【rabbitmq】rabbitmq集群环境搭建

安装rabbitmq-server

总共有3台虚拟机，都安装有rabbitmq服务，安装过程可参考：
【rabbitmq】Centos7 下安装rabbitmq

建立用户和vhost

说明： 此步骤不是必须的，文章后面的用户和vhost可能与此步骤建立的不一致，此处仅仅是建立的示例。

rabbitmqctl add_vhost /my_vhost

rabbitmqctl add_user admin admin
rabbitmqctl set_user_tags admin administrator #管理员权限

# rabbitmqctl set_permissions [-p vhost] [user] [permission ⇒ (modify) (write) (read)]
rabbitmqctl set_permissions -p /my_vhost admin ".*"  ".*" ".*"

rabbitmqctl list_permissions -p /my_vhost

机器列表

机器	ip	/etc/hostname	/etc/hostname	说明
node1	192.168.35.135	rmq-node1	rmq-node1	做为首节点
node2	192.168.35.136	rmq-node2	rmq-node2	加入node1集群
node3	192.168.35.137	rmq-node3	rmq-node3	加入node1集群

注意：修改/etc/hostname为上述表格中的值

# node1执行
[root@rmq-node1 ~]# rabbitmqctl status
Status of node 'rabbit@rmq-node1'
...

# node2执行
[root@rmq-node2 ~]#  rabbitmqctl status
Status of node 'rabbit@rmq-node2'
...

# node3执行
[root@rmq-node3 ~]#  rabbitmqctl status
Status of node 'rabbit@rmq-node3'
...

---

搭建集群环境

保证magic cookie相同

rabbitmq使用erlang编写，erlang自然具备分布式特性，为了是各erlang节点可以互相通讯，须要保证 magic cookie相同；

将node1中的cookie复制到node2和node3

# node2和 node3上分别执行
scp root@192.168.35.135:/var/lib/rabbitmq/.erlang.cookie /var/lib/rabbitmq/.erlang.cookie

如今3个node上的.erlang.cookie都是相同的；

注意点：

1. 须要保证.erlang.cookie的默认权限为：400;
   
2. 全部用户和组为 rabbitmq

chmod 400 /var/lib/rabbitmq/.erlang.cookie
chown rabbitmq:rabbitmq /var/lib/rabbitmq/.erlang.cookie

修改hosts文件

# 3个节点都要修改 hosts文件
vi /etc/hosts 

# 添加
192.168.35.135 rmq-node1
192.168.35.136 rmq-node2
192.168.35.137 rmq-node3

在每一个节点上，都保证能ping通

ping rmq-node1
ping rmq-node2
ping rmq-node3

将node2节点和node3节点加入集群

node2和node3加入集群前，node1的状态

[root@rmq-node1 ~]# rabbitmqctl  cluster_status
Cluster status of node 'rabbit@rmq-node1'
[{nodes,[{disc,['rabbit@rmq-node1']}]},   //此时只有一个节点
 {running_nodes,['rabbit@rmq-node1']},
 {cluster_name,<<"rabbit@rmq-node1">>},
 {partitions,[]},
 {alarms,[{'rabbit@rmq-node1',[]}]}]

说明：上面的rabbit@rmq-node1就是后面node2和node3要加入的首节点信息

node2做为disk节点

未加入以前

[root@rmq-node2 ~]# rabbitmqctl cluster_status
Cluster status of node 'rabbit@rmq-node2'
[{nodes,[{disc,['rabbit@rmq-node2']}]},
 {running_nodes,['rabbit@rmq-node2']},
 {cluster_name,<<"rabbit@rmq-node2">>},
 {partitions,[]},
 {alarms,[{'rabbit@rmq-node2',[]}]}]

加入集群

# stop application and reset
rabbitmqctl stop_app 
rabbitmqctl reset 

#join in cluster (specify only hostname, not with FQDN) 
rabbitmqctl join_cluster rabbit@rmq-node1

# start application
rabbitmqctl start_app

# show status
rabbitmqctl cluster_status

查看状态：

[root@rmq-node1 ~]# rabbitmqctl  cluster_status
Cluster status of node 'rabbit@rmq-node1'
[{nodes,[{disc,['rabbit@rmq-node1','rabbit@rmq-node2']}]},
 {running_nodes,['rabbit@rmq-node2','rabbit@rmq-node1']},
 {cluster_name,<<"rabbit@rmq-node1">>},
 {partitions,[]},
 {alarms,[{'rabbit@rmq-node2',[]},{'rabbit@rmq-node1',[]}]}]


[root@rmq-node2 ~]#  rabbitmqctl  cluster_status
Cluster status of node 'rabbit@rmq-node2'
[{nodes,[{disc,['rabbit@rmq-node1','rabbit@rmq-node2']}]},
 {running_nodes,['rabbit@rmq-node1','rabbit@rmq-node2']},
 {cluster_name,<<"rabbit@rmq-node1">>},
 {partitions,[]},
 {alarms,[{'rabbit@rmq-node1',[]},{'rabbit@rmq-node2',[]}]}]

node3做为ram节点

未加入以前

[root@rmq-node3 ~]# rabbitmqctl cluster_status
Cluster status of node 'rabbit@rmq-node3'
[{nodes,[{disc,['rabbit@rmq-node3']}]},
 {running_nodes,['rabbit@rmq-node3']},
 {cluster_name,<<"rabbit@rmq-node3">>},
 {partitions,[]},
 {alarms,[{'rabbit@rmq-node3',[]}]}]

