使用keepalived实现mysql主从复制的自动切换

使用Keepalived实现MySQL主从复制的自动切换通常涉及配置一个虚拟IP（VIP）作为MySQL服务器对客户端的访问点。Keepalived会监控MySQL主服务器的健康状况，如果主服务器宕机，Keepalived会自动将虚拟IP移至备用服务器，从而实现故障转移。

以下是一个简化的示例配置，假设您已经有两台配置好的MySQL主从服务器（master和slave）和相应的Keepalived。

在master服务器上的Keepalived配置 (/etc/keepalived/keepalived.conf):

! Configuration File for keepalivedglobal_defs {
router_id MySQL-HA
}vrrp_script check_mysql {
script "/etc/keepalived/check_mysql.sh"
interval 2
weight 2
}vrrp_instance mysql-ha {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
check_mysql
}
virtual_ipaddress {
192.168.1.200/24 dev eth0 label eth0:1
}
}

在slave服务器上的Keepalived配置 (/etc/keepalived/keepalived.conf):

! Configuration File for keepalivedglobal_defs {
router_id MySQL-HA
}vrrp_script check_mysql {
script "/etc/keepalived/check_mysql.sh"
interval 2
weight 2
}vrrp_instance mysql-ha {
state BACKUP
interface eth0
virtual_router_id 51
priority 90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
check_mysql
}
virtual_ipaddress {
192.168.1.200/24 dev eth0 label eth0:1
}
}

check_mysql.sh 脚本（位于/etc/keepalived/check_mysql.sh）:

bash#!/bin/bash
if ! mysql -u root -p'your_password' -e "show status;" &>/dev/null; then
exit 1
fi
exit 0

确保将your_password替换为您的MySQL root用户密码，并给check_mysql.sh脚本执行权限。

配置完成后，启动Keepalived服务，并确保它们随系统启动。当主服务器出现问题时，Keepalived会自动将VIP转移到备用服务器上。