da65fe6951
- adds simple chance scheduling on create pool operation - adds PoolsLoadbalancerAgentBinding db table - adds lbaas_agentscheduler extension to list pools hosted by a particular agent and to get an agent hosting a particular pool - adds agent notifiers mapping to AgentSchedulerDbMixin to make it easier for services to add their agent notifiers to the core plugin Implements blueprint lbaas-agent-scheduler Change-Id: Id98649fd5c7873dcd5be1a2b117b8bed25f06cc2
115 lines
4.4 KiB
Python
115 lines
4.4 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
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# Copyright (c) 2013 OpenStack Foundation.
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# All Rights Reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License"); you may
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# not use this file except in compliance with the License. You may obtain
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# a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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import random
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import sqlalchemy as sa
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from sqlalchemy import orm
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from sqlalchemy.orm import joinedload
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from neutron.common import constants
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from neutron.db import agents_db
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from neutron.db import agentschedulers_db
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from neutron.db import model_base
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from neutron.extensions import lbaas_agentscheduler
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from neutron.openstack.common import log as logging
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LOG = logging.getLogger(__name__)
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class PoolLoadbalancerAgentBinding(model_base.BASEV2):
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"""Represents binding between neutron loadbalancer pools and agents."""
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pool_id = sa.Column(sa.String(36),
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sa.ForeignKey("pools.id", ondelete='CASCADE'),
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primary_key=True)
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agent = orm.relation(agents_db.Agent)
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agent_id = sa.Column(sa.String(36), sa.ForeignKey("agents.id",
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ondelete='CASCADE'))
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class LbaasAgentSchedulerDbMixin(agentschedulers_db.AgentSchedulerDbMixin,
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lbaas_agentscheduler
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.LbaasAgentSchedulerPluginBase):
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def get_lbaas_agent_hosting_pool(self, context, pool_id, active=None):
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query = context.session.query(PoolLoadbalancerAgentBinding)
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query = query.options(joinedload('agent'))
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binding = query.get(pool_id)
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if (binding and self.is_eligible_agent(
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active, binding.agent)):
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return {'agent': self._make_agent_dict(binding.agent)}
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def get_lbaas_agents(self, context, active=None, filters=None):
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query = context.session.query(agents_db.Agent)
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query = query.filter_by(agent_type=constants.AGENT_TYPE_LOADBALANCER)
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if active is not None:
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query = query.filter_by(admin_state_up=active)
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if filters:
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for key, value in filters.iteritems():
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column = getattr(agents_db.Agent, key, None)
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if column:
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query = query.filter(column.in_(value))
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return [agent
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for agent in query
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if self.is_eligible_agent(active, agent)]
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def list_pools_on_lbaas_agent(self, context, id):
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query = context.session.query(PoolLoadbalancerAgentBinding.pool_id)
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query = query.filter_by(agent_id=id)
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pool_ids = [item[0] for item in query]
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if pool_ids:
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return {'pools': self.get_pools(context, filters={'id': pool_ids})}
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else:
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return {'pools': []}
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class ChanceScheduler(object):
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"""Allocate a loadbalancer agent for a vip in a random way."""
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def schedule(self, plugin, context, pool):
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"""Schedule the pool to an active loadbalancer agent if there
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is no enabled agent hosting it.
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"""
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with context.session.begin(subtransactions=True):
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lbaas_agent = plugin.get_lbaas_agent_hosting_pool(
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context, pool['id'])
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if lbaas_agent:
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LOG.debug(_('Pool %(pool_id)s has already been hosted'
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' by lbaas agent %(agent_id)s'),
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{'pool_id': pool['id'],
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'agent_id': lbaas_agent['id']})
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return
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candidates = plugin.get_lbaas_agents(context, active=True)
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if not candidates:
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LOG.warn(_('No active lbaas agents for pool %s') % pool['id'])
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return
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chosen_agent = random.choice(candidates)
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binding = PoolLoadbalancerAgentBinding()
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binding.agent = chosen_agent
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binding.pool_id = pool['id']
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context.session.add(binding)
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LOG.debug(_('Pool %(pool_id)s is scheduled to '
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'lbaas agent %(agent_id)s'),
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{'pool_id': pool['id'],
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'agent_id': chosen_agent['id']})
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return chosen_agent
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