RabbitMQ概念及环境搭建（三）RabbitMQ cluster

太过爱你忘了你带给我的痛 2022-08-06 02:11 145阅读 0赞

测试环境：VMS00781 VMS00782 VMS00386 (centos5.8)  
1.先在三台机器上分别安装RabbitMQ Server  
  
2.读取其中一个节点的cookie，并复制到其他节点（节点间通过cookie确定相互是否可通信）  
两者之一均可：  
sudo vim /var/lib/rabbitmq/.erlang.cookie  
sudo vim $HOME/.erlang.cookie  
  
3.逐个启动节点  
sudo service rabbitmq-server start  
  
4.查看各节点中的RabbitMQ brokers  
sudo rabbitmqctl cluster\_status  
  
5.建集群  
分别在VMS00386、VMS00782 上执行  
sudo rabbitmqctl stop\_app  
sudo rabbitmqctl join\_cluster --ram rabbit@VMS00781  
sudo rabbitmqctl start\_app  
sudo rabbitmqctl stop\_app  
sudo rabbitmqctl join\_cluster rabbit@VMS00781  
sudo rabbitmqctl start\_app  
  
6.排错  
建集群过程中碰到如下错误：  
sudo rabbitmqctl join\_cluster --ram rabbit@VMS00386  
Clustering node rabbit@VMS00782 with rabbit@VMS00386 ...  
Error: unable to connect to nodes \[rabbit@VMS00386\]: nodedown  
DIAGNOSTICS  
===========  
attempted to contact: \[rabbit@VMS00386\]  
rabbit@VMS00386:  
  \* unable to connect to epmd (port 4369) on VMS00386: nxdomain (non-existing domain)  
current node details:  
\- node name: 'rabbitmqctl-8666@VMS00782'  
\- home dir: /var/lib/rabbitmq  
\- cookie hash: 50YO3zK+HJHos0tab1vHjg==  
解决之道：  
集群节点间需能互相访问，故每个集群节点的hosts文件应包含集群内所有节点的信息以保证互相解析  
vim /etc/hosts  
781's IP   VMS00781  
782's IP   VMS00782  
386's IP   vms00386  
之后重启各节点中的rabbitmq

7.其他问题

cluster搭建起来后若在web管理工具中rabbitmq\_management的Overview的Nodes部分看到“Node statistics not available”的信息，说明在该节点上web管理插件还未启用。

直接在显示提示信息的节点上运行sudo rabbitmq-plugins enable rabbitmq\_management即可。

Error: mnesia\_unexpectedly\_running  
原因：忘记先停止stop\_app  
解决：sudo rabbitmqctl stop\_app  
  
若rabbitmq-server第一次启动后hostname不能被解析或者发生了更改则会导致启动失败  
需执行如下操作  
sudo rm -rf /var/lib/rabbitmq/mnesia（因为相关信息会记录在此数据库）  
重装RabbitMQ Server  
  
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RabbitMQ cluster 管理  
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1.查看集群状态  
可分别在集群中各个节点执行  
sudo rabbitmqctl cluster\_status  
  
2.更改节点类型（内存型或磁盘型）  
sudo rabbitmqctl stop\_app  
sudo rabbitmqctl change\_cluster\_node\_type disc  
或  
sudo rabbitmqctl change\_cluster\_node\_type ram  
sudo rabbitmqctl start\_app  
  
3.重启cluster中的节点  
停止某个节点或者节点down掉剩余节点不受影响  
\[op1@vms00386 ~\]$ sudo rabbitmqctl stop  
Stopping and halting node rabbit@vms00386 ...  
  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@VMS00781 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781,rabbit@VMS00782,rabbit@vms00386\]\}\]\},  
 \{running\_nodes,\[rabbit@VMS00782,rabbit@VMS00781\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
  
\[op1@VMS00782 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@VMS00782 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781,rabbit@VMS00782,rabbit@vms00386\]\}\]\},  
 \{running\_nodes,\[rabbit@VMS00781,rabbit@VMS00782\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
  
\[op1@VMS00782 ~\]$ sudo rabbitmqctl stop  
Stopping and halting node rabbit@VMS00782 ...  
  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@VMS00781 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781,rabbit@VMS00782,rabbit@vms00386\]\}\]\},  
 \{running\_nodes,\[rabbit@VMS00781\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
  
待节点重启后自动追上其他节点  
\[op1@vms00386 ~\]$ sudo service rabbitmq-server start  
Starting rabbitmq-server: SUCCESS  
rabbitmq-server.  
  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@VMS00781 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781,rabbit@VMS00782,rabbit@vms00386\]\}\]\},  
 \{running\_nodes,\[rabbit@vms00386,rabbit@VMS00781\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
  
\[op1@VMS00782 ~\]$ sudo service rabbitmq-server start  
Starting rabbitmq-server: SUCCESS  
rabbitmq-server.  
  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@VMS00781 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781,rabbit@VMS00782,rabbit@vms00386\]\}\]\},  
 \{running\_nodes,\[rabbit@VMS00782,rabbit@vms00386,rabbit@VMS00781\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
  
\[op1@VMS00782 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@VMS00782 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781,rabbit@VMS00782,rabbit@vms00386\]\}\]\},  
 \{running\_nodes,\[rabbit@VMS00781,rabbit@vms00386,rabbit@VMS00782\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
  
\[op1@vms00386 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@vms00386 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781,rabbit@VMS00782,rabbit@vms00386\]\}\]\},  
 \{running\_nodes,\[rabbit@VMS00782,rabbit@VMS00781,rabbit@vms00386\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
  
