RabbitMQ connection error messages are occasionally emitted

Issue

• RabbitMQ connection error messages are occasionally emitted into OpenStack components' logs.

  ERROR oslo.messaging._drivers.impl_rabbit [-] [aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa] AMQP server on controller-0.example.com:5672 is unreachable: Server unexpectedly closed connection. Trying again in 1 seconds.: OSError: Server unexpectedly closed connection
  ERROR oslo.messaging._drivers.impl_rabbit [-] [aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa] AMQP server on controller-0.example.com:5672 is unreachable: [Errno 104] Connection reset by peer. Trying again in 1 seconds.: ConnectionResetError: [Errno 104] Connection reset by peer
  

• RabbitMQ logs show some connection errors.

  [error] <0.0000.000> closing AMQP connection <0.6092.429> (10.0.0.1:XXXX -> 10.0.0.2:5672 - neutron-openvswitch-agent:1000:aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa
  {inet_error,etimedout}
  [info] <0.00000.000> Closing all channels from connection '10.0.0.1:XXXX -> 10.0.0.2:5672' because it has been closed