keepalived+双主架构部署

在高可用集群环境中，keepalived使用的是VIP，利用keepalived自带的服务监控功能和自定义脚本来实现MYSQL故障时自带切换。

Keepalived基于VRRP协议，虚拟冗余路由协议，所谓vrrp的优先级就是它会根据优先级来确定其他在集群中的地位，用0-255来表示，数字越小则表示优先级越低，数值越大表示优先级越高。当值为0，代表着master放弃持有VIP；该值为255时，表示当前master的优先级最高并蚩尤VIP。

1、搭建GTID+row模式双主环境

IP	主机名	作用	数据库版本	操作系统版本
172.16.20.32	mastera	master	Mysql5.7.20	Redhat6.7
172.16.20.34	masterb	master	Mysql5.7.20	Redhat6.7
172.16.20.30		VIP

1.1. MySQL GTID环境安装

此处参照以前论坛内容：

http://www.cnblogs.com/hmwh/p/9011377.html

https://www.cnblogs.com/hmwh/p/9011377.html

1.2. 分别再主备库上创建同步账号

创建主从复制账号

create user 'rep'@'172.16.20.%' identified by 'mysql';

grant replication slave on *.* to 'rep'@'172.16.20.%';

show grants for 'rep'@'172.16.20.%';

flush privileges;

所有主机创建管理账号：

create user 'zs'@'172.16.20.%' identified by '123456';

grant all privileges on *.* to 'zs'@'172.16.20.%';

flush privileges;

配置主从复制：

change master to master_host='172.16.20.32',master_port=3307,master_user='rep',master_password='mysql',master_auto_position=1;

start slave;

show slave status\G;

无问题后再在主库配置复制关系：

change master to master_host='172.16.20.34',master_port=3307,master_user='rep',master_password='mysql',master_auto_position=1;

start salve;

show slave status\G;

1.3分别安装keepalived软件包

由于我的没有keepalived包

yum install keepalived

下载地址：

http://rpmfind.net/linux/rpm2html/search.php?query=keepalived&submit=%E6%90%9C%E7%B4%A2...+&system=&arch=

rpm -ivh keepalived-1.2.13-5.el6_6.x86_64.rpm

1.4配置MYSQL数据库检测脚本

两台服务器都配置检测脚本：内容根据情况自行修改

cd /etc/keepalived/

vim checkmysql.sh

内容如下：

#!/bin/bash

mysqlstr=/usr/local/mysql5.7/bin/mysql

host=172.16.2.32

user=zs

password=123456

port=3307

#####mysql service machine status health is 1,others 0

mysql_status=1

#####check mysql status#########

$mysqlstr -h $host -u $user -p$password -P $port -e "show status;" > /dev/null 2>&1

if [ $? = 0 ];then

echo "mysql_status=1"

exit 0

else

/etc/init.d/keepalived stop

chmod 775 checkmysql.sh

1.5两台机器上修改keepalived配置文件

主库的：

vim keepalived.conf

vrrp_script vs_mysql_100 {

script "/etc/keepalived/checkmysql.sh"

interval 10

}

vrrp_instance VI_100 {

state BACKUP

nopreempt

interface eth0

virtual_router_id 100

priority 100 --注意，30的为100,34的为90。

advert_int 5

authentication {

auth_type PASS

auth_pass 1314

}

track_script {

vs_mysql_100

}

virtual_ipaddress {

172.16.20.30

}

备库的：

vim keepalived.conf

vrrp_script vs_mysql_101 {

script "/etc/keepalived/checkmysql.sh"

interval 10

}

vrrp_instance VI_101 {

state BACKUP

nopreempt

interface eth0

virtual_router_id 100

priority 90

advert_int 5

authentication {

auth_type PASS

auth_pass 1314

}

track_script {

vs_mysql_101

}

virtual_ipaddress {

172.16.20.30

}

1.6 启动keepalived

32服务器先启动。

/etc/init.d/keepalived start

/etc/init.d/keepalived status

ps -ef |grep keep

tail -100f /var/log/messages

172.16.20.32优先级高，keepalived的状态已经由backup升级为master。

ip addr

34服务器启动keepalived进程：

/etc/init.d/keepalived start

/etc/init.d/keepalived status

ps -ef |grep keep

tail -100f /var/log/messages

查看日志为backup 模式

管理用户测试登陆：

查看的UUID为主库32的。

备库keepalived 启动了，并没有VIP。

1.7故障演练

关闭32。

可以看到VIP飘到34服务器上。

且keepalived状态由backup升级为master。