redis+Keepalived主從熱備秒級切換

一 簡介

安裝使用centos 5.10 

Master 192.168.235.135

Slave 192.168.235.152

Vip 192.168.235.200

編譯環境 yum -y install gcc gcc+ gcc-c++ openssl openssl-devel pcre pcre-devel

 

當 Master 與 Slave 均運作正常時, Master負責服務，Slave負責Standby； 
當 Master 掛掉，Slave 正常時, Slave接管服務，同時關閉主從復制功能； 
當 Master 恢復正常，則從Slave同步數據，同步數據之后關閉主從復制功能，恢復Master身份，於此同時Slave等待Master同步數據完成之后，恢復Slave身份。 
然后依次循環。

需要注意的是，這樣做需要在Master與Slave上都開啟本地化策略，否則在互相自動切換的過程中，未開啟本地化的一方會將另一方的數據清空，造成數據完全丟失

二 安裝

Redis安裝配置->:  http://liuyieyer.iteye.com/blog/2078093

下載安裝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上創建如下配置

mkdir –p /etc/keepalived

 vim /etc/keepalived/keepalived.conf

//加入如下內容腳本

vrrp_script chk_redis { 

                script "/etc/keepalived/scripts/redis_check.sh"   ###監控腳本 

                interval 2                                        ###監控時間 

} 

vrrp_instance VI_1 { 

        state MASTER                            ###設置為MASTER

        interface eth0                          ###監控網卡    

        virtual_router_id 51

        priority 101                            ###權重值

        authentication { 

                     auth_type PASS             ###加密 

                     auth_pass redis            ###密碼 

        } 

        track_script { 

                chk_redis                       ###執行上面定義的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 #延遲10秒以后待數據同步完成后再取消同步狀態

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 #延遲15秒待數據被對方同步完成之后再切換主從角色

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

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

 

在slave上創建如下文件：

vim /etc/keepalived/keepalived.conf

vrrp_script chk_redis { 

                script "/etc/keepalived/scripts/redis_check.sh"   ###監控腳本 

                interval 2                                        ###監控時間 

} 

vrrp_instance VI_1 { 

        state BACKUP                                ###設置為BACKUP 

        interface eth0                              ###監控網卡

        virtual_router_id 51 

        priority 100                                ###比MASTRE權重值低 

        authentication { 

                     auth_type PASS 

                     auth_pass redis                ###密碼與MASTRE相同

        } 

        track_script { 

                chk_redis                       ###執行上面定義的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 #延遲10秒以后待數據同步完成后再取消同步狀態

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 #延遲15秒待數據被對方同步完成之后再切換主從角色

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

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

 

以下腳本分別在master和slave上創建

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

 

授執行權  chmod +x /etc/keepalived/scripts/*.sh

 

測試

在msater和slave上分別啟動redis；

Service redis start

分別啟動keepalived

Service keepalived start

在master上執行 ip a

虛擬IP已經綁定了

在master上執行service redis stop 查看slave

看到了吧秒級切換。

接下來再吧master上的redis啟動起來

  

又切換回來了。

測試redis同步

  
 
 

到此安裝完成了。