.Agent.agent_type ==
constants.AGENT_TYPE_L3,
agents_db.Agent.host == host,
agents_db.Agent.admin_state_up == True)
try:
l3_agent = query.one()
except (exc.MultipleResultsFound, exc.NoResultFound):
LOG.debug(_('No enabled L3 agent on host %s'),
host)
return False
if agents_db.AgentDbMixin.is_agent_down(
l3_agent.heartbeat_timestamp):
LOG.warn(_('L3 agent %s is not active'), l3_agent.id)
# check if the specified router is hosted
if router_id:
l3_agents = plugin.get_l3_agents_hosting_routers(
context, [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,
'agent_id': l3_agents[0]['id']})
return False
# get the router ids
if router_id:
router_ids = [(router_id,)]
else:
# get all routers that are not hosted
#TODO(gongysh) consider the disabled agent's router
stmt = ~exists().where(
l3_db.Router.id ==
agentschedulers_db.RouterL3AgentBinding.router_id)
router_ids = context.session.query(
l3_db.Router.id).filter(stmt).all()
if not router_ids:
LOG.debug(_('No non-hosted routers'))
return False
# check if the configuration of l3 agent is compatible
# with the router
router_ids = [router_id_[0] for router_id_ in router_ids]
routers = plugin.get_routers(context, filters={'id': router_ids})
to_removed_ids = []
for router in routers:
candidates = plugin.get_l3_agent_candidates(router, [l3_agent])
if not candidates:
to_removed_ids.append(router['id'])
router_ids = list(set(router_ids) - set(to_removed_ids))
if not router_ids:
LOG.warn(_('No routers compatible with L3 agent configuration'
' on host %s'), host)
return False
# binding
for router_id in router_ids:
binding = agentschedulers_db.RouterL3AgentBinding()
binding.l3_agent = l3_agent
binding.router_id = router_id
binding.default = True
context.session.add(binding)
return True
def schedule(self, plugin, context, sync_router):
"""Schedule the router to an active L3 agent if there
is no enable L3 agent hosting it.
"""
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, [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': sync_router['id'],
'agent_id': l3_agents[0]['id']})
return
active_l3_agents = plugin.get_l3_agents(context, active=True)
if not active_l3_agents:
LOG.warn(_('No active L3 agents'))
return
candidates = plugin.get_l3_agent_candidates(sync_router,
active_l3_agents)
if not candidates:
LOG.warn(_('No L3 agents can host the router %s'),
sync_router['id'])
return
chosen_agent = random.choice(candidates)
binding = agentschedulers_db.RouterL3AgentBinding()
binding.l3_agent = chosen_agent
binding.router_id = sync_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']})
return chosen_agent