在上一篇博客中咱們簡單的介紹了下rabbitmq簡介,安裝配置相關指令的說明以及rabbitmqctl的相關子命令的說明;回顧請參考http://www.javashuo.com/article/p-huxkyxpb-nt.html;今天我 們來聊一聊rabbitmq的集羣;之因此要用集羣是由於在一個分佈式應用環境中,rabbitmq的做用是鏈接各組件,一旦rabbitmq服務掛掉,可能影響整個線上業務,爲了不這樣的問題出現,咱們就必須想辦法對rabbitmq作高可用,可以讓集羣中的每一個rabbitmq節點把自身接收到的消息經過網絡同步到其餘節點,這樣一來使得每一個節點都有整個rabbitmq集羣的全部消息,即使其中一臺rabbitmq宕機不影響消息丟失的狀況;rabbitmq集羣它的主要做用就是各節點互相同步消息,從而實現了數據的冗餘;除了rabbitmq的數據冗餘,咱們還須要考慮,一旦後端有多臺rabbitmq咱們就須要經過對後端多臺rabbitmq-server作負載均衡,使得每一個節點可以分擔一部分流量,同時對客戶端訪問提供一個統一的訪問接口;客戶端就能夠基於負載均衡的地址來請求rabbitmq,經過負載均衡調度,把客戶端的請求分攤到後端多個rabbitmq上;若是某一臺rabbitmq宕機了,根據負載均衡的健康狀態監測,自動將請求不調度到宕機的rabbitmq-server上,從而也實現了對rabbitmq高可用;html
在實現rabbitmq集羣前咱們須要作如下準備前端
一、更改各節點的主機名同hosts文件解析的主機名相同,必須保證各節點主機名稱不同,而且能夠經過hosts文件解析出來;node
二、時間同步,時間同步對於一個集羣來說是最基本的要求;nginx
三、各節點的cookie信息必須保持一致;web
實驗環境說明算法
節點名 | 主機名 | ip地址 |
node01 | node01 | 192.168.0.41 |
node2 | node2 | 192.168.0.42 |
負載均衡 | node3 | 192.168.0.43 |
一、配置各節點的主機名稱後端
[root@node01 ~]# hostnamectl set-hostname node01 [root@node01 ~]# cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.0.41 node01 192.168.0.42 node2 192.168.0.43 node3 [root@node01 ~]# scp /etc/hosts node2:/etc/ hosts 100% 218 116.4KB/s 00:00 [root@node01 ~]# scp /etc/hosts node3:/etc/ hosts 100% 218 119.2KB/s 00:00 [root@node01 ~]#
提示:對於rabbitmq集羣來說就只有node01和node2,這兩個節點互相同步消息;而負載均衡是爲了作流量負載而設定的,本質上不屬於rabbitmq集羣;因此對於負載均衡的主機名是什麼均可以;瀏覽器
驗證:連接個節點驗證主機名是否正確,以及hosts文件bash
[root@node2 ~]# hostname node2 [root@node2 ~]# cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.0.41 node01 192.168.0.42 node2 192.168.0.43 node3 [root@node2 ~]#
在各節點安裝rabbitmq-servercookie
yum install rabbitmq-server -y
啓動各節點rabbitmq-server
提示:node01上啓動了rabbitmq-management插件,因此15672處於監聽;而node2沒有啓動rabbitmq-management插件,15672端口並無處於監聽狀體;對於一個rabbitmq集羣,25672這個端口就是專用於集羣個節點通訊;
如今基本環境已經準備好,如今咱們就能夠來配置集羣了,rabbitmq集羣的配置很是簡單,默認狀況啓動一個rabbitmq,它就是一個集羣,因此25672處於監聽狀態嘛,只不過集羣中就只有一個自身節點;
驗證:各節點集羣狀態信息,節點名是否同主機hostname名稱相同
提示:從上面的信息能夠看到兩個節點的集羣名稱都是同host主機名相同;
中止node2上的應用,把node2加入node01集羣
提示:這裏提示咱們沒法鏈接到rabbit@node01,出現以上錯誤的主要緣由有兩個,第一個是主機名稱解析不正確;第二是cookie不一致;
複製cookie信息
[root@node2 ~]# scp /var/lib/rabbitmq/.erlang.cookie node01:/var/lib/rabbitmq/ The authenticity of host 'node01 (192.168.0.41)' can't be established. ECDSA key fingerprint is SHA256:EG9nua4JJuUeofheXlgQeL9hX5H53JynOqf2vf53mII. ECDSA key fingerprint is MD5:57:83:e6:46:2c:4b:bb:33:13:56:17:f7:fd:76:71:cc. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'node01,192.168.0.41' (ECDSA) to the list of known hosts. .erlang.cookie 100% 20 10.6KB/s 00:00 [root@node2 ~]#
