搭建MYSQL-MHA环境

• 准备工作

  1. 4台机器（可以是虚拟机）

  一台安装centos6.X（管理机192.168.2.5），其余三台安装centos7.X（一台主master192.168.2.6，一台主备backup192.168.2.7，一台从slave192.168.2.8）

  2. 配置epel源（配置该源时检测是否可连接）：

  [root@localhost ~]# rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
  

  3. 建立ssh无密码登录环境（4台机器均需要）

  [root@localhost ~]# ssh-keygen -t rsa
  [root@localhost ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected]
  [root@localhost ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected]
  [root@localhost ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected]
  [root@localhost ~]# ssh-copy-id -i .ssh/id_rsa.pub [email protected]
  

• 安装mysql

  1. 安装mysql（除了管理机）

  这里安装的是MariaDB
  

  2. 修改mysql配置

  • master机器

  [root@localhost ~]# vi /etc/my.cnf.d/server.cnf
  [mysqld]
  server_id = 1
  character-set-server = utf8
  lower_case_table_names = 1
  log-bin = binlog
  log-slave-updates
  [root@localhost ~]# service mysqld restart
  

  • backup机器

  [root@localhost ~]# vi /etc/my.cnf.d/server.cnf
  [mysqld]
  server_id = 2
  character-set-server = utf8
  lower_case_table_names = 1
  log-bin = binlog
  log-slave-updates
  [root@localhost ~]# service mysqld restart
  

  • slave机器

  [root@localhost ~]# vi /etc/my.cnf.d/server.cnf
  [mysqld]
  server_id = 3
  character-set-server = utf8
  lower_case_table_names = 1
  log-bin = binlog
  log-slave-updates
  read_only = 1
  [root@localhost ~]# service mysqld restart
  

  3. 登陆mysql

  • master机器

  [root@localhost ~]# mysql -uroot -p123456
  MariaDB [mysql]> CREATE USER 'weimo'@'%' IDENTIFIED BY 'weimo';
  MariaDB [mysql]> grant all privileges  ON *.* TO 'weimo'@'%' identified by "weimo";
  MariaDB [mysql]> flush privileges;
  [root@localhost ~]# mysqldump -uroot -p123456 -A -x > /tmp/full.sql
  [root@localhost ~]# scp /tmp/full.sql [email protected]:/tmp/
  [root@localhost ~]# scp /tmp/full.sql [email protected]:/tmp/
  MariaDB [mysql]> show master status;
  

  • backup机器、slave机器

  [root@localhost ~]# mysql -uroot -p123456
  MariaDB [mysql]> change master to master_host='192.168.2.6',master_port=3306,master_user='weimo',master_password='weimo',master_log_file='binlog.000003',master_log_pos=995;
  MariaDB [mysql]> start slave;
  MariaDB [mysql]> show slave status \G
  只要看到Slave_IO_Running Slave_SQL_Running都为yes就可以了。
  

  4. 赋权

  • 三台机器

  MariaDB [mysql]> grant all privileges  ON *.* TO 'weimo'@'%' identified by "weimo";
  MariaDB [mysql]> FLUSH PRIVILEGES;
  

• 安装mha

  backup机器、slave机器

  [root@localhost ~]# yum install perl-DBD-MySQL
  [root@localhost ~]# rpm -ivh mha4mysql-node-0.56-0.el6.noarch.rpm 
  （需要把安装包传上去，如安装时有报错依赖，则需要对应进行yum把依赖装上）
  

  master机器

  [root@localhost ~]# yum -y install perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager
  [root@localhost ~]# rpm -ivh mha4mysql-manager-0.56-0.el6.noarch.rpm 
  （需要把安装包传上去，如安装时有报错依赖，则需要对应进行yum把依赖装上）
  
  新建配置文件
  [root@localhost ~]# vi /etc/mha/mha.conf
  [server default]
  user=weimo
  password=weimo
  ssh_user=root
  manager_log=/usr/local/mha/manager.log
  # working directory on the manager
  manager_workdir=/usr/local/mha
  # working directory on MySQL servers
  remote_workdir=/usr/local/mha
  repl_user=weimo
  repl_password=weimo
  
  [server1]
  hostname=192.168.2.6
  
  [server2]
  hostname=192.168.2.7
  candidate_master=1
  
  [server3]
  hostname=192.168.2.8
  no_master=1
  
  检查下SSH公钥免密码登录，结果都OK就行
  [root@localhost ~]# masterha_check_ssh --conf=/etc/mha/mha.conf
  
  再检查下MySQL复制，最后提示MySQL Replication Health is OK.就行
  masterha_check_repl --conf=/etc/mha/mha.conf
  
  后台开启HA进程
  nohup masterha_manager --conf=/etc/mha/mha.conf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/mha/manager.log 2>&1 &
  

• 配置keepalived

  1. 通过yum安装

  [root@localhost ~]# yum -y install keepalived
  

  2. 修改配置文件

  • master机器

  [root@localhost ~]# vi /etc/keepalived/keepalived.conf
  global_defs {
     notification_email {
       [email protected]
       [email protected]
       [email protected]
     }
     notification_email_from [email protected]
     smtp_server 192.168.200.1
     smtp_connect_timeout 30
     router_id LVS_DEVEL
  }
  
  vrrp_instance VI_1 {
      state BACKUP
      nopreempt
      interface eno16780032
      virtual_router_id 51
      priority 100
      advert_int 1
      authentication {
          auth_type PASS
          auth_pass 1111
      }
      virtual_ipaddress {
          192.168.2.10
      }
  }
  

  • backup机器

  [root@localhost ~]# vi /etc/keepalived/keepalived.conf
  global_defs {
     notification_email {
       [email protected]
       [email protected]
       [email protected]
     }
     notification_email_from [email protected]
     smtp_server 192.168.200.1
     smtp_connect_timeout 30
     router_id LVS_DEVEL
  }
  
  vrrp_instance VI_1 {
      state BACKUP
      nopreempt
      interface eno16780032
      virtual_router_id 51
      priority 90
      advert_int 1
      authentication {
          auth_type PASS
          auth_pass 1111
      }
      virtual_ipaddress {
          192.168.2.10
      }
  }
  

  • 区别与注释

  区别：priority（优先级）不同
  注释：
      state：
          状态用的都是BACKUP，取值还有MASTER，区别在于重新连上后，MASTER会抢占vip，而BACKUP不会，直到别的VIP宕机后才会变成VIP
      interface：
          网卡名称
      virtual_router_id：
          这个id需要两个keepalived保持一致，并且同一个局域网内，id不能相同。
      virtual_ipaddress：
          这个就是虚拟ip，可以配置多个，需要保持一致
  

  3. 启动keepalived

  [root@localhost ~]# service keepalived start
  注意：需要在master机器上启动成功后，再去backup机器上启动。否则会造成操作的不是master数据库，从而导致集群无法保证正常工作，数据不一致，主从同步失败。
  

• 参考文档

  • 技术实战：基于 MHA 方式实现 MySQL 的高可用
  • MySQL高可用架构之MHA
  • Slave_SQL_Running: No mysql同步故障解决方法