加入集群

# stop application and reset
rabbitmqctl stop_app 
rabbitmqctl reset 

#join in cluster (specify only hostname, not with FQDN) 
rabbitmqctl join_cluster rabbit@rmq-node1 --ram

# start application
rabbitmqctl start_app

# show status
rabbitmqctl cluster_status

加入集群后的状态

[root@rmq-node1 ~]# rabbitmqctl  cluster_status
Cluster status of node 'rabbit@rmq-node1'
[{nodes,[{disc,['rabbit@rmq-node1','rabbit@rmq-node2']},
         {ram,['rabbit@rmq-node3']}]},
 {running_nodes,['rabbit@rmq-node3','rabbit@rmq-node2','rabbit@rmq-node1']},
 {cluster_name,<<"rabbit@rmq-node1">>},
 {partitions,[]},
 {alarms,[{'rabbit@rmq-node3',[]},
          {'rabbit@rmq-node2',[]},
          {'rabbit@rmq-node1',[]}]}]

-------------------
[root@rmq-node2 ~]# rabbitmqctl cluster_status
Cluster status of node 'rabbit@rmq-node2'
[{nodes,[{disc,['rabbit@rmq-node1','rabbit@rmq-node2']},
         {ram,['rabbit@rmq-node3']}]},
 {running_nodes,['rabbit@rmq-node3','rabbit@rmq-node1','rabbit@rmq-node2']},
 {cluster_name,<<"rabbit@rmq-node1">>},
 {partitions,[]},
 {alarms,[{'rabbit@rmq-node3',[]},
          {'rabbit@rmq-node1',[]},
          {'rabbit@rmq-node2',[]}]}]

-----------------------------

[root@rmq-node3 ~]# rabbitmqctl cluster_status
Cluster status of node 'rabbit@rmq-node3'
[{nodes,[{disc,['rabbit@rmq-node2','rabbit@rmq-node1']},
         {ram,['rabbit@rmq-node3']}]},
 {running_nodes,['rabbit@rmq-node1','rabbit@rmq-node2','rabbit@rmq-node3']},
 {cluster_name,<<"rabbit@rmq-node1">>},
 {partitions,[]},
 {alarms,[{'rabbit@rmq-node1',[]},
          {'rabbit@rmq-node2',[]},
          {'rabbit@rmq-node3',[]}]}]

登陆界面查看集群状态

http://192.168.35.135:15672/#/

---

相关概念

epmd

erlang port monitor deamon： 负责集群中节点ip和port的监控；
集群间node的发现都是经过该后台程序来完成的；

Mnesia

这是erlang的分布式数据库，用于存储queue、exchange、binding等信息；

---

网络分区（network partitions）

可参考： https://www.cnblogs.com/ssslinppp/p/9470962.html

---

其余运维操做

日志文件

/var/log/rabbitmq/xxxx.log

将某个node从集群中删除

rabbitmqctl forget_cluster_node rabbit@node-1  //这个属于硬删除

将node1节点删除后，如果从新加入该集群，可能报错，如：

inconsistent_cluster,"Node 'rabbit@node-1' thinks it's clustered with node 'rabbit@node-3', but 'rabbit@node-3' disagrees"}}

缘由：
从node-1的启动报错来看，像是集群信息残留；
在node-2上操做将node-1移除集群，node-1的rabbitmq服务已经down掉了，因此数据库没法同步更新，记载的还是旧的集群信息(数据库记录里自身节点仍属于集群)
而node-2和node-3的数据库记录已经更新(数据库信息里面集群不包含node-1节点了)
解决方式
删除node-1的数据库记录

rm -rf /var/lib/rabbitmq/mnesia/*

---

出现的错误

1. 启动失败：rabbitmq-server.service: control process exited, code=exited status=75

journalctl -xe

# 错误信息以下
Aug 08 19:25:44 localhost.localdomain systemd[1]: rabbitmq-server.service: control process exited, code=exited status=75
Aug 08 19:25:44 localhost.localdomain systemd[1]: Failed to start RabbitMQ broker.
-- Subject: Unit rabbitmq-server.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit rabbitmq-server.service has failed.
-- 
-- The result is failed.
Aug 08 19:25:44 localhost.localdomain systemd[1]: Unit rabbitmq-server.service entered failed state.
Aug 08 19:25:44 localhost.localdomain systemd[1]: rabbitmq-server.service failed.
Aug 08 19:25:44 localhost.localdomain polkitd[902]: Unregistered Authentication Agent for unix-process:3504:33878 (system bus name :1.17, object path /org/freedesktop/PolicyKit1/Aut
[root@localhost mnesia]# journalctl -xe

解决方式：

chown rabbitmq:rabbitmq /var/lib/rabbitmq/.erlang.cookie
rm -rf /var/lib/rabbitmq/mnesia/*