【MySQL】MySQL5.7+keepalived配置双主

前言：MySQL5.7+keepalived双主配置MySQL高可用相对来说是比较成熟的方案，下面我们简单来说一下主要的配置步骤。

一、配置双主

这步相对来说比较简单，我们只讨论GTID模式下的主从配置。

• 从库配置：

    change master to master_host='master_ip',master_port=port,master_user='repl',master_password='xxxx',master_auto_position=1;

• 主库配置

  change master to master_host='slave_ip',master_port=port,master_user='repl',master_password='xxxx',master_auto_position=1;

二、配置keepalived

1.安装keepalived

yum install keepalived

安装成功后可以查看版本

[root@master vagrant]# keepalived -v
Keepalived v1.3.5 (03/19,2017), git commit v1.3.5-6-g6fa32f2

Copyright(C) 2001-2017 Alexandre Cassen, 

2.更改配置文件

vim /etc/keepalived/keepalived.conf
[root@master keepalived]# cat keepalived.conf
vrrp_script vs_mysql_82 {
    script "/etc/keepalived/checkMySQL.py -h 192.168.50.3 -P 3306"
    interval 60
}
vrrp_instance VI_82 {
    state BACKUP
    nopreempt
    interface enp0s8
    virtual_router_id 82
    priority 100
    advert_int 5
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
       vs_mysql_82
    }
    virtual_ipaddress {
        192.168.50.5
    }
}

增加MySQL检查脚本

[root@master keepalived]# cat checkMySQL.py
#!/usr/bin/python
#coding: utf-8
#

import sys
import os
import getopt
import MySQLdb
import logging



dbhost='localhost'
dbport=3306
dbuser='monitor'
dbpassword='m0n1tor'


def checkMySQL():
        global dbhost
        global dbport
        global dbuser
        global dbpassword

        shortargs='h:P:'
        opts, args=getopt.getopt(sys.argv[1:],shortargs)
        for opt, value in opts:
                if opt=='-h':
                        dbhost=value
                elif opt=='-P':
                        dbport=value
        #print "host : %s, port: %d, user: %s, password: %s" % (dbhost, int(dbport), dbuser, dbpassword)
        db = instanceMySQL(dbhost, dbport, dbuser, dbpassword)
        st = db.ishaveMySQL()
        #if ( db.connect() != 0 ):
        #       return 1
        #db.disconnect()
        return st

class instanceMySQL:
        conn = None
        def __init__(self, host=None,port=None, user=None, passwd=None):
                self.dbhost= host
                self.dbport = int(port)
                self.dbuser = user
                self.dbpassword = passwd

        def ishaveMySQL(self):
                cmd="ps -ef | egrep -i \"mysqld\" | grep %s | egrep -iv \"mysqld_safe\" | grep -v grep | wc -l" % self.dbport
                mysqldNum = os.popen(cmd).read()
                cmd ="netstat -tunlp | grep \":%s\" | wc -l" % self.dbport
                mysqlPortNum= os.popen(cmd).read()
                #print mysqldNum, mysqlPortNum
                if ( int(mysqldNum) <= 0):
                        print "error"
                        return 1
                if ( int(mysqldNum) > 0 and  mysqlPortNum <= 0):
                        return 1
                return 0

        def connect(self):
        #       print "in db conn"
#               print "host : %s, port: %d, user: %s, password: %s" % (self.dbhost, self.dbport, self.dbuser, self.dbpassword)
                try:
                        self.conn=MySQLdb.connect(host="%s"%self.dbhost, port=self.dbport,user="%s"%dbuser, passwd="%s"%self.dbpassword)
                except Exception, e:
#                       print " Error"
                        print e
                        return 1
                return 0
        def disconnect(self):
                if (self.conn):
                        self.conn.close()
                        self.conn = None


if __name__== "__main__":
        st=checkMySQL()
        sys.exit(st)

从库做同样配置，注意修改绑定的网卡和真实的IP，两个节点启动keepalived即可