驗證:md5sum驗證各節點cookie是否一致
[root@node2 ~]# md5sum /var/lib/rabbitmq/.erlang.cookie 1d4f9e4d6c92cf0c749cc4ace68317f6 /var/lib/rabbitmq/.erlang.cookie [root@node2 ~]# ssh node01 Last login: Wed Aug 26 19:41:30 2020 from 192.168.0.232 [root@node01 ~]# md5sum /var/lib/rabbitmq/.erlang.cookie 1d4f9e4d6c92cf0c749cc4ace68317f6 /var/lib/rabbitmq/.erlang.cookie [root@node01 ~]#
提示:如今兩個節點的cookie信息一致了,再次把node2加入到node01上看看是否可以加入?
[root@node2 ~]# rabbitmqctl join_cluster rabbit@node01 Clustering node rabbit@node2 with rabbit@node01 ... Error: unable to connect to nodes [rabbit@node01]: nodedown DIAGNOSTICS =========== attempted to contact: [rabbit@node01] rabbit@node01: * connected to epmd (port 4369) on node01 * epmd reports node 'rabbit' running on port 25672 * TCP connection succeeded but Erlang distribution failed * suggestion: hostname mismatch? * suggestion: is the cookie set correctly? current node details: - node name: rabbitmqctl2523@node2 - home dir: /var/lib/rabbitmq - cookie hash: HU+eTWySzwx0nMSs5oMX9g== [root@node2 ~]#
提示:仍是提示咱們加不進去,這裏的緣由是咱們更新了node01的cookie信息,沒有重啓rabbitmq-server,因此它默認仍是之前的cookie;
重啓node01上的rabbitmq-server
[root@node01 ~]# systemctl restart rabbitmq-server.service [root@node01 ~]# ss -tnl State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 128 127.0.0.1:631 *:* LISTEN 0 128 *:15672 *:* LISTEN 0 100 127.0.0.1:25 *:* LISTEN 0 100 127.0.0.1:64667 *:* LISTEN 0 128 *:8000 *:* LISTEN 0 128 *:8001 *:* LISTEN 0 128 *:25672 *:* LISTEN 0 5 127.0.0.1:8010 *:* LISTEN 0 128 *:111 *:* LISTEN 0 128 *:80 *:* LISTEN 0 128 *:4369 *:* LISTEN 0 5 192.168.122.1:53 *:* LISTEN 0 128 *:22 *:* LISTEN 0 128 ::1:631 :::* LISTEN 0 100 ::1:25 :::* LISTEN 0 128 :::5672 :::* LISTEN 0 128 :::111 :::* LISTEN 0 128 :::80 :::* LISTEN 0 128 :::4369 :::* LISTEN 0 128 :::22 :::* [root@node01 ~]#
提示:若是是把node01的cookie複製給node2,咱們須要重啓node2,總之拿到新cookie節點都要重啓,保證在用cookie的信息一致就能夠了;
再次把node2加入到node01
[root@node2 ~]# rabbitmqctl join_cluster rabbit@node01 Clustering node rabbit@node2 with rabbit@node01 ... ...done. [root@node2 ~]#
提示:加入對應節點集羣沒有報錯就表示加入集羣成功;
驗證:查看各節點的集羣狀態信息
提示:在兩個節點上咱們均可以看到兩個節點;到此node2就加入到node01這個集羣中了;可是兩個節點的集羣狀態信息不同,緣由是node2上沒有啓動應用,啓動應用之後,它倆的狀態信息就會是同樣;
啓動node2上的應用
提示:此時兩個節點的狀態信息就同樣了;到此rabbitmq集羣就搭建好了;
驗證:在瀏覽器登陸node1的15672,看看web管理界面是否有節點信息?
