openstack neutron使用中遇到的问题总结

这篇文章将会持续更新，分享使用neutron过程中遇到的那些问题。

问题一：

搭建了控制和计算节点2台虚拟机环境，每台机器上都启动了linux bridge agent,但是通过openstack network agent list命令只能看到计算节点的linux bridge agent.

分析:

有了前面neutron源码的分析积累，我们知道linux bridge agent会向neutron-server定时汇报状态，因此查看这部分源码分析:

neutron/plugins/ml2/plugin.py:

首先是查看ml2 plugin安装的report_state rpc的endpoints:

@log_helpers.log_method_call
def start_rpc_listeners(self):
“””Start the RPC loop to let the plugin communicate with agents.”””
self._setup_rpc()
self.topic = topics.PLUGIN
self.conn = n_rpc.create_connection()
self.conn.create_consumer(self.topic, self.endpoints, fanout=False)
self.conn.create_consumer(
topics.SERVER_RESOURCE_VERSIONS,

[resources_rpc.ResourcesPushToServerRpcCallback()]

,
fanout=True)

process state reports despite dedicated rpc workers

self.conn.create_consumer(topics.REPORTS,

[agents_db.AgentExtRpcCallback()]

,
fanout=False)
return self.conn.consume_in_threads()

可以看到是agents_db.AgentExtRpcCallback().可知会调用其’report_state’函数：
neutron/db/agents_db.py:

@db_api.retry_if_session_inactive()
def report_state(self, context, **kwargs):
“””Report state from agent to server.
Returns - agent’s status: AGENT_NEW, AGENT_REVIVED, AGENT_ALIVE
“””
time = kwargs[‘time’]
time = timeutils.parse_strtime(time)
agent_state = kwargs[‘agent_state’][‘agent_state’]
self._check_clock_sync_on_agent_start(agent_state, time)
if self.START_TIME > time:
time_agent = datetime.datetime.isoformat(time)
time_server = datetime.datetime.isoformat(self.START_TIME)
log_dict = {‘agent_time’: time_agent, ‘server_time’: time_server}
LOG.debug(“Stale message received with timestamp: %(agent_time)s. “
“Skipping processing because it’s older than the “
“server start timestamp: %(server_time)s”, log_dict)
return
if not self.plugin:
self.plugin = manager.NeutronManager.get_plugin()
agent_status, agent_state = self.plugin.create_or_update_agent(
context, agent_state)
self._update_local_agent_resource_versions(context, agent_state)
return agent_status
可以看到会调用ml2插件的’create_or_update_agent’函数,这个函数是ml2 plugin混入的’AgentDbMixin’中的函数:
neutron/db/agents_db.py:

@db_api.retry_if_session_inactive()
def create_or_update_agent(self, context, agent_state):
“””Registers new agent in the database or updates existing.
Returns tuple of agent status and state.
Status is from server point of view: alive, new or revived.
It could be used by agent to do some sync with the server if needed.
“””
status = n_const.AGENT_ALIVE
with context.session.begin(subtransactions=True):
res_keys = [‘agent_type’, ‘binary’, ‘host’, ‘topic’]
res = dict((k, agent_state[k]) for k in res_keys)
if ‘availability_zone’ in agent_state:
res[‘availability_zone’] = agent_state[‘availability_zone’]
configurations_dict = agent_state.get(‘configurations’, {})
res[‘configurations’] = jsonutils.dumps(configurations_dict)
resource_versions_dict = agent_state.get(‘resource_versions’)
if resource_versions_dict:
res[‘resource_versions’] = jsonutils.dumps(
resource_versions_dict)
res[‘load’] = self._get_agent_load(agent_state)
current_time = timeutils.utcnow()
try:
agent_db = self._get_agent_by_type_and_host(
context, agent_state[‘agent_type’], agent_state[‘host’])
if not agent_db.is_active:
status = n_const.AGENT_REVIVED
if ‘resource_versions’ not in agent_state:

updating agent_state with resource_versions taken

from db so that

_update_local_agent_resource_versions() will call

version_manager and bring it up to date

agent_state[‘resource_versions’] = self._get_dict(
agent_db, ‘resource_versions’, ignore_missing=True)
res[‘heartbeat_timestamp’] = current_time
if agent_state.get(‘start_flag’):
res[‘started_at’] = current_time
greenthread.sleep(0)
self._log_heartbeat(agent_state, agent_db, configurations_dict)
agent_db.update(res)
event_type = events.AFTER_UPDATE
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’] = cfg.CONF.enable_new_agents
agent_db = Agent(**res)
greenthread.sleep(0)
context.session.add(agent_db)
event_type = events.AFTER_CREATE
self._log_heartbeat(agent_state, agent_db, configurations_dict)
status = n_const.AGENT_NEW
greenthread.sleep(0)

registry.notify(resources.AGENT, event_type, self, context=context,
                host=agent_state['host'], plugin=self,
                agent=agent_state)
return status, agent_state

注意红色部分，会根据上报状态的agent的类型和主机名查询数据库，如果已经存在则什么也不做，如果没有存在则会抛出异常’ext_agent.AgentNotFoundByTypeHost’,然后进行数据库插入操作。这里可以知道neutron-server是用agent类型和主机名做为键值的。

问题原因:

这样问题原因就找到了，因为我的控制节点和计算节点主机名相同，因此只能插入一个agent的信息。修改控制节点主机名后，2个linuxbridge agent就都出来了。

作者：self-motivation
来源：CSDN
原文：https://blog.csdn.net/happyAnger6/article/details/55224561
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