redis+Keepalived主从热备秒级切换

一 简介

安装使用centos 5.10

Master 192.168.235.135

Slave 192.168.235.152

Vip 192.168.235.200

编译环境 yum -y install gcc gcc+ gcc-c++ openssl openssl-devel pcre pcre-devel

当 Master 与 Slave 均运作正常时, Master负责服务，Slave负责Standby； 
当 Master 挂掉，Slave 正常时, Slave接管服务，同时关闭主从复制功能； 
当 Master 恢复正常，则从Slave同步数据，同步数据之后关闭主从复制功能，恢复Master身份，于此同时Slave等待Master同步数据完成之后，恢复Slave身份。 
然后依次循环。

需要注意的是，这样做需要在Master与Slave上都开启本地化策略，否则在互相自动切换的过程中，未开启本地化的一方会将另一方的数据清空，造成数据完全丢失

二 安装

Redis安装配置->:  http://liuyieyer.iteye.com/blog/2078093

下载安装wget  http://www.keepalived.org/software/keepalived-1.2.12.tar.gz

tar xf keepalived-1.2.12.tar.gz

cd keepalived-1.2.12

./configure

make && make install

cp /usr/local/etc/rc.d/init.d/keepalived /etc/init.d/

cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/

chmod +x /etc/init.d/keepalived

chkconfig –add keepalived

mkdir /etc/keepalived

ln –s /usr/local/sbin/keepalived /usr/sbin

三 配置

首先在master上创建如下配置

mkdir –p /etc/keepalived

vim /etc/keepalived/keepalived.conf

//加入如下内容脚本

vrrp_script chk_redis {

script "/etc/keepalived/scripts/redis_check.sh"   ###监控脚本

interval 2                                        ###监控时间

}

vrrp_instance VI_1 {

state MASTER                            ###设置为MASTER

interface eth0                          ###监控网卡

virtual_router_id 51

priority 101                            ###权重值

authentication {

auth_type PASS             ###加密

auth_pass redis            ###密码

}

track_script {

chk_redis                       ###执行上面定义的chk_redis

}

virtual_ipaddress {

192.168.235.200                         ###VIP

}

notify_master /etc/keepalived/scripts/redis_master.sh

notify_backup /etc/keepalived/scripts/redis_backup.sh

notify_fault  /etc/keepalived/scripts/redis_fault.sh

notify_stop   /etc/keepalived/scripts/redis_stop.sh

}

vim /etc/keepalived/scripts/redis_master.sh

#!/bin/bash

REDISCLI="/opt/redis/bin/redis-cli"

LOGFILE="/var/log/keepalived-redis-state.log"

echo "[master]" >> $LOGFILE

date >> $LOGFILE

echo "Being master...." >> $LOGFILE 2>&1

echo "Run SLAVEOF cmd ..." >> $LOGFILE

$REDISCLI SLAVEOF 192.168.135.152(slave) 6379 >> $LOGFILE  2>&1

sleep 10 #延迟10秒以后待数据同步完成后再取消同步状态

echo "Run SLAVEOF NO ONE cmd ..." >> $LOGFILE

$REDISCLI SLAVEOF NO ONE >> $LOGFILE 2>&1

vim /etc/keepalived/scripts/redis_backup.sh

#!/bin/bash

REDISCLI="/opt/redis/bin/redis-cli"

LOGFILE="/var/log/keepalived-redis-state.log"

echo "[backup]" >> $LOGFILE

date >> $LOGFILE

echo "Being slave...." >> $LOGFILE 2>&1

sleep 15 #延迟15秒待数据被对方同步完成之后再切换主从角色

echo "Run SLAVEOF cmd ..." >> $LOGFILE

$REDISCLI SLAVEOF 192.168.135.152(slave)  6379 >> $LOGFILE  2>&1

在slave上创建如下文件：

vim /etc/keepalived/keepalived.conf

vrrp_script chk_redis {

script "/etc/keepalived/scripts/redis_check.sh"   ###监控脚本

interval 2                                        ###监控时间

}

vrrp_instance VI_1 {

state BACKUP                                ###设置为BACKUP

interface eth0                              ###监控网卡

virtual_router_id 51

priority 100                                ###比MASTRE权重值低

authentication {

auth_type PASS

auth_pass redis                ###密码与MASTRE相同

}

track_script {

chk_redis                       ###执行上面定义的chk_redis

}

virtual_ipaddress {

192.168.235.200                         ###VIP

}

notify_master /etc/keepalived/scripts/redis_master.sh

notify_backup /etc/keepalived/scripts/redis_backup.sh

notify_fault  /etc/keepalived/scripts/redis_fault.sh

notify_stop   /etc/keepalived/scripts/redis_stop.sh

}

vim /etc/keepalived/scripts/redis_master.sh

#!/bin/bash

REDISCLI="/opt/redis/bin/redis-cli"

LOGFILE="/var/log/keepalived-redis-state.log"

echo "[master]" >> $LOGFILE

date >> $LOGFILE

echo "Being master...." >> $LOGFILE 2>&1

echo "Run SLAVEOF cmd ..." >> $LOGFILE

$REDISCLI SLAVEOF 192.168.235.135(master) 6379 >> $LOGFILE  2>&1

sleep 10 #延迟10秒以后待数据同步完成后再取消同步状态

echo "Run SLAVEOF NO ONE cmd ..." >> $LOGFILE

$REDISCLI SLAVEOF NO ONE >> $LOGFILE 2>&1

vim /etc/keepalived/scripts/redis_backup.sh

#!/bin/bash

REDISCLI="/opt/redis/bin/redis-cli"

LOGFILE="/var/log/keepalived-redis-state.log"

echo "[backup]" >> $LOGFILE

date >> $LOGFILE

echo "Being slave...." >> $LOGFILE 2>&1

sleep 15 #延迟15秒待数据被对方同步完成之后再切换主从角色

echo "Run SLAVEOF cmd ..." >> $LOGFILE

$REDISCLI SLAVEOF 10.6.1.143 6379 >> $LOGFILE  2>&1

以下脚本分别在master和slave上创建

mkdir /etc/keepalived/scripts

vim /etc/keepalived/scripts/redis_check.sh

#!/bin/bash

ALIVE=`/opt/redis/bin/redis-cli PING`

if [ "$ALIVE" == "PONG" ]; then

echo $ALIVE

exit 0

else

echo $ALIVE

exit 1

fi

vim /etc/keepalived/scripts/redis_fault.sh

#!/bin/bash

LOGFILE=/var/log/keepalived-redis-state.log

echo "[fault]" >> $LOGFILE

date >> $LOGFILE

vim /etc/keepalived/scripts/redis_stop.sh

#!/bin/bash

LOGFILE=/var/log/keepalived-redis-state.log

echo "[stop]" >> $LOGFILE

date >> $LOGFILE

授执行权  chmod +x /etc/keepalived/scripts/*.sh

测试

在msater和slave上分别启动redis；

Service redis start

分别启动keepalived

Service keepalived start

在master上执行 ip a

虚拟IP已经绑定了

在master上执行service redis stop 查看slave

看到了吧秒级切换。

接下来再吧master上的redis启动起来

又切换回来了。

测试redis同步

到此安装完成了。