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：
  1.     change master to master_host='master_ip',master_port=port,master_user='repl',master_password='xxxx',master_auto_position=1;
  • 主库配置
  1.   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

  1. yum install keepalived

安装成功后可以查看版本

  1. [root@master vagrant]# keepalived -v
  2. Keepalived v1.3.5 (03/19,2017), git commit v1.3.5-6-g6fa32f2
  4. Copyright(C) 2001-2017 Alexandre Cassen, <acassen@gmail.com>

2.更改配置文件

  1. vim /etc/keepalived/keepalived.conf
  2. [root@master keepalived]# cat keepalived.conf
  3. vrrp_script vs_mysql_82 {
  4.     script "/etc/keepalived/checkMySQL.py -h 192.168.50.3 -P 3306"
  5.     interval 60
  6. }
  7. vrrp_instance VI_82 {
  8.     state BACKUP
  9.     nopreempt
  10.     interface enp0s8
  11.     virtual_router_id 82
  12.     priority 100
  13.     advert_int 5
  14.     authentication {
  15.         auth_type PASS
  16.         auth_pass 1111
  17.     }
  18.     track_script {
  19.        vs_mysql_82
  20.     }
  21.     virtual_ipaddress {
  22.         192.168.50.5
  23.     }
  24. }

增加MySQL检查脚本

  1. [root@master keepalived]# cat checkMySQL.py
  2. #!/usr/bin/python
  3. #coding: utf-8
  4. #
  6. import sys
  7. import os
  8. import getopt
  9. import MySQLdb
  10. import logging
  14. dbhost='localhost'
  15. dbport=3306
  16. dbuser='monitor'
  17. dbpassword='m0n1tor'
  20. def checkMySQL():
  21.         global dbhost
  22.         global dbport
  23.         global dbuser
  24.         global dbpassword
  26.         shortargs='h:P:'
  27.         opts, args=getopt.getopt(sys.argv[1:],shortargs)
  28.         for opt, value in opts:
  29.                 if opt=='-h':
  30.                         dbhost=value
  31.                 elif opt=='-P':
  32.                         dbport=value
  33.         #print "host : %s, port: %d, user: %s, password: %s" % (dbhost, int(dbport), dbuser, dbpassword)
  34.         db = instanceMySQL(dbhost, dbport, dbuser, dbpassword)
  35.         st = db.ishaveMySQL()
  36.         #if ( db.connect() != 0 ):
  37.         #       return 1
  38.         #db.disconnect()
  39.         return st
  41. class instanceMySQL:
  42.         conn = None
  43.         def __init__(self, host=None,port=None, user=None, passwd=None):
  44.                 self.dbhost= host
  45.                 self.dbport = int(port)
  46.                 self.dbuser = user
  47.                 self.dbpassword = passwd
  49.         def ishaveMySQL(self):
  50.                 cmd="ps -ef | egrep -i \"mysqld\" | grep %s | egrep -iv \"mysqld_safe\" | grep -v grep | wc -l" % self.dbport
  51.                 mysqldNum = os.popen(cmd).read()
  52.                 cmd ="netstat -tunlp | grep \":%s\" | wc -l" % self.dbport
  53.                 mysqlPortNum= os.popen(cmd).read()
  54.                 #print mysqldNum, mysqlPortNum
  55.                 if ( int(mysqldNum) <= 0):
  56.                         print "error"
  57.                         return 1
  58.                 if ( int(mysqldNum) > 0 and  mysqlPortNum <= 0):
  59.                         return 1
  60.                 return 0
  62.         def connect(self):
  63.         #       print "in db conn"
  64. #               print "host : %s, port: %d, user: %s, password: %s" % (self.dbhost, self.dbport, self.dbuser, self.dbpassword)
  65.                 try:
  66.                         self.conn=MySQLdb.connect(host="%s"%self.dbhost, port=self.dbport,user="%s"%dbuser, passwd="%s"%self.dbpassword)
  67.                 except Exception, e:
  68. #                       print " Error"
  69.                         print e
  70.                         return 1
  71.                 return 0
  72.         def disconnect(self):
  73.                 if (self.conn):
  74.                         self.conn.close()
  75.                         self.conn = None
  78. if __name__== "__main__":
  79.         st=checkMySQL()
  80.         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