几点注意：  
保证集群中至少有一个磁盘类型的节点以防数据丢失，在更改节点类型时尤其要注意。  
若整个集群被停掉了，应保证最后一个down掉的节点被最先启动，若不能则要使用forget\_cluster\_node命令将其移出集群  
若集群中节点几乎同时以不可控的方式down了此时在其中一个节点使用force\_boot命令重启节点  
  
4.从集群移除节点  
\[op1@vms00386 ~\]$ sudo rabbitmqctl stop\_app  
Stopping node rabbit@vms00386 ...  
\[op1@vms00386 ~\]$ sudo rabbitmqctl reset  
Resetting node rabbit@vms00386 ...  
\[op1@vms00386 ~\]$ sudo rabbitmqctl start\_app  
Starting node rabbit@vms00386 ...  
  
\[op1@vms00386 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@vms00386 ...  
\[\{nodes,\[\{disc,\[rabbit@vms00386\]\}\]\},  
 \{running\_nodes,\[rabbit@vms00386\]\},  
 \{cluster\_name,<<"rabbit@vms00386">>\},  
 \{partitions,\[\]\}\]  
  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@VMS00781 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781,rabbit@VMS00782\]\}\]\},  
 \{running\_nodes,\[rabbit@VMS00782,rabbit@VMS00781\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
  
\[op1@VMS00782 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@VMS00782 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781,rabbit@VMS00782\]\}\]\},  
 \{running\_nodes,\[rabbit@VMS00781,rabbit@VMS00782\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
可见rabbit@vms00386成为了独立的节点，原集群只剩rabbit@VMS00781,rabbit@VMS00782了  
  
也可在某个节点移除集群中其他节点  
如继续在rabbit@VMS00781上移除rabbit@VMS00782  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl forget\_cluster\_node rabbit@VMS00782  
Removing node rabbit@VMS00782 from cluster ...  
  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl cluster\_status  
Cluster status of node rabbit@VMS00781 ...  
\[\{nodes,\[\{disc,\[rabbit@VMS00781\]\}\]\},  
 \{running\_nodes,\[rabbit@VMS00781\]\},  
 \{cluster\_name,<<"rabbit@VMS00781">>\},  
 \{partitions,\[\]\}\]  
  
可见集群只剩rabbit@VMS00781一个节点了

这里有个问题，在远程其他节点中被移除的节点会自认为仍属于集群

\[op1@VMS00782 ~\]$ sudo rabbitmqctl start\_app  
Starting node rabbit@VMS00782 ...  
BOOT FAILED  
===========  
Error description:  
   \{error,\{inconsistent\_cluster,"Node rabbit@VMS00782 thinks it's clustered with node rabbit@VMS00781, but rabbit@VMS00781 disagrees"\}\}  
Log files (may contain more information):  
   /var/log/rabbitmq/rabbit@VMS00782.log  
   /var/log/rabbitmq/rabbit@VMS00782-sasl.log  
Stack trace:  
   \[\{rabbit\_mnesia,check\_cluster\_consistency,0\},  
    \{rabbit,'-start/0-fun-0-',0\},  
    \{rabbit,start\_it,1\},  
    \{rpc,'-handle\_call\_call/6-fun-0-',5\}\]  
Error: \{rabbit,failure\_during\_boot,  
           \{error,  
               \{inconsistent\_cluster,  
                   "Node rabbit@VMS00782 thinks it's clustered with node rabbit@VMS00781, but rabbit@VMS00781 disagrees"\}\}\}  
需要重置一下  
\[op1@VMS00782 ~\]$ sudo rabbitmqctl reset  
Resetting node rabbit@VMS00782 ...  
\[op1@VMS00782 ~\]$ sudo rabbitmqctl start\_app  
Starting node rabbit@VMS00782 ...  
  
此时三个节点均已成为独立的节点  
其中rabbit@vms00386、rabbit@VMS00782均被重置为了新的RabbitMQ broker而rabbit@VMS00781还保留着原cluster的残留状态可通过如下步骤重置  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl stop\_app  
Stopping node rabbit@VMS00781 ...  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl reset  
Resetting node rabbit@VMS00781 ...  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl start\_app  
Starting node rabbit@VMS00781 ...  
  
5.自动配置cluster  
显然，这是通过配置文件而非命令行工具进行的  
首先重置各节点  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl stop\_app  
Stopping node rabbit@VMS00781 ...  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl reset  
Resetting node rabbit@VMS00781 ...  
...  
其次调整配置文件  
\[\{rabbit,  
  \[\{cluster\_nodes, \{\['rabbit@VMS00781', 'rabbit@VMS00782', 'rabbit@vms00386'\], disc\}\}\]\}\].  
...  
之后启动各节点  
\[op1@VMS00781 ~\]$ sudo service rabbitmq-server start  
Starting rabbitmq-server: SUCCESS  
rabbitmq-server.  
  
查看集群状态  
\[op1@VMS00781 ~\]$ sudo rabbitmqctl cluster\_status  
  
几点注意：  
无论通过命令行还是通过配置文件配置，请确保各节点上Erlang和RabbitMQ版本一致  
配置文件仅对新鲜节点有效，也即被reset或者第一次启动的节点。因此在重启节点后自动化集群过程并不会发生。也以为这通过rabbitmq进行的改变优先于自动化集群配置。  
  
在一台机器上部署集群，一般用户测试集群特性  
这里的关键是已不同的端口可节点名称启动多个rabbitmq-server实例，其余过程同多机器上部署集群类似  
  
其他注意事项：  
如防火墙策略等  
  
参考：  
http://www.rabbitmq.com/clustering.html