首先准备好环境，rabbit安装见：
centos7.9 安装rabbitmq_fyihdg的博客-CSDN博客
我是这个成功安装的基础上搭建的rabbitmq集群，
我安装的是普通集群，
192.168.1.61 rabbitmq1 （主）
192.168.1.62 rabbitmq2 (从)
两台服务器修改如下：
vi /etc/hosts
使用命令查询主机是否修改：
hostnamectl
如果发现hostname名字没修改成host文件中的名字，执行命令修改：
hostnamectl set-hostname rabbitmq12、复制cookie内容
首先切换到.erlang.cookie，所有的目录，默认是在：/var/lib/rabbimq
但有时候，命令ll -a 居然没有！！！然后怎么办？写了一个程序，连接到rabbitmq,发几条消息，消费几条消息，重启后，就生成了。
cd /var/lib/rabbitmq
把主服务器上的.erlang.cookie文件，复制到从服务器，相同的位置，可以把这个文件下载到本机，再上传到从服务器，或者使用命令复制，在主服务器上操作：
scp .erlang.cookie root@192.168.1.62:/var/lib/rabbitmq/.erlang.cookie
回车会提示输入root密码，输入回车就行
然后授权， .erlang.cookie 文件权限只能是600，777我试过，不行的
chmod 600 .erlang.cookie
要注意这里，刚刚复制过来的是root,用户，要修改过来
chown rabbitmq:rabbitmq /var/lib/rabbitmq/.erlang.cookie
主服务器执行如今命令：
rabbitmqctl stop_app rabbitmqctl reset rabbitmqctl start_app
如果报：You cannot reset a node when it is the only disc node in a cluster，执行：
rabbitmqctl force_reset
执行rabbitmqctl stop_app命令可能会报错：
[root@rabbitmq01 rabbitmq]# rabbitmqctl stop_app
Stopping rabbit application on node rabbit@rabbitmq01 ...
Error: unable to perform an operation on node 'rabbit@rabbitmq01'. 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@rabbitmq01
* If target node is configured to use long node names, don't forget to use --longnames with CLI tools
DIAGNOSTICS
===========
attempted to contact: [rabbit@rabbitmq01]
rabbit@rabbitmq01:
* connected to epmd (port 4369) on rabbitmq01
* epmd reports: node 'rabbit' not running at all
no other nodes on rabbitmq01
* suggestion: start the node
Current node details:
* node name: 'rabbitmqcli-1562-rabbit@rabbitmq01'
* effective user's home directory: /var/lib/rabbitmq
* Erlang cookie hash: KiLCK6kZzMo9nB0K7pdlng==
解决的办法是，输入命令：
systemctl start rabbitmq-server
就可以解决了
然后从服务器分别执行命令：
rabbitmqctl stop_app rabbitmqctl reset rabbitmqctl join_cluster rabbit@rabbitmq1 rabbitmqctl start_app
可能会报以下错误：
[root@rabbitmq02 rabbitmq]# rabbitmqctl join_cluster rabbit@rabbitmq01 Clustering node rabbit@rabbitmq02 with rabbit@rabbitmq01 Error: unable to perform an operation on node 'rabbit@rabbitmq01'. 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@rabbitmq01 * If target node is configured to use long node names, don't forget to use --longnames with CLI tools DIAGNOSTICS =========== attempted to contact: [rabbit@rabbitmq01] rabbit@rabbitmq01: * unable to connect to epmd (port 4369) on rabbitmq01: address (cannot connect to host/port) Current node details: * node name: 'rabbitmqcli-1958-rabbit@rabbitmq02' * effective user's home directory: /var/lib/rabbitmq * Erlang cookie hash: KiLCK6kZzMo9nB0K7pdlng== [root@rabbitmq02 rabbitmq]# systemctl start firewalld [root@rabbitmq02 rabbitmq]# systemctl stop firewalld
解决的办法是，先开启防火封墙，再关闭
systemctl start firewalld systemctl stop firewalld3、创建用户登录查看是否创建成功
两台服务器分别执行命令，其中root是我自己定义，可以随意修改
rabbitmqctl add_user root root rabbitmqctl set_user_tags root administrator rabbitmqctl set_permissions -p / root ".*" ".*" ".*"
这样的方式还不够完善，一台挂了，另一台就无法消费消息了，所以， 要设置镜像模式：
查看集群状态：
rabbitmqctl cluster_status
集群搭建成功了
