mysql主主复制+keepalived

环境：mysql-master1：192.168.0.103
          mysql-master2：192.168.0.104
          mysql-VIP：192.168.0.109
          mysql version:5.7.22 
          keepalived version:1.2.1  目标使用keepalived的VIP实现mysql的高可用

1.两个服务器上的server id不要一样即可
[root@rhel64-64bit mysql]# cat /etc/my.cnf|grep -iv -e '^#' -e '^$'
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
server-id=3
log-bin=mybinlogg

2.103服务器上：
create user 'repli'@'%' identified by '123456789';
grant replication slave on *.* to 'repli'@'%'

mysql> show master status;
+------------------+----------+--------------+------------------+----------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                      |
+------------------+----------+--------------+------------------+----------------------------------------+
| mybinlogg.000007 |      904 |              |                  | 61b93c79-3cbf-11e8-93cc-54e1adb62550:1 |
+------------------+----------+--------------+------------------+----------------------------------------+
1 row in set (0.00 sec)

mysql>

  104服务器上把103设为master：
change master to master_host='192.168.0.103',master_user='repli',master_password='123456789',MASTER_LOG_FILE='mybinlogg.000007', MASTER_LOG_POS=904;
start slave；
show slave status；报错:

mysql> show slave status \G;
*************************** 1. row ***************************
               Slave_IO_State: 
                  Master_Host: 192.168.0.103
                  Master_User: repli
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mybinlogg.000007
          Read_Master_Log_Pos: 904
               Relay_Log_File: rhel64-64bit-relay-bin.000001
                Relay_Log_Pos: 4
        Relay_Master_Log_File: mybinlogg.000007
             Slave_IO_Running: No
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
                Last_IO_Errno: 1593
                Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work.

解决办法：/var/lib/mysql/auto.cnf  里面的uuid和103服务器一样----》mv auto.cnf auto.cnf.bak 重启mysql服务自动生成新的uuid

3.在104服务器上：
create user 'repli'@'%' identified by '123456789';
grant replication slave on *.* to 'repli'@'%'；

mysql> show master status;
+------------------+----------+--------------+------------------+----------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                      |
+------------------+----------+--------------+------------------+----------------------------------------+
| mybinlogg.000011 |      597 |              |                  | 61b93c79-3cbf-11e8-93cc-54e1adb62550:1 |
+------------------+----------+--------------+------------------+----------------------------------------+
1 row in set (0.00 sec)

  103服务器上把104设为master：
change master to master_host='192.168.0.104',master_user='repli',master_password='123456789',MASTER_LOG_FILE='mybinlogg.000011', MASTER_LOG_POS=597;
start slave；
show slave status；

4.103服务器创建一个新的root2，会自动同步到104服务器此时
create user 'root2'@'%' identified by 'password2';
grant all privileges on *.* to 'root2';
flush privileges;

5.两个服务器上安装keepalived：yum install -y keepalived

6.103上的/etc/keepalived/keepalived.conf文件的配置：

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    nopreempt  ---只在优先级高的设置nopreempt
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.0.109/24
    }
}

virtual_server 192.168.0.109 3306 {  
      delay_loop 2 
      lb_algo wrr   
      lb_kind DR    
      persistence_timeout 60   
      protocol TCP  
      real_server 192.168.0.103 3306 {  
      weight 3  
      notify_down /usr/share/mysql/monitor.sh  ----里面就只有一行pkill keepalived,即检测到3306端口down就kill到keepalived
      TCP_CHECK {  
      connect_timeout 10    
      nb_get_retry 3       
      delay_before_retry 3   
      connect_port 3306   
      }  
     } 

启动服务service keepalived start

6.104服务器上的keepalived.conf文件配置：同上，只是修改一下
priority 90
real_server 192.168.0.104 3306
启动服务service keepalived start

7.现在vip在103服务器上：

  ip addr
  2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:22:98:4d brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.103/24 brd 192.168.0.255 scope global eth0
    inet 192.168.0.109/24 scope global secondary eth0
    inet6 fe80::20c:29ff:fe22:984d/64 scope link 
       valid_lft forever preferred_lft forever

1>以vip109连接mysql：

[root@rhel64-64bit Desktop]# mysql -uroot2 -h192.168.0.109 -p
Enter password: 
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>

2>103上停止mysql服务，检查keepalived是否停止：

[root@rhel64-64bit Desktop]# service mysqld stop
Stopping mysqld:                                           [  OK  ]
[root@rhel64-64bit Desktop]# service keepalived status
keepalived dead but subsys locked

 发现vip已经到了104服务器上了：

2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:5c:b2:0e brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.104/24 brd 192.168.0.255 scope global eth0
    inet 192.168.0.109/24 scope global secondary eth0
    inet6 fe80::20c:29ff:fe5c:b20e/64 scope link 
       valid_lft forever preferred_lft forever

3>启动103服务器上的mysql和keepalived后，再停止104服务器上的mysql，此时的VIP回到了103服务器，切换过程需要几秒,mysql这时会连不上服务器的错误：

mysql> show databases;
ERROR 2013 (HY000): Lost connection to MySQL server during query
mysql> show databases;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    60
Current database: *** NONE ***

+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
| test2              |
| wuwei              |
+--------------------+
7 rows in set (0.07 sec)