neutron/neutron/db/agents_db.py
armando-migliaccio 291048aba2 Tune up report and downtime intervals for l2 agent
If the neutron server erroneously thinks than the l2 agent is down
it will fail to bind a port, which can lead to VM's spawn errors.
However, the issue is only transient because the agent effectively
is only 'late' in reporting back.

Best solution would be an alpha-count algorithm (so that we can detect
persistent failures more reliably), but for now let's be more tolerant
assuming that the agent is down by waiting at least twice the report
interval plus a tiny teeny bit.

Change-Id: I544135ce1f6b7eaefb34ac44af8f5844d92ddd95
Close-bug: #1244255
2013-11-14 08:16:44 -08:00

187 lines
7.4 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.
from eventlet import greenthread
from oslo.config import cfg
import sqlalchemy as sa
from sqlalchemy.orm import exc
from neutron.db import model_base
from neutron.db import models_v2
from neutron.extensions import agent as ext_agent
from neutron import manager
from neutron.openstack.common import jsonutils
from neutron.openstack.common import log as logging
from neutron.openstack.common import timeutils
LOG = logging.getLogger(__name__)
cfg.CONF.register_opt(
cfg.IntOpt('agent_down_time', default=9,
help=_("Seconds to regard the agent is down; should be at "
"least twice report_interval, to be sure the "
"agent is down for good.")))
class Agent(model_base.BASEV2, models_v2.HasId):
"""Represents agents running in neutron deployments."""
# L3 agent, DHCP agent, OVS agent, LinuxBridge
agent_type = sa.Column(sa.String(255), nullable=False)
binary = sa.Column(sa.String(255), nullable=False)
# TOPIC is a fanout exchange topic
topic = sa.Column(sa.String(255), nullable=False)
# TOPIC.host is a target topic
host = sa.Column(sa.String(255), nullable=False)
admin_state_up = sa.Column(sa.Boolean, default=True,
nullable=False)
# the time when first report came from agents
created_at = sa.Column(sa.DateTime, nullable=False)
# the time when first report came after agents start
started_at = sa.Column(sa.DateTime, nullable=False)
# updated when agents report
heartbeat_timestamp = sa.Column(sa.DateTime, nullable=False)
# description is note for admin user
description = sa.Column(sa.String(255))
# configurations: a json dict string, I think 4095 is enough
configurations = sa.Column(sa.String(4095), nullable=False)
class AgentDbMixin(ext_agent.AgentPluginBase):
"""Mixin class to add agent extension to db_plugin_base_v2."""
def _get_agent(self, context, id):
try:
agent = self._get_by_id(context, Agent, id)
except exc.NoResultFound:
raise ext_agent.AgentNotFound(id=id)
return agent
@classmethod
def is_agent_down(cls, heart_beat_time):
return timeutils.is_older_than(heart_beat_time,
cfg.CONF.agent_down_time)
def get_configuration_dict(self, agent_db):
try:
conf = jsonutils.loads(agent_db.configurations)
except Exception:
msg = _('Configuration for agent %(agent_type)s on host %(host)s'
' is invalid.')
LOG.warn(msg, {'agent_type': agent_db.agent_type,
'host': agent_db.host})
conf = {}
return conf
def _make_agent_dict(self, agent, fields=None):
attr = ext_agent.RESOURCE_ATTRIBUTE_MAP.get(
ext_agent.RESOURCE_NAME + 's')
res = dict((k, agent[k]) for k in attr
if k not in ['alive', 'configurations'])
res['alive'] = not AgentDbMixin.is_agent_down(
res['heartbeat_timestamp'])
res['configurations'] = self.get_configuration_dict(agent)
return self._fields(res, fields)
def delete_agent(self, context, id):
with context.session.begin(subtransactions=True):
agent = self._get_agent(context, id)
context.session.delete(agent)
def update_agent(self, context, id, agent):
agent_data = agent['agent']
with context.session.begin(subtransactions=True):
agent = self._get_agent(context, id)
agent.update(agent_data)
return self._make_agent_dict(agent)
def get_agents_db(self, context, filters=None):
query = self._get_collection_query(context, Agent, filters=filters)
return query.all()
def get_agents(self, context, filters=None, fields=None):
return self._get_collection(context, Agent,
self._make_agent_dict,
filters=filters, fields=fields)
def _get_agent_by_type_and_host(self, context, agent_type, host):
query = self._model_query(context, Agent)
try:
agent_db = query.filter(Agent.agent_type == agent_type,
Agent.host == host).one()
return agent_db
except exc.NoResultFound:
raise ext_agent.AgentNotFoundByTypeHost(agent_type=agent_type,
host=host)
except exc.MultipleResultsFound:
raise ext_agent.MultipleAgentFoundByTypeHost(agent_type=agent_type,
host=host)
def get_agent(self, context, id, fields=None):
agent = self._get_agent(context, id)
return self._make_agent_dict(agent, fields)
def create_or_update_agent(self, context, agent):
"""Create or update agent according to report."""
with context.session.begin(subtransactions=True):
res_keys = ['agent_type', 'binary', 'host', 'topic']
res = dict((k, agent[k]) for k in res_keys)
configurations_dict = agent.get('configurations', {})
res['configurations'] = jsonutils.dumps(configurations_dict)
current_time = timeutils.utcnow()
try:
agent_db = self._get_agent_by_type_and_host(
context, agent['agent_type'], agent['host'])
res['heartbeat_timestamp'] = current_time
if agent.get('start_flag'):
res['started_at'] = current_time
greenthread.sleep(0)
agent_db.update(res)
except ext_agent.AgentNotFoundByTypeHost:
greenthread.sleep(0)
res['created_at'] = current_time
res['started_at'] = current_time
res['heartbeat_timestamp'] = current_time
res['admin_state_up'] = True
agent_db = Agent(**res)
greenthread.sleep(0)
context.session.add(agent_db)
greenthread.sleep(0)
class AgentExtRpcCallback(object):
"""Processes the rpc report in plugin implementations."""
RPC_API_VERSION = '1.0'
START_TIME = timeutils.utcnow()
def __init__(self, plugin=None):
self.plugin = plugin
def report_state(self, context, **kwargs):
"""Report state from agent to server."""
time = kwargs['time']
time = timeutils.parse_strtime(time)
if self.START_TIME > time:
LOG.debug(_("Message with invalid timestamp received"))
return
agent_state = kwargs['agent_state']['agent_state']
if not self.plugin:
self.plugin = manager.NeutronManager.get_plugin()
self.plugin.create_or_update_agent(context, agent_state)