提示:node2之因此沒有統計信息是由於node2上沒有啓動rabbitmq-management插件;啓用插件就能夠統計到數據;
rabbitmqctl集羣相關子命令
join_cluster <clusternode> [--ram]:加入指定節點集羣;
cluster_status:查看集羣狀態
change_cluster_node_type disc | ram:更改節點存儲類型,disc表示磁盤,ram表示內存;一個集羣中必須有一個節點爲disc類型;
[root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2]}]}, {running_nodes,[rabbit@node01,rabbit@node2]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node2 ~]# rabbitmqctl change_cluster_node_type ram Turning rabbit@node2 into a ram node ... Error: mnesia_unexpectedly_running [root@node2 ~]#
提示:這裏提示咱們mnesia_unexpectedly_running,因此咱們更改不了節點類型;解決辦法是中止node2上的應用,而後在更改類型,在啓動應用便可;
[root@node2 ~]# rabbitmqctl stop_app Stopping node rabbit@node2 ... ...done. [root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2]}]}] ...done. [root@node2 ~]# rabbitmqctl change_cluster_node_type ram Turning rabbit@node2 into a ram node ... ...done. [root@node2 ~]# rabbitmqctl start_app Starting node rabbit@node2 ... ...done. [root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01]},{ram,[rabbit@node2]}]}, {running_nodes,[rabbit@node01,rabbit@node2]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node2 ~]#
提示:能夠看到node2就變成了ram類型了;
[root@node01 ~]# rabbitmqctl change_cluster_node_type ram Turning rabbit@node01 into a ram node ... Error: mnesia_unexpectedly_running [root@node01 ~]# rabbitmqctl stop_app Stopping node rabbit@node01 ... ...done. [root@node01 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node01 ... [{nodes,[{disc,[rabbit@node01]},{ram,[rabbit@node2]}]}] ...done. [root@node01 ~]# rabbitmqctl change_cluster_node_type ram Turning rabbit@node01 into a ram node ... Error: {resetting_only_disc_node,"You cannot reset a node when it is the only disc node in a cluster. Please convert another node of the cluster to a disc node first."} [root@node01 ~]#
提示:這裏須要注意一個集羣中至少保持一個節點是disc類型;因此node2更改爲ram類型,node01就必須是disc類型;
forget_cluster_node [--offline]:離開集羣;
[root@node01 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node01 ... [{nodes,[{disc,[rabbit@node01]},{ram,[rabbit@node2]}]}, {running_nodes,[rabbit@node2,rabbit@node01]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node01 ~]# rabbitmqctl forget_cluster_node rabbit@node2 Removing node rabbit@node2 from cluster ... Error: {failed_to_remove_node,rabbit@node2, {active,"Mnesia is running",rabbit@node2}} [root@node01 ~]#
提示:咱們在node01上移除node2,提示咱們node2節點處於活躍狀態不能移除;這也告訴咱們這個子命令只能移除不在線的節點;
下線node2上的應用
[root@node2 ~]# rabbitmqctl stop_app Stopping node rabbit@node2 ... ...done. [root@node2 ~]#
再次移除node2
[root@node01 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node01 ... [{nodes,[{disc,[rabbit@node01]},{ram,[rabbit@node2]}]}, {running_nodes,[rabbit@node01]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node01 ~]# rabbitmqctl forget_cluster_node rabbit@node2 Removing node rabbit@node2 from cluster ... ...done. [root@node01 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node01 ... [{nodes,[{disc,[rabbit@node01]}]}, {running_nodes,[rabbit@node01]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node01 ~]#
