Keepalived-mysql高可用架构(主主热备)
master：192.168.8.131
backup：192.168.8.132
VIP：192.168.8.100
安装Keepalived工具
分别在master和backup服务器上安装Keepalived工具：
[[email protected] ~]# yum install -y keepalived
开始配置
配置master服务器：
配置Keepalived：
[[email protected] ~]# vim /etc/keepalived/keepalived.conf
! Configuration File forkeepalived
global_defs {
notification_email {
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id MYSQL_HA #标识，双主相同
}
vrrp_instance VI_1 {
state BACKUP #两台都设置BACKUP
interface ens33
virtual_router_id 51 #主备相同
priority 100 #优先级，backup设置90
advert_int 1
nopreempt #不主动抢占资源，只在master这台优先级高的设置，backup不设置
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.8.100
}
}
virtual_server 192.168.8.100 3306 {
delay_loop 2
#lb_algo rr #LVS算法，用不到，我们就关闭了
#lb_kind DR #LVS模式，如果不关闭，备用服务器不能通过VIP连接主MySQL
persistence_timeout 50 #同一IP的连接60秒内被分配到同一台真实服务器
protocol TCP
}
real_server 192.168.8.131 3306 { #检测本地mysql，backup也要写检测本地mysql
weight 3
notify_down /usr/local/sbin/keepalived/mysql.sh #当mysq服down时，执行此脚本，杀死keepalived实现切换
TCP_CHECK {
connect_timeout 3 #连接超时
nb_get_retry 3 #重试次数
delay_before_retry 3 #重试间隔时间
}
}
创建mysql.sh脚本：
[[email protected] ~]# mkdir /usr/local/sbin/keepalived
[[email protected] ~]# vim /usr/local/sbin/keepalived/mysql.sh
#!/bin/bash
pkill keepalived
更改文件权限：
[[email protected] ~]# chmod 755 /usr/local/sbin/keepalived/mysql.sh
启动Keepalived：
[[email protected] ~]# systemctl start keepalived
配置backup服务器：
配置Keepalived：
! Configuration File forkeepalived
global_defs {
notification_email {
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id MYSQL_HA #标识，双主相同
}
vrrp_instance VI_1 {
state BACKUP #两台都设置BACKUP
interface ens33
virtual_router_id 51 #主备相同
priority 90 #优先级，backup设置90
advert_int 1
# nopreempt #不主动抢占资源，只在master这台优先级高的设置，backup不设置
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
192.168.8.100
}
}
virtual_server 192.168.8.100 3306 {
delay_loop 2
#lb_algo rr #LVS算法，用不到，我们就关闭了
#lb_kind DR #LVS模式，如果不关闭，备用服务器不能通过VIP连接主MySQL
persistence_timeout 50 #同一IP的连接60秒内被分配到同一台真实服务器
protocol TCP
}
real_server 192.168.8.132 3306 { #检测本地mysql，backup也要写检测本地mysql
weight 3
notify_down /usr/local/sbin/keepalived/mysql.sh #当mysq服down时，执行此脚本，杀死keepalived实
现切换
TCP_CHECK {
connect_timeout 3 #连接超时
nb_get_retry 3 #重试次数
delay_before_retry 3 #重试间隔时间
}
}
创建mysql.sh文件：
[[email protected] ~]# mkdir /usr/local/sbin/keepalived
[[email protected] ~]# vim /usr/local/sbin/keepalived/mysql.sh
#!/bin/bash
pkill keepalived
更改权限：
[[email protected] ~]# chmod 755 /usr/local/sbin/keepalived/mysql.sh
启动Keepalived：
[[email protected] ~]# systemctl start keepalived
说明： backup服务器与master服务器Keepalived配置文件的区别：只修改priority为90、nopreempt不设置、real_server设置本地IP。
测试
如果服务器宕机，Keepalived服务肯定回停止工作，所以在此通过开/关Keepalived来模拟宕机状态：
宕机前：
查看master服务器IP状态：
[[email protected] ~]# ip add
2: ens33: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:8a:1b:5c brd ff:ff:ff:ff:ff:ff
inet 192.168.8.131/24 brd 192.168.8.255 scope global ens33
valid_lft forever preferred_lft forever
inet 192.168.8.100/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::65d2:adc:20d3:8c74/64 scope link
valid_lft forever preferred_lft forever
查看backup服务器IP状态：
[[email protected] ~]# ip add
2: ens33: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:af:b7:9f brd ff:ff:ff:ff:ff:ff
inet 192.168.8.132/24 brd 192.168.8.255 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::76c1:b882:4f26:608c/64 scope link
valid_lft forever preferred_lft forever
说明： 此时VIP在master服务器上，说明有master对外提供服务。
master服务器宕机后：
[[email protected] ~]# systemctl stop keepalived
查看master服务器IP：
[[email protected] ~]# ip add
2: ens33: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:8a:1b:5c brd ff:ff:ff:ff:ff:ff
inet 192.168.8.131/24 brd 192.168.8.255 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::65d2:adc:20d3:8c74/64 scope link
valid_lft forever preferred_lft forever
查看backup服务器IP：
[[email protected] ~]# ip add
2: ens33: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:af:b7:9f brd ff:ff:ff:ff:ff:ff
inet 192.168.8.132/24 brd 192.168.8.255 scope global ens33
valid_lft forever preferred_lft forever
inet 192.168.8.100/32 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::76c1:b882:4f26:608c/64 scope link
valid_lft forever preferred_lft forever
即，此时有backup服务器接管master服务器对外提供服务。
恢复master服务器Keepalived服务：
[[email protected] ~]# systemctl start keepalived
[[email protected] ~]# ip add
2: ens33: mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:0c:29:8a:1b:5c brd ff:ff:ff:ff:ff:ff
inet 192.168.8.131/24 brd 192.168.8.255 scope global ens33
valid_lft forever preferred_lft forever
inet6 fe80::65d2:adc:20d3:8c74/64 scope link
valid_lft forever preferred_lft forever
此时VIP并没有回到master服务器上，原因是master在进行Keepalived的时候加入了参数nopreemt。
以上服务器切换过程也可以通过查看日志/var/logs/messages来了解。