首先，在节点rabbitmq01上执行命令：

sudo cat /var/lib/rabbitmq/.erlang.cookie

然后在节点rabbitmq02上

sudo service rabbitmq-server stop
sudo bash -c "echo rabbitmq01's cookie > /var/lib/rabbitmq/.erlang.cookie"
sudo service rabbitmq-server start
sudo rabbitmqctl stop_app
sudo rabbitmqctl reset  
sudo rabbitmqctl join_cluster rabbit@<rabbitmq01's hostname>
sudo rabbitmqctl start_app

如果join_cluster失败，请检查/var/lib/rabbitmq/.erlang.cookie访问权限是400还是600