Keepalived+MySQL双主高可用配置

1.安装环境：

服务器	IP	OS	MySQL同步用户名/密码	VIP
master1	192.168.0.110	CentOS 7.5	sync/syncpwd	192.168.0.250
master2	192.168.0.111	CentOS 7.5	sync/syncpwd	192.168.0.250

MySQL:5.7

Keepalived:2.0.10，VIP：192.168.0.250

MySQL安装参考CentOS 7.5安装MySQL 5.7教程 免安装版

Keepalived安装参考CentOS 7.5安装Keepalived教程

2.MySQL双主配置

服务器中已经成功安装MySQL服务器

master1修改my.cnf,新增以下配置：

>vim /etc/my.cnf
[msqyld]
server-id=110
log-bin=mysql-bin
sync-binlog=1
binlog-checksum=none
binlog-format=mixed
auto-increment-increment=2
auto-increment-offset=1
log-slave-updates
slave-skip-errors=all

master2修改my.cnf,新增以下配置：

>vim /etc/my.cnf
[msqyld]
server-id=111
log-bin=mysql-bin
sync-binlog=1
binlog-checksum=none
binlog-format=mixed
auto-increment-increment=2
auto-increment-offset=2
log-slave-updates
slave-skip-errors=all

master1和master2重启MySQL服务:

>service mysqld restart

master1和master2新增同步帐户，见MySQL安装参考

在master1中为mysql从库帐户受权：

>grant replication slave on *.* to 'sync'@'%' identified by 'syncpwd';
>flush privileges;
>show master status; #当前主库状态,即master1
show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000004 |      599 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+

在master2中为mysql从库帐户受权：

>grant replication slave on *.* to 'sync'@'%' identified by 'syncpwd';
>flush privileges;
>show master status; #当前主库状态,即master2
show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000002 |      468 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+

在maste1中指定master2为主库：

>stop slave;
>change master to master_host='192.168.0.111',master_user='sync',master_password='syncpwd',master_log_file='mysql-bin.000002',master_log_pos=468;
>flush privileges;

在maste2中指定master1为主库：

>stop slave;
>change master to master_host='192.168.0.110',master_user='sync',master_password='syncpwd',master_log_file='mysql-bin.000004',master_log_pos=599;
>flush privileges;

MySQL双主配置完成，验证配置成功：

>show slave status\G #master1中显示的信息
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.0.111
                  Master_User: sync
                  Master_Port: 3306
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
>show slave status\G #master2中显示的信息
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.0.110
                  Master_User: sync
                  Master_Port: 3306
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

在任一服务器中建立数据库表或写入数据均可以在另外一服务器中看到

3.Keepalived高可用配置

master1和master2中已经正确安装Keepalived，并指定VIP：192.168.0.250，且keepalived可正常漂移

master1修改keepalived.conf，新增配置：

>vim /etc/keepalived/keepalived.conf
virtual_server 192.168.0.250 3306 {
  delay_loop 3
  lb_algo wrr
  lb_kind DR
  persistence_timeout 60
  protocol TCP
  real_server 192.168.0.110 3306 {
    weight 3
    notify_down /usr/local/mysql/chk_mysql.sh
    TCP_CHECK {
      connect_timeout 10
      nb_get_retry 3
      delay_before_retry 3
      connect_port 3306
    }
  }
}

chk_mysql.sh内容

>vim /usr/local/mysql/chk_mysql.sh
#!/bin/bash
pkill keepalived
sleep 30
/etc/init.d/keeplived start

master2修改keepalived.conf，新增配置：

>vim /etc/keepalived/keepalived.conf
virtual_server 192.168.0.250 3306 {
  delay_loop 3
  lb_algo wrr
  lb_kind DR
  persistence_timeout 60
  protocol TCP
  real_server 192.168.0.111 3306 {
    weight 3
    notify_down /usr/local/mysql/chk_mysql.sh
    TCP_CHECK {
      connect_timeout 10
      nb_get_retry 3
      delay_before_retry 3
      connect_port 3306
    }
  }
}

chk_mysql.sh内容

>vim /usr/local/mysql/chk_mysql.sh
#!/bin/bash
pkill keepalived
sleep 30
/etc/init.d/keeplived start

4.测试

交叉验证，重启MySQL服务器后须要手动启动Keepalived