使用 LVS+Keepalived 实现 MySQL双主复制高可用
准备工作：
| 主机名 | 操作系统 | IP地址 | 担任角色 |
| master1 | CentOS7 | 192.168.1.1 | MySQL-主 |
| master2 | 192.168.1.2 | MySQL-主 | |
| keep1 | 192.168.1.3 | Keepalived-主，LVS | |
| keep2 | 192.168.1.4 | Keepalived-备，LVS | |
| client | 192.168.1.5 | 测试客户机 |
一、 部署 MySQL 双主复制
- 注意：未部署 MySQL 数据库需看：CentOS7 安装 MySQL 数据库 来进行安装。
1.配置时间同步
master1 上操作
[root@master1 ~]# yum -y install ntp
[root@master1 ~]# sed -i '/^server/s/^/#/g' /etc/ntp.conf
[root@master1 ~]# cat <<END >> /etc/ntp.conf
server 127.127.1.0
fudge 127.127.1.0 stratum 8
END
[root@master1 ~]# systemctl restart ntpd #重启ntpd
[root@master1 ~]# systemctl enable ntpd #设置开机自启
[root@master1 ~]# netstat -anpu | grep ntp #查看状态
master 2上操作
[root@master2 ~]# yum -y install ntpdate
[root@master2 ~]# /usr/sbin/ntpdate 192.168.1.1
2.配置双主复制
1）master1 上操作
[root@master1 ~]# cat <<END >> /etc/my.cnf
log-bin=mysql-master1
server-id=1
log_slave_update=1
auto_increment_offset=1
auto_increment_increment=2
END
[root@master1 ~]# systemctl restart mysqld
[root@master1 ~]# mysql -uroot -p123456
mysql> grant replication slave on *.* to repl@'192.168.1.%' identified by '123456';
mysql> flush privileges;
mysql> exit
2）master2 上操作
[root@master2 ~]# cat <<END >> /etc/my.cnf
log-bin=mysql-master2
server-id=2
log_slave_update=1
auto_increment_offset=1
auto_increment_increment=2
END
[root@master2 ~]# systemctl restart mysqld
[root@master2 ~]# mysql -uroot -p123456
mysql> grant replication slave on *.* to repl@'192.168.1.%' identified by '123456';
mysql> flush privileges;
mysql> exit
3）建立双主复制
master1 上操作
[root@master1 ~]# mysql -uroot -p123456
mysql> change master to
master_host='192.168.1.2',
master_user='repl',
master_password='123456';
mysql> start slave;
mysql> show slave status\G;
master2 上操作
[root@master2 ~]# mysql -uroot -p123456
mysql> change master to
master_host='192.168.1.1',
master_user='repl',
master_password='123456';
mysql> start slave;
mysql> show slave status\G;
二、部署 LVS+Keepalived 实现 MySQL 双主复制高可用
1.配置主调度器
[root@keep1 ~]# yum -y install keepalived ipvsadm
[root@keep1 ~]# vim /etc/keepalived/keepalived.conf
global_defs {
router_id 1
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.188
}
}
virtual_server 192.168.1.188 3306 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 0
protocol TCP
real_server 192.168.1.1 3306 {
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.1.2 3306 {
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
[root@keep1 ~]# systemctl start keepalived
[root@keep2 ~]# ip a
2.配置备调度器
[root@keep2 ~]# yum -y install keepalived ipvsadm
[root@keep2 ~]# vim /etc/keepalived/keepalived.conf
global_defs {
router_id 2
}
vrrp_instance VI_1 {
state BACKUP
interface ens33
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.1.188
}
}
virtual_server 192.168.1.188 3306 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 0
protocol TCP
real_server 192.168.1.1 3306 {
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.1.2 3306 {
weight 1
TCP_CHECK {
connect_port 3306
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}
[root@keep2 ~]# systemctl start keepalived
3.查看 LVS 集群状态
[root@keep1 ~]# ipvsadm -ln
4.编写 LVS 启动脚本
在 master1 master2 上操作
[root@master1 ~]# vim /etc/init.d/realserver
#!/bin/bash
VIP=192.168.1.188
. /etc/rc.d/init.d/functions
case "$1" in
start)
/sbin/ifconfig lo down
/sbin/ifconfig lo up
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
/sbin/sysctl -p >/dev/null 2>&1
/sbin/ifconfig lo:0 $VIP netmask 255.255.255.255 up
/sbin/route add -host $VIP dev lo:0
echo "LVS-DR real server starts successfully.\n"
;;
stop)
/sbin/ifconfig lo:0 down
/sbin/route del $VIP >/dev/null 2>&1
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
echo "LVS-DR real server stopped.\n"
;;
status)
isLoOn=`/sbin/ifconfig lo:0 | grep "$VIP"`
isRoOn=`/bin/netstat -rn | grep "$VIP"`
if [ "$isLoON" == "" -a "$isRoOn" == "" ]; then
echo "LVS-DR real server has run yet."
else
echo "LVS-DR real server is running."
fi
exit 3
;;
*)
echo "Usage: $0 {start|stop|status}"
exit 1
esac
exit 0
[root@master1 ~]# chmod +x /etc/init.d/realserver #添加可执行权限
[root@master1 ~]# /etc/init.d/realserver start #启动脚本
[root@master1 ~]# echo "/etc/init.d/realserver" >> /etc/rc.d/rc.local #设置开启自启动
[root@master1 ~]# ifconfig lo:0
三、验证
在任意一台 master 添加一个测试用户
[root@master1 ~]# mysql -uroot -p123456
mysql> grant all on *.* to test@'%' identified by '123123';
mysql> flush privileges;
1.验证 LVS 负载均衡是否正常
[root@client ~]# yum -y install mariadb
[root@client ~]# mysql -utest -p123123 -h192.168.1.188 -e "show variables like 'server_id'"
[root@client ~]# mysql -utest -p123123 -h192.168.1.188 -e "show variables like 'server_id'"
2.验证 Keepalived 双机热备是否正常
- 关闭 LVS 主调度器，查看客户机是否能够正常访问数据库。
3.验证 MySQL 数据库可用性
[root@master1 ~]# systemctl stop mysqld