update_cluster_nodes clusternode:更新集羣節點信息;
把node2加入node01這個集羣
[root@node2 ~]# rabbitmqctl stop_app Stopping node rabbit@node2 ... ...done. [root@node2 ~]# rabbitmqctl join_cluster rabbit@node01 Clustering node rabbit@node2 with rabbit@node01 ... ...done. [root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2]}]}] ...done. [root@node2 ~]# rabbitmqctl start_app Starting node rabbit@node2 ... ...done. [root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2]}]}, {running_nodes,[rabbit@node01,rabbit@node2]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node2 ~]#
停掉node2上的應用
[root@node2 ~]# rabbitmqctl stop_app Stopping node rabbit@node2 ... ...done. [root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2]}]}] ...done. [root@node2 ~]#
提示:若是此時有新節點加入集羣,若是在把node01上的應用停掉,node2再次啓動應用就會提示錯誤;以下
把node3加入node01
[root@node3 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node3 ... [{nodes,[{disc,[rabbit@node3]}]}, {running_nodes,[rabbit@node3]}, {cluster_name,<<"rabbit@node3">>}, {partitions,[]}] ...done. [root@node3 ~]# rabbitmqctl stop_app Stopping node rabbit@node3 ... ...done. [root@node3 ~]# rabbitmqctl join_cluster rabbit@node01 Clustering node rabbit@node3 with rabbit@node01 ... ...done. [root@node3 ~]# rabbitmqctl start_app Starting node rabbit@node3 ... ...done. [root@node3 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node3 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2,rabbit@node3]}]}, {running_nodes,[rabbit@node01,rabbit@node3]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node3 ~]#
停掉node01上的應用
[root@node01 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node01 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2,rabbit@node3]}]}, {running_nodes,[rabbit@node3,rabbit@node01]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node01 ~]# rabbitmqctl stop_app Stopping node rabbit@node01 ... ...done. [root@node01 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node01 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2,rabbit@node3]}]}] ...done. [root@node01 ~]#
啓動node2上的應用
[root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2]}]}] ...done. [root@node2 ~]# rabbitmqctl start_app Starting node rabbit@node2 ... BOOT FAILED =========== Error description: {could_not_start,rabbit, {bad_return, {{rabbit,start,[normal,[]]}, {'EXIT', {rabbit,failure_during_boot, {error, {timeout_waiting_for_tables, [rabbit_user,rabbit_user_permission,rabbit_vhost, rabbit_durable_route,rabbit_durable_exchange, rabbit_runtime_parameters, rabbit_durable_queue]}}}}}}} Log files (may contain more information): /var/log/rabbitmq/rabbit@node2.log /var/log/rabbitmq/rabbit@node2-sasl.log Error: {rabbit,failure_during_boot, {could_not_start,rabbit, {bad_return, {{rabbit,start,[normal,[]]}, {'EXIT', {rabbit,failure_during_boot, {error, {timeout_waiting_for_tables, [rabbit_user,rabbit_user_permission, rabbit_vhost,rabbit_durable_route, rabbit_durable_exchange, rabbit_runtime_parameters, rabbit_durable_queue]}}}}}}}} [root@node2 ~]#
提示:此時node2就啓動不起來了,這時咱們就須要用到update_cluster_nodes子命令向node3更新集羣信息,而後再次在node2上啓動應用就不會報錯了;
