3.1安裝KEEPALIVED軟體：
wget http://www.keepalived.org/software/keepalived-1.2.7.tar.gz
tar zxvf keepalived-1.2.7.tar.gz 
cd keepalived-1.2.7
./configure --prefix=/usr/local/keepalived --with-kernel-dir=/usr/src/kernels/2.6.18-194.el5-x86_64

  3.2設定KEEPALIVED開機自啟動：
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ 
 cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ 
 cp /usr/local/keepalived/sbin/keepalived /usr/sbin/ 
 chkconfig keepalived on

  3.3編寫主從庫上的配置檔案：
mkdir /etc/keepalived
vi /etc/keepalived/keepalived.conf
資料庫角色	配置檔案內容



192.168.137.212 VIP
 
192.168.137.3  master

192.168.137.4  slave

主	! Configuration File for keepalived
global_defs {
   router_id MySQL-ha
}

#global_defs {
#notification_email {
#
 
[email protected]
}
#當主、備份裝置發生改變時，通過郵件通知
#notification_email_from [email protected]
#smtp_server stmp.126.com
#smtp_connect_timeout 30
#router_id MySQL-ha
#}

vrrp_instance VI_1{
# 在初始化狀態下定義為主裝置
state BACKUP
# 注意網絡卡介面
interface eth0
virtual_router_id 51
# 優先順序，另一臺改為90
priority 100
advert_int 1
# 不主動搶佔資源
nopreempt
authentication {
# 認證方式，可以是PASS或AH兩種認證方式
auth_type PASS
# 認證密碼
auth_pass 1111
}

virtual_ipaddress {
# 虛擬IP地址，隨著state的變化而增加刪除
192.168.137.212
}
}

virtual_server 192.168.137.212 3306 {
# 每個2秒檢查一次real_server狀態
delay_loop 2
# LVS演算法
lb_algo wrr
# LVS模式
lb_kind DR
# 會話保持時間
persistence_timeout 60
protocol TCP

real_server 192.168.137.3 3306 {
# 權重
weight 3
# 檢測到服務down後執行的指令碼
notify_down /etc/keepalived/keepalived.sh
TCP_CHECK {
# 連線超時時間
connect_timeout 10
# 重連次數
nb_get_retry 3
# 重連間隔時間
delay_before_retry 3
# 健康檢查埠
connect_port 3306
}
}
} 


從! Configuration File for keepalived

global_defs {
   router_id MySQL-ha
}

vrrp_instance VI_1{
# 在初始化狀態下定義為主裝置
state BACKUP
# 注意網絡卡介面
interface eth0
virtual_router_id 51
# 優先順序，另一臺改為90
priority 90
advert_int 1
# 不主動搶佔資源
nopreempt
authentication {
# 認證方式，可以是PASS或AH兩種認證方式
auth_type PASS
# 認證密碼
auth_pass 1111
}

virtual_ipaddress {
# 虛擬IP地址，隨著state的變化而增加刪除
192.168.137.212
}
notify_master /etc/keepalived/modifyreadonly.sh
}

virtual_server 192.168.137.212 3306 {
# 每個2秒檢查一次real_server狀態
delay_loop 2
# LVS演算法
lb_algo wrr
# LVS模式
lb_kind DR
# 會話保持時間
persistence_timeout 60
protocol TCP

real_server 192.168.137.4 3306 {
# 權重
weight 3
# 檢測到服務down後執行的指令碼
notify_down /etc/keepalived/keepalived.sh
TCP_CHECK {
# 連線超時時間
connect_timeout 10
# 重連次數
nb_get_retry 3
# 重連間隔時間
delay_before_retry 3
# 健康檢查埠
connect_port 3306
}
}
}


/etc/keepalived/keepalived.sh 內容:
/get_ssh.exp 192.168.137.4 xxxx "/apps/svr/mysql5.6/bin/mysql -uroot -pxxxxxxx -S /apps/dbdat/mysql_3306data/mysql_3306.sock -e 'set global read_only=0;'"



/etc/keepalived/modifyreadonly.sh 內容:
/usr/local/mysql/bin/mysql -uroot -pxxxxx -S /data/mysqldata/3306/mysql.sock -e 'set global read_only=0;'



192.168.137.212 

192.168.137.3 主

192.168.137.4 從


  3.4配置檢測主庫DOWN後執行的指令碼：
指令碼一	#!/bin/sh

/etc/init.d/keepalived stop 
#在停止KEEPALIVED後遠端將第二節點改為可寫
/get_ssh.exp 192.168.137.4 xxxx "/apps/svr/mysql5.6/bin/mysql -uroot -pxxxxxxx -S /apps/dbdat/mysql_3306data/mysql_3306.sock -e 'set global read_only=0;'"



指令碼二	get_ssh.exp 的內容如下： 要先安裝軟體：expect
#!/usr/bin/expect -f
set timeout -1
if { [llength $argv] < 3} {
  puts "usage: $argv0 ip pass cmd"
    exit 1
    }


set ip [lindex $argv 0 ]
set password [lindex $argv 1 ]
set cmd [lindex $argv 2 ]

spawn ssh $ip $cmd
expect {  
 "*yes/no" { send "yes\r"; exp_continue}  
 "*password:" { send "$password\r" }  
 }  
 expect eof




指令碼三	當從庫的狀態變為MASTER後所要執行的指令碼：
#!/bin/bash
/usr/local/mysql/bin/mysql -uroot -pxxxxx -S /data/mysqldata/3306/mysql.sock -e 'set global read_only=0;'