解决rabbitmq报错：Error: unable to perform an operation on node ‘rabbit@rabbitmq02‘. Please see diagnosti

[root@rabbitmq02 rabbitmq]# rabbitmqctl stop_app
Stopping rabbit application on node rabbit@rabbitmq02 ...
Error: unable to perform an operation on node 'rabbit@rabbitmq02'. Please see diagnostics information and suggestions below.

Most common reasons for this are:

 * Target node is unreachable (e.g. due to hostname resolution, TCP connection or firewall issues)
 * CLI tool fails to authenticate with the server (e.g. due to CLI tool's Erlang cookie not matching that of the server)
 * Target node is not running

In addition to the diagnostics info below:

 * See the CLI, clustering and networking guides on https://rabbitmq.com/documentation.html to learn more
 * Consult server logs on node rabbit@rabbitmq02
 * If target node is configured to use long node names, don't forget to use --longnames with CLI tools

DIAGNOSTICS
===========

attempted to contact: [rabbit@rabbitmq02]

rabbit@rabbitmq02:
  * connected to epmd (port 4369) on rabbitmq02
  * epmd reports: node 'rabbit' not running at all
                  no other nodes on rabbitmq02
  * suggestion: start the node

Current node details:
 * node name: 'rabbitmqcli-1639-rabbit@rabbitmq02'
 * effective user's home directory: /var/lib/rabbitmq
 * Erlang cookie hash: KiLCK6kZzMo9nB0K7pdlng==

[root@rabbitmq02 rabbitmq]# systemctl start rabbitmq-server

解决很简单，执行：

systemctl start rabbitmq-server