向node3詢問更新集羣節點信息,並啓動node2上的應用
[root@node2 ~]# rabbitmqctl update_cluster_nodes rabbit@node3 Updating cluster nodes for rabbit@node2 from rabbit@node3 ... ...done. [root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2,rabbit@node3]}]}] ...done. [root@node2 ~]# rabbitmqctl start_app Starting node rabbit@node2 ... ...done. [root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2,rabbit@node3]}]}, {running_nodes,[rabbit@node3,rabbit@node2]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node2 ~]#
提示:能夠看到更新了集羣節點信息後,在node2上查看集羣狀態信息就能夠看到node3了;此時在啓動node2上的應用就沒有任何問題;
sync_queue queue:同步指定隊列;
cancel_sync_queue queue:取消指定隊列同步
set_cluster_name name:設置集羣名稱
[root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2,rabbit@node3]}]}, {running_nodes,[rabbit@node01,rabbit@node3,rabbit@node2]}, {cluster_name,<<"rabbit@node01">>}, {partitions,[]}] ...done. [root@node2 ~]# rabbitmqctl set_cluster_name rabbit@rabbit_node02 Setting cluster name to rabbit@rabbit_node02 ... ...done. [root@node2 ~]# rabbitmqctl cluster_status Cluster status of node rabbit@node2 ... [{nodes,[{disc,[rabbit@node01,rabbit@node2,rabbit@node3]}]}, {running_nodes,[rabbit@node01,rabbit@node3,rabbit@node2]}, {cluster_name,<<"rabbit@rabbit_node02">>}, {partitions,[]}] ...done. [root@node2 ~]#
提示:在集羣任意一個節點更更名稱都會同步到其餘節點;也就是說集羣狀態信息在每一個節點都是保持一致的;
基於haproxy負載均衡rabbitmq集羣
一、安裝haproxy
[root@node3 ~]# yum install -y haproxy Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.aliyun.com * updates: mirrors.aliyun.com Resolving Dependencies --> Running transaction check ---> Package haproxy.x86_64 0:1.5.18-9.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ==================================================================================================== Package Arch Version Repository Size ==================================================================================================== Installing: haproxy x86_64 1.5.18-9.el7 base 834 k Transaction Summary ==================================================================================================== Install 1 Package Total download size: 834 k Installed size: 2.6 M Downloading packages: haproxy-1.5.18-9.el7.x86_64.rpm | 834 kB 00:00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Installing : haproxy-1.5.18-9.el7.x86_64 1/1 Verifying : haproxy-1.5.18-9.el7.x86_64 1/1 Installed: haproxy.x86_64 0:1.5.18-9.el7 Complete! [root@node3 ~]#
提示:haproxy能夠從新找個主機部署,也能夠在集羣中的某臺節點上部署;建議從新找個主機部署,這樣可避免端口衝突;
配置haproxy
提示:以上就是haproxy負載均衡rabbitmq集羣的示例,咱們經過使用haproxy的tcp模式去代理rabbitmq,而且使用輪詢的算法把請求調度到後端server上;
驗證:啓動haproxy,看看對應的端口是否處於監聽狀態,狀態頁面是否可以正常檢測到後端server是否在線?
提示:此時負載均衡就搭建好了,後續使用這個集羣,咱們就能夠把這個負載均衡上監聽的地址給用戶訪問便可;這裏要考慮一點haproxy是新的單點;
在瀏覽器打開haproxy的狀態頁看看後端server是否在線?
提示:能夠看到後端3臺rabbitmq-server都是正常在線;
中止node3上的rabbitmq,看看haproxy是否可以及時發現node3再也不線,並把它標記爲down?
提示:咱們根據haproxy對後端server作健康狀態檢查來實現rabbitmq集羣的故障轉移,因此對於rabbitmq集羣來說,它只複製消息的同步,實現數據冗餘,真正高可用仍是要靠前端的調度器實現;對於nginx負載均衡rabbitmq能夠參考ngixn對tcp協議的代理來寫配置;有關nginx負載均衡tcp應用相關話題,能夠參考本人博客http://www.javashuo.com/article/p-hsdkijpf-mm.html我這裏就不過多闡述;