249 lines
11 KiB
Python
249 lines
11 KiB
Python
# 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 abc
|
|
import random
|
|
|
|
from oslo.db import exception as db_exc
|
|
import six
|
|
from sqlalchemy.orm import exc
|
|
from sqlalchemy import sql
|
|
|
|
from neutron.common import constants
|
|
from neutron.db import agents_db
|
|
from neutron.db import l3_agentschedulers_db
|
|
from neutron.db import l3_db
|
|
from neutron.openstack.common import log as logging
|
|
|
|
|
|
LOG = logging.getLogger(__name__)
|
|
|
|
|
|
@six.add_metaclass(abc.ABCMeta)
|
|
class L3Scheduler(object):
|
|
|
|
@abc.abstractmethod
|
|
def schedule(self, plugin, context, router_id,
|
|
candidates=None, hints=None):
|
|
"""Schedule the router to an active L3 agent.
|
|
|
|
Schedule the router only if it is not already scheduled.
|
|
"""
|
|
pass
|
|
|
|
def dvr_has_binding(self, context, router_id, l3_agent_id):
|
|
router_binding_model = l3_agentschedulers_db.RouterL3AgentBinding
|
|
|
|
query = context.session.query(router_binding_model)
|
|
query = query.filter(router_binding_model.router_id == router_id,
|
|
router_binding_model.l3_agent_id == l3_agent_id)
|
|
|
|
return query.count() > 0
|
|
|
|
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.
|
|
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 == sql.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 each of the specified routers is hosted
|
|
if router_ids:
|
|
routers = plugin.get_routers(
|
|
context, filters={'id': router_ids})
|
|
unscheduled_routers = []
|
|
for router in routers:
|
|
l3_agents = plugin.get_l3_agents_hosting_routers(
|
|
context, [router['id']], admin_state_up=True)
|
|
if l3_agents and not router.get('distributed', False):
|
|
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']})
|
|
else:
|
|
unscheduled_routers.append(router)
|
|
if not unscheduled_routers:
|
|
# all (specified) routers are already scheduled
|
|
return False
|
|
else:
|
|
# get all routers that are not hosted
|
|
#TODO(gongysh) consider the disabled agent's router
|
|
stmt = ~sql.exists().where(
|
|
l3_db.Router.id ==
|
|
l3_agentschedulers_db.RouterL3AgentBinding.router_id)
|
|
unscheduled_router_ids = [router_id_[0] for router_id_ in
|
|
context.session.query(
|
|
l3_db.Router.id).filter(stmt)]
|
|
if not unscheduled_router_ids:
|
|
LOG.debug(_('No non-hosted routers'))
|
|
return False
|
|
unscheduled_routers = plugin.get_routers(
|
|
context, filters={'id': unscheduled_router_ids})
|
|
|
|
# check if the configuration of l3 agent is compatible
|
|
# with the router
|
|
to_removed_ids = set()
|
|
for router in unscheduled_routers:
|
|
candidates = plugin.get_l3_agent_candidates(context,
|
|
router,
|
|
[l3_agent])
|
|
if not candidates:
|
|
to_removed_ids.add(router['id'])
|
|
|
|
target_routers = [r for r in unscheduled_routers
|
|
if r['id'] not in to_removed_ids]
|
|
if not target_routers:
|
|
LOG.warn(_('No routers compatible with L3 agent configuration'
|
|
' on host %s'), host)
|
|
return False
|
|
|
|
for router_dict in target_routers:
|
|
if (router_dict.get('distributed', False)
|
|
and self.dvr_has_binding(context,
|
|
router_dict['id'],
|
|
l3_agent.id)):
|
|
continue
|
|
self.bind_router(context, router_dict['id'], l3_agent)
|
|
return True
|
|
|
|
def get_candidates(self, plugin, context, sync_router, subnet_id):
|
|
"""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, [sync_router['id']], admin_state_up=True)
|
|
if l3_agents and not sync_router.get('distributed', False):
|
|
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
|
|
new_l3agents = plugin.get_l3_agent_candidates(context,
|
|
sync_router,
|
|
active_l3_agents,
|
|
subnet_id)
|
|
old_l3agentset = set(l3_agents)
|
|
if sync_router.get('distributed', False):
|
|
new_l3agentset = set(new_l3agents)
|
|
candidates = list(new_l3agentset - old_l3agentset)
|
|
else:
|
|
candidates = new_l3agents
|
|
if not candidates:
|
|
LOG.warn(_('No L3 agents can host the router %s'),
|
|
sync_router['id'])
|
|
return
|
|
|
|
return candidates
|
|
|
|
def bind_router(self, context, router_id, chosen_agent):
|
|
"""Bind the router to the l3 agent which has been chosen."""
