搭建MySQL高可用架構MHA

 搭建MySQL高可用架構MHA v1.0

MHA簡介

MHA的主要目的是自動化master故障轉移和slave自動提高爲master，在較短期（通常爲10-30秒）的停機時間，能夠避免複製和一致性問題，不用花錢購買新的服務器，沒有性能上的損失，不復雜的（容易安裝），而且不用改變現有的部署。

MHA還提供了一個在線預約master開關的方式：改變當前正在運行的master安全的轉移到到新的mater，在幾秒鐘內的停機時間（0.5-2秒）（只支持塊寫入操做）。

MHA提供瞭如下功能，而且能夠知足許多部署的要求，如高可用性，數據完整性，不中斷master的維護

 

1.         準備測試環境

Cloud1 (192.168.100.133) Cloud2(192.168.100.216) Cloud3(192.168.100.14)

Cloud2 和Cloud3爲MHA node Cloud1爲MHA Manager

 

2.         創建3臺測試機的信任登陸關係

#cloud1(MHA manger) ssh-keygen ssh-copy-id -i ~/.ssh/id_rsa.pub cloud1 ssh-copy-id -i ~/.ssh/id_rsa.pub cloud2 ssh-copy-id -i ~/.ssh/id_rsa.pub cloud3 #cloud2  ssh-keygen ssh-copy-id -i ~/.ssh/id_rsa.pub cloud1 ssh-copy-id -i ~/.ssh/id_rsa.pub cloud2 ssh-copy-id -i ~/.ssh/id_rsa.pub cloud3 #cloud3 ssh-keygen ssh-copy-id -i ~/.ssh/id_rsa.pub cloud1 ssh-copy-id -i ~/.ssh/id_rsa.pub cloud2 ssh-copy-id -i ~/.ssh/id_rsa.pub cloud3

 

3.         下載MHA並安裝，mha4mysql-node包在全部機器上都要安裝，mha4mysql-manager包只須要在管理節點上安裝

#MHA node(cloud1 cloud2 cloud3) rpm -ivh http://dl.fedoraproject.org/pub/epel/5/i386/epel-release-5-4.noarch.rpm yum -y install perl-DBD-MySQL ncftp wget http://mysql-master-ha.googlecode.com/files/mha4mysql-node-0.53-0.noarch.rpm rpm -ivh mha4mysql-node-0.53-0.noarch.rpm   #MHA manager(cloud1) yum -y install perl-Config-Tiny perl-Params-Validate\ perl-Log-Dispatch perl-Parallel-ForkManager perl-Config-IniFiles wget http://mysql-master-ha.googlecode.com/files/mha4mysql-manager-0.53-0.noarch.rpm rpm -ivh mha4mysql-manager-0.53-0.noarch.rpm

 

4.          配置MHA 配置文件

#MHA manager(cloud1) mkdir /etc/masterha mkdir -p /masterha/app1 vi /etc/masterha/app1.cnf   [server default] user=mhauser password=mhauser123 manager_workdir=/masterha/app1 manager_log=/masterha/app1/manager.log remote_workdir=/masterha/app1 ssh_user=root repl_user=rep repl_password=rep123 ping_interval=1   [server1] hostname=192.168.100.133 ssh_port=9999 master_binlog_dir=/data no_master=1   [server2] hostname=192.168.100.216 ssh_port=9999 master_binlog_dir=/data candidate_master=1   [server3] hostname=192.168.100.14 ssh_port=9999 master_binlog_dir=/data candidate_master=1

 

5.          驗證ssh 信任登陸是否成功

#MHA manager(cloud1) masterha_check_ssh --conf=/etc/masterha/app1.cnf   Tue Jan 15 15:36:38 2013 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping. Tue Jan 15 15:36:38 2013 - [info] Reading application default configurations from /etc/masterha/app1.cnf.. Tue Jan 15 15:36:38 2013 - [info] Reading server configurations from /etc/masterha/app1.cnf.. Tue Jan 15 15:36:38 2013 - [info] Starting SSH connection tests.. …. Tue Jan 15 15:36:39 2013 - [debug]   ok. Tue Jan 15 15:36:39 2013 - [info] All SSH connection tests passed successfully. 看到successfully.代表ssh 測試成功

 

