配置rabbitmq集群时，报错

unable to connect to epmd (port 4369) on vm-246: nxdomain (non-existing domain)

详细报错内容
[root@vm-247 ~]# rabbitmqctl join_cluster rabbit@vm-246

Clustering node rabbit@vm-247 with rabbit@vm-246
Error: unable to perform an operation on node 'rabbit@vm-246'. 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@vm-246
 * If target node is configured to use long node names, don't forget to use --longnames with CLI tools

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

attempted to contact: ['rabbit@vm-246']

rabbit@vm-246:
  * unable to connect to epmd (port 4369) on vm-246: nxdomain (non-existing domain)


Current node details:
 * node name: 'rabbitmqcli-11445-rabbit@vm-247'
 * effective user's home directory: /var/lib/rabbitmq
 * Erlang cookie hash: NhgpfPAyGCfXaw13WdYU9w==

解决方法：
/etc/hosts 中把各个主机节点的hostname 加上

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.200.246 vm-246
192.168.200.247 vm-247

一定不要加rabbit@ ，我之前配成 192.168.200.246 rabbit@vm-246 了 查了半天