redis+keepalived 主从热备实例

时间：2016-07-21 22:11:40 阅读：337 评论：0 收藏：0 [点我收藏+]

标签：redis+keepalived 高可用秒级切换

qiehuan 环境：

操作系统：centos 5.6 x64

redis版本：redis-2.8.10.tar.gz

keepalived版本：keepalived-1.2.12.tar.gz

redis master : 192.168.101.50

redis salve : 192.168.101.51

原理：如果返回时间超过keepalived vrrp_scripts的超时时间,keepalived会进入faild 状态,从而触发keepalived集群开始进行vip漂移

当 Master 挂掉，Slave 正常时, Slave接管服务，有写权限，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，同时Slave等待Master同步数据完成之后，恢复Slave身份。

部署安装：

1、在master salve 上编译安装依赖包

yum -y install gcc gcc+ gcc-c++ openssl openssl-devel pcre pcre-devel

软件包download：

redis-2.8.10.tar.gz wget http://www.915c.com/softfile/redis-2.8.10.tar.gz

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

gperftools-2.1.tar.gz wget http://down.51cto.com/data/1332597

libunwind-1.1.tar.gz wget http://down.51cto.com/data/1332597

2、编译安装 (master salve 安装方法一致)

# tar xf libunwind-1.1.tar.gz

# cd libunwind-1.1

# CFLAGS=-fPIC ./configure
# make CFLAGS=-fPIC

# make CFLAGS=-fPIC install

# tar xf gperftools-2.1.tar.gz
# cd gperftools-2.1

# /configure --disable-cpu-profiler --disable-heap-profiler --disable-heap-checker --disable-debugalloc --enable-minimal

# make && make install

# echo "/usr/local/lib" > /etc/ld.so.conf.d/usr_local_lib.conf
# /sbin/ldconfig

# cd /usr/local/lib

# ln -sv libtcmalloc_minimal.so.4.1.2 libtcmalloc.so

# tar xf redis-2.8.10.tar.gz

# cd redis2.8.10

# mkdir -p /opt/redis

# make PREFIX=/opt/redis USE_TCMALLOC=yes FORCE_LIBC_MALLOC=yes install

3、配置redis

创建配置文件夹以及文件

mkdir -p /opt/redis/etc

mkdir -p /opt/redis/run
mkdir -p /opt/redis/data/6379
mkdir -p /opt/redis/log
cp /redis的解压路径 /redis.conf /opt/redis/etc/redis.conf
cp /opt/redis/etc/redis.conf /opt/redis/etc/redis_6379.conf
修改配置文件：
vim /opt/redis/etc/redis_6379.conf
daemonize yes
pidfile /opt/redis/run/redis_6379.pid
dir /opt/redis/data/6379
logfile /opt/redis/log/redis_6379.log
创建服务管理脚本
vim /etc/init.d/redis
#!/bin/sh
PATH="/opt/redis/bin:$PATH"
EXEC="/opt/redis/bin/redis-server"
CLIEXEC="/opt/redis/bin/redis-cli"
PIDFILE="/opt/redis/run/redis_6379.pid"
CONF="/opt/redis/etc/redis_6379.conf"
REDISPORT="6379"

case "$1" in
    start)
        if [ -f $$PIDFILE ]
        then
                echo "$PIDFILE exists, process is already running or crashed."
        else
                echo "Starting Redis server..."
                $EXEC $CONF
        fi
        ;;
    stop)
        if [ ! -f $PIDFILE ]
        then
                echo "$PIDFILE does not exist, process is not running."
        else
                PID=$(cat $PIDFILE)
                echo "Stopping ..."
                $CLIEXEC -p $REDISPORT shutdown
                while [ -x /proc/${PID} ]
                do
                    echo "Waiting for Redis to shutdown ..."
                    sleep 1
                done
                echo "Redis stopped."
        fi
        ;;
    *)
        echo "Usage: $0 {start|stop}" >&2
        exit 1
        ;;
esac

