Comment 3 for bug 1652597

There was a lot of errors in neutron logs like this:

2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent Traceback (most recent call last):
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent File "/usr/lib/python2.7/dist-packages/neutron/agent/l3/agent.py", line 686, in _report_state
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent True)
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent File "/usr/lib/python2.7/dist-packages/neutron/agent/rpc.py", line 87, in report_state
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent return method(context, 'report_state', **kwargs)
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent File "/usr/lib/python2.7/dist-packages/oslo_messaging/rpc/client.py", line 158, in call
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent retry=self.retry)
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent File "/usr/lib/python2.7/dist-packages/oslo_messaging/transport.py", line 91, in _send
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent timeout=timeout, retry=retry)
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent File "/usr/lib/python2.7/dist-packages/oslo_messaging/_drivers/amqpdriver.py", line 512, in send
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent retry=retry)
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent File "/usr/lib/python2.7/dist-packages/oslo_messaging/_drivers/amqpdriver.py", line 503, in _send
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent raise result
2016-12-26 08:26:15.827 2080 ERROR neutron.agent.l3.agent RemoteError: Remote error: DBConnectionError (_mysql_exceptions.OperationalError) (2013, "Lost connection to MySQL server at 'reading initial communication packet', system error: 0") [SQL: u'SELECT 1']

For some reason MySQL server was restarted when "openstack-network-routers" task had been executing. Seems that caused the issue.

After that bug haven't been reproduced.