openstack MQP server controller:5672 closed the connection. Check login crede...

重启后systemctl status openstack-nova-compute.service一直是pendding，systemctl start neutron-server.service也一直是pending。查看log记录，两个服务的报错信息都是如下：
2015-07-31 22:04:56.109 4865 INFO oslo.messaging._drivers.impl_rabbit [-] Connecting to AMQP server on controller:5672
2015-07-31 22:04:59.121 4865 ERROR oslo.messaging._drivers.impl_rabbit [-] AMQP server controller:5672 closed the connection. Check login credentials: Socket closed
2015-07-31 22:05:00.123 4865 INFO oslo.messaging._drivers.impl_rabbit [-] Delaying reconnect for 1.0 seconds...

查看rabbit的log发现：
=ERROR REPORT==== 31-Jul-2015::22:07:08 ===
closing AMQP connection <0.1050.0> (127.0.0.1:38222 -> 127.0.0.1:5672):
{handshake_error,starting,0,
                 {amqp_error,access_refused,
                             "AMQPLAIN login refused: user 'guest' - invalid credentials",
                             'connection.start_ok'}}
解决方法：
[root@controller ~]# rabbitmqctl list_users | grep guest
guest   [administrator]
[root@controller ~]# rabbitmqctl change_password guest RABBIT_PASS

重启rabbit服务，以及报错两个错误。问题解决

ERROR oslo.messaging._drivers.impl_rabbit [-] AMQP server controller:5672 closed the connection. Check login credentials: Socket closed，这个错误我也遇到过，但是排查之后是nova的配置文件写的有错误导致，修改之后启动正常，当时是所有nova的服务都起不来