|
|
try:
|
|
with context.session.begin(subtransactions=True):
|
|
binding = l3_agentschedulers_db.RouterL3AgentBinding()
|
|
binding.l3_agent = chosen_agent
|
|
binding.router_id = router_id
|
|
context.session.add(binding)
|
|
except db_exc.DBDuplicateEntry:
|
|
LOG.debug('Router %(router_id)s has already been scheduled '
|
|
'to L3 agent %(agent_id)s.',
|
|
{'agent_id': chosen_agent.id,
|
|
'router_id': router_id})
|
|
return
|
|
|
|
LOG.debug('Router %(router_id)s is scheduled to L3 agent '
|
|
'%(agent_id)s', {'router_id': router_id,
|
|
'agent_id': chosen_agent.id})
|
|
|
|
def _schedule_router(self, plugin, context, router_id,
|
|
candidates=None, hints=None):
|
|
sync_router = plugin.get_router(context, router_id)
|
|
subnet_id = hints.get('subnet_id') if hints else None
|
|
if (hints and 'gw_exists' in hints
|
|
and sync_router.get('distributed', False)):
|
|
plugin.schedule_snat_router(
|
|
context, router_id, sync_router, hints['gw_exists'])
|
|
candidates = candidates or self.get_candidates(
|
|
plugin, context, sync_router, subnet_id)
|
|
if not candidates:
|
|
return
|
|
if sync_router.get('distributed', False):
|
|
for chosen_agent in candidates:
|
|
self.bind_router(context, router_id, chosen_agent)
|
|
else:
|
|
chosen_agent = self._choose_router_agent(
|
|
plugin, context, candidates)
|
|
self.bind_router(context, router_id, chosen_agent)
|
|
return chosen_agent
|
|
|
|
@abc.abstractmethod
|
|
def _choose_router_agent(self, plugin, context, candidates):
|
|
"""Choose an agent from candidates based on a specific policy."""
|
|
pass
|
|
|
|
|
|
class ChanceScheduler(L3Scheduler):
|
|
"""Randomly allocate an L3 agent for a router."""
|
|
|
|
def schedule(self, plugin, context, router_id,
|
|
candidates=None, hints=None):
|
|
with context.session.begin(subtransactions=True):
|
|
return self._schedule_router(
|
|
plugin, context, router_id, candidates=candidates, hints=hints)
|
|
|
|
def _choose_router_agent(self, plugin, context, candidates):
|
|
return random.choice(candidates)
|
|
|
|
|
|
class LeastRoutersScheduler(L3Scheduler):
|
|
"""Allocate to an L3 agent with the least number of routers bound."""
|
|
|
|
def schedule(self, plugin, context, router_id,
|
|
candidates=None, hints=None):
|
|
with context.session.begin(subtransactions=True):
|
|
return self._schedule_router(
|
|
plugin, context, router_id, candidates=candidates, hints=hints)
|
|
|
|
def _choose_router_agent(self, plugin, context, candidates):
|
|
candidate_ids = [candidate['id'] for candidate in candidates]
|
|
chosen_agent = plugin.get_l3_agent_with_min_routers(
|
|
context, candidate_ids)
|
|
return chosen_agent
|