6.          首先部署3臺mysql ,創建測試庫和表，並創建起主從複製

#cloud3 爲master,cloud2爲slave1,cloud3爲slave2 #yum 安裝mysql yum –y install mysql   #設置/etc/my.cnf [client] port            = 3306 socket          = /var/lib/mysql/mysql.sock [mysqld] port            = 3306 socket          = /var/lib/mysql/mysql.sock datadir         = /data skip-locking key_buffer = 16M max_allowed_packet = 1M table_cache = 64 sort_buffer_size = 512K net_buffer_length = 8K read_buffer_size = 256K read_rnd_buffer_size = 512K myisam_sort_buffer_size = 8M skip-federated log-bin=mysql-bin server-id       = 1      #master id=1 ;slave 1 id =2; slave 2 id =3 [mysqldump] quick max_allowed_packet = 16M [mysql] no-auto-rehash [isamchk] key_buffer = 20M sort_buffer_size = 20M read_buffer = 2M write_buffer = 2M [myisamchk] key_buffer = 20M sort_buffer_size = 20M read_buffer = 2M write_buffer = 2M [mysqlhotcopy] interactive-timeout   #創建測試庫dbtest create database dbtest; #創建測試表tb1 use dbtest;   CREATE TABLE `tb1` (   `id` int(11) NOT NULL auto_increment,   `name` varchar(32) default NULL,    PRIMARY KEY  (`id`) );   #設置的複製權限賬號 GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO 'rep'@'%' IDENTIFIED BY 'rep123'; FLUSH PRIVILEGES; #創建主從複製關係 reset master; show master status;   change master to master_host='192.168.100.14', master_port=3306, master_user='rep', master_password='rep123', master_log_file='mysql-bin.000001', master_log_pos=98;   slave start; show slave status\G; show full processlists; #在master插入數據查看binlog是否同步 insert into tb1(name) values ('123');   #創建mha使用的賬號並設置權限 grant all on *.* to mhauser@'cloud1' identified by 'mhauser123'; grant all on *.* to mhauser@'cloud2' identified by 'mhauser123'; grant all on *.* to mhauser@'cloud3' identified by 'mhauser123'; FLUSH PRIVILEGES;

 

7.          驗證mysql複製是否成功

#MHA manager(cloud1) masterha_check_repl --conf=/etc/masterha/app1.cnf Tue Jan 15 16:15:22 2013 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping. Tue Jan 15 16:15:22 2013 - [info] Reading application default configurations from /etc/masterha/app1.cnf.. Tue Jan 15 16:15:22 2013 - [info] Reading server configurations from /etc/masterha/app1.cnf.. Tue Jan 15 16:15:22 2013 - [info] MHA::MasterMonitor version 0.53. Tue Jan 15 16:15:22 2013 - [info] Dead Servers: … MySQL Replication Health is OK. 看到is OK,表面mysql複製成功

 

8.          啓動並驗證MHA manager

#MHA manager(cloud1) #啓動MHA manager nohup masterha_manager --conf=/etc/masterha/app1.cnf > /tmp/mha_manager.log 2>&1 &   #驗證MHA狀態 masterha_check_status --conf=/etc/masterha/app1.cnf app1 (pid:5605) is running(0:PING_OK), master:192.168.100.14   #關閉MHA manager ps auxf|grep masterha_manager|grep -v grep|awk '{print $2}'|xargs kill

 

9.         測試master宕機後是否自動切換

#MHA node(cloud3) /etc/init.d/mysqld stop #MHA manager(cloud1) tail -f /masterha/app1/manager.log … ----- Failover Report ----- app1: MySQL Master failover 192.168.100.14 to 192.168.100.216 succeeded Master 192.168.100.14 is down! Check MHA Manager logs at cloud1:/masterha/app1/manager.log for details. Started automated(non-interactive) failover. The latest slave 192.168.100.133(192.168.100.133:3306) has all relay logs for recovery. Selected 192.168.100.216 as a new master. 192.168.100.216: OK: Applying all logs succeeded. 192.168.100.133: This host has the latest relay log events. Generating relay diff files from the latest slave succeeded. 192.168.100.133: OK: Applying all logs succeeded. Slave started, replicating from 192.168.100.216. 192.168.100.216: Resetting slave info succeeded. Master failover to 192.168.100.216(192.168.100.216:3306) completed successfully. 看到successfully.代表切換成功

 

10.     恢復原來的主數據庫爲master

#MHA node(cloud3) #創建到新master (cloud2)的同步關係 change master to master_host='192.168.100.216', master_port=3306, master_user='rep', master_password='rep123', master_log_file='mysql-bin.000002', master_log_pos=98;   #MHA manager(cloud1) ps auxf|grep masterha_manager|grep -v grep|awk '{print $2}'|xargs kill masterha_master_switch --master_state=alive --conf=/etc/masterha/app1.cnf … It is better to execute FLUSH NO_WRITE_TO_BINLOG TABLES on the master before switching. Is it ok to execute on 192.168.100.216(192.168.100.216:3306)? (YES/no):yes … Starting master switch from 192.168.100.216(192.168.100.216:3306) to 192.168.100.14(192.168.100.14:3306)? (yes/NO): yes … Wed Jan 16 13:58:10 2013 - [info]  192.168.100.14: Resetting slave info succeeded. Wed Jan 16 13:58:10 2013 - [info] Switching master to 192.168.100.14(192.168.100.14:3306) completed successfully.   #就此最簡單的master 高可用測試成功