使用Keepalived实现MySQL双主高可用(3)

vrrp_instance VI_1 {
    state BACKUP
    interface eth0            #根据实际网络接口进行更改
    virtual_router_id 51
    priority 90                #优先级，backup设置为90
    advert_int 1
    #nopreempt                #主动抢占资源
    authentication {
        auth_type PASS
        auth_pass 1111
    } 
    virtual_ipaddress {
        192.168.1.30
    } 
} 

virtual_server 192.168.1.30 3306 {
    delay_loop 2
    #lb_algo rr
    #lb_kind NAT
    persistence_timeout 50
    protocol TCP
   
    real_server 192.168.1.20 3306 {              #检测本地mysql
        weight 3
        notify_down /tmp/mysql.sh                #当mysql服务down时，执行此脚本，杀死keepalived实现切换
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
        } 
    } 
}

master 和 backup上编辑mysql.sh

# vim /tmp/mysql.sh

#!/bin/bash
pkill keepalived

# chmod +x !$
# systemctl start keepalived

两台mysql服务器授权允许root远程登录：

# mysql -uroot -p123456789

mysql> grant all on *.* to 'root'@'192.168.1.%' identified by '123456';

mysql> flush privileges;

测试高可用
通过mysql客户端通过VIP连接，看是否连接成功。
这里我用同网段的另一台机器，连接测试：

# mysql -h192.168.1.30 -uroot -p123456

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> select * from test.user;
+--------+------+
| number | name |
+--------+------+
|      1 | testid  |
+--------+------+
1 row in set (0.01 sec)
---------------------

可以看到，连接成功，且查询数据没有问题，停止master上mysql服务，是否能正常切换到backup上，可以使用 ip addr命令来查看VIP在哪台服务器上。

master上查看是否有VIP,可以看到VIP在master上

# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
      valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
      valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:cf:ab:c4 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.10/24 brd 192.168.1.255 scope global noprefixroute eth0
      valid_lft forever preferred_lft forever
    inet 192.168.1.30/32 scope global eth0
      valid_lft forever preferred_lft forever
    inet6 fe80::fe8e:3c2f:4d32:e9fd/64 scope link noprefixroute
      valid_lft forever preferred_lft forever
---------------------

停掉master上mysql服务：

# systemctl stop mysqld

# ps axu |grep keepalived
root      11074  0.0  0.0 112708  988 pts/1    S+  15:28  0:00 grep --color=autokeepalived

# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
      valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
      valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:cf:ab:c4 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.10/24 brd 192.168.1.255 scope global noprefixroute eth0
      valid_lft forever preferred_lft forever
    inet6 fe80::fe8e:3c2f:4d32:e9fd/64 scope link noprefixroute
      valid_lft forever preferred_lft forever
---------------------

可以看到，keepalived在mysql服务停掉之后也被停掉，VIP不在master上。

backup上查看是否有VIP，可以看到VIP在backup上。