授权 chmod +x /etc/init.d/redis

vim /etc/sysctl.conf
在最后添加以下节点:

vm.overcommit_memory = 1

sysctl -p

redis 就安装完毕了

4、启动测试

启动redis 服务

# /etc/init.d/redis start

#ps -aux |grep redis 查看进程

打开防火墙6379端口

5、测试redis的主从复制

[root@master ~]# /opt/redis/bin/redis-cli -p 6379 set test1 www.baidu.com \\通过master set设置一个key键为test1 写入values值 www.baidu.com

返回一个ok

在master本地测试取test1 的key值

[root@master ~]# /opt/redis/bin/redis-cli -p 6379 get test1

在salve端测试读取master写入的文件test1

[root@slave ~]# /opt/redis/bin/redis-cli -p 6379 get test1

6、安装keepalived

# 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

7、首先在master上创建如下配置

# mkdir -p /etc/keepalived

# 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 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 {

192.168.101.52 ###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

}

在Redis Master上创建redis_master脚本

# 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 192.168.101.51(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

在Redis Master上创建redis_backup脚本

# 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 192.168.101.51(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 {

192.168.101.52 ###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

}

在Redis salve上创建redis_master脚本

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 192.168.101.50(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

在Redis Master上创建redis_backup脚本

# 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 192.168.101.50 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

# 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

8、测试高可用性。

1、启动master和slave节点上keepalived

[root@master ~]# /etc/init.d/keepalived start

启动 keepalived： [确定]

[root@slave ~]# /etc/init.d/keepalived start

Starting keepalived: [ OK ]

查看master 的网络地址 vip地址的绑定状态

查看slave

9、测试vip连接redis

[root@master ~]# /opt/redis/bin/redis-cli -h 192.168.101.52 INFO |grep -A8 Replication

[root@slave ~]# /opt/redis/bin/redis-cli -h 192.168.101.52 INFO |grep -A8 Replication

10、测试插入和取出key

$@_GN9D6P@2[V5XK_XT{83}7.jpg$

[root@slave ~]# /opt/redis/bin/redis-cli -h 192.168.101.52 set oneday www.baidu.com

You have new mail in /var/spool/mail/root

[root@slave ~]# /opt/redis/bin/redis-cli -h 192.168.101.52 get oneday

"www.baidu.com"

[root@slave ~]# /opt/redis/bin/redis-cli -h 192.168.101.50 get oneday

"www.baidu.com"

[root@slave ~]# /opt/redis/bin/redis-cli -h 192.168.101.51 get oneday

"www.baidu.com"

11、测试vip漂移和redis高可用

关闭master节点的redis服务

[root@master ~]# /etc/init.d/redis stop

Stopping ...

Redis stopped.

查看vip 地址 slave变化状态

master

slave

$ROZRC6P$NF5QQ2Q9R_GMN{J.jpg$

12、测试故障恢复redis master恢复

启动master节点的redis 服务器，观察变化情况

$_T$DZ6LI{V1CK5A`BV2`3[0.jpg$

slave节点

slave自动切换为slave节点服务

到此测试完成。

备注：

以上方案存在不足之处：1、当master节点故障后，虽然slave节点接管了服务，但是毕竟slave没有写入的权限，导致slave需要写入文件的时候报错

[root@slave ~]# /opt/redis/bin/redis-cli -h 192.168.101.52 set twoday www.sina.net

(error) READONLY You can‘t write against a read only slave.

这个时候，如果是强制将slave节点手打或者脚本升级为master节点，则出现当master恢复时，原master与slave已经隔离，不能完成数据同步。

2、通过哨兵Redis Sentinel 监控master slave 监听可以实现当master出故障时，slave可以自动切换为master并接管工作，但当master端恢复后，会一直停留在slave状态，不会再抢占成为master节点。

3、抛出一个问题：假如master 是一台服务器性能比较高，而slave是一台性能较差的服务器，如何做到，当master节点故障时，slave自动切换为master并且有读写的权限，当原master节点恢复后，自动抢占成为master节点？

本文出自 “my_soul” 博客，请务必保留此出处http://soul455879510.blog.51cto.com/6180012/1828558

redis+keepalived 主从热备实例

标签：redis+keepalived 高可用秒级切换

原文地址：http://soul455879510.blog.51cto.com/6180012/1828558

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redis+keepalived 主从热备 实例

redis+keepalived 主从热备实例