1.关闭selinux
SELINUX=disabled
2.yum安装keepalived
yum install -y keepalived
3.修改配置文件
主库配置文件：
! Configuration File for keepalived
global_defs {
notification_email {
lr@isadba.com
}
notification_email_from lvs@isadba.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id mysql01
lr@isadba.com
}
notification_email_from lvs@isadba.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id mysql01
! lvs_sync_daemon eth0 VI_1 1
}
}
vrrp_instance VI_1 {
state master
priority 150
nopreempt
priority 150
nopreempt
virtual_router_id 241
interface eno16777728
advert_int 1
! smtp_alert
authentication {
auth_type PASS
auth_pass 1111
}
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.12.4
}
}
192.168.12.4
}
}
virtual_server 192.168.12.4 3306 {
delay_loop 6
lb_algo wlc
lb_kind TUN
protocol TCP
lb_algo wlc
lb_kind TUN
protocol TCP
real_server 192.168.12.60 3306 {
weight 1
notify_down /mysql/killkeepalived.sh
TCP_CHECK {
connect_port 3306
connect_timeout 3
}
}
weight 1
notify_down /mysql/killkeepalived.sh
TCP_CHECK {
connect_port 3306
connect_timeout 3
}
}
real_server 192.168.12.2 3306 {
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
}
}
}
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
}
}
}
从库配置文件：
! Configuration File for keepalived
global_defs {
notification_email {
lr@isadba.com
}
notification_email_from lvs@isadba.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id mysql02
lr@isadba.com
}
notification_email_from lvs@isadba.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id mysql02
! lvs_sync_daemon eth0 VI_1 1
}
}
vrrp_instance VI_1 {
state backup
priority 100
nopreempt
priority 100
nopreempt
virtual_router_id 241
interface eno16777728
advert_int 1
! smtp_alert
authentication {
auth_type PASS
auth_pass 1111
}
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.12.4
}
}
192.168.12.4
}
}
virtual_server 192.168.12.4 3306 {
delay_loop 6
lb_algo wlc
lb_kind TUN
protocol TCP
lb_algo wlc
lb_kind TUN
protocol TCP
real_server 192.168.12.60 3306 {
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
}
}
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
}
}
real_server 192.168.12.2 3306 {
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
}
}
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
}
}
}
主库脚本/mysql/killkeepalived.sh
#!/bin/sh
systemctl stop keepalived
systemctl stop keepalived
4.主从切换过程
1.主库停库
2.keepalived执行关闭keepalived脚本
3.恢复主库，启动主库keepalived，关闭备库keepalived，vip即可回到主库。
5.扩展
如果使用keepalived+mycat搭建主从+多个只读从库，将vip写入mycat配置schema.xml文件，业务使用vip连接数据库。