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redis主从配置及通过keepalived实现redis自动切换,redis主从实现10秒检查与恢复

2014-07-07 14:51 881 查看
一:环境介绍:Master: 192.168.1.4Slave: 192.168.1.5Virtural IP Address (VIP): 192.168.1.253
二:设计思路: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。
三:安装配置前准备工作
1.在主服务器192.168.1.4上面做下面操作echo "192.168.1.4 test01" >> /etc/hosts
echo "192.168.1.5 test" >> /etc/hosts
2.在从服务器192.168.1.5上面做下面操作
echo "192.168.1.4 test01" >> /etc/hosts
echo "192.168.1.5 test" >> /etc/hosts

四:主服务器配置redis
1.下载安装redis软件包

wget http://download.redis.io/releases/redis-2.8.12.tar.gztar xf redis-2.8.12.tar.gz
cd redis-2.8.12
make && make install
cd src/
cp redis-server redis-cli redis-benchmark redis-check-aof redis-check-dump /usr/local/bin
cd /usr/local/bin
ls -ll
然后将源码中的 redis.conf 复制到 /etc/redis.conf
cp /root/redis-2.8.12/redis.conf /etc/redis.conf
修改 /etc/redis.conf里面可以把  daemonize no 修改为daemonize yes
就可以默认在后台执行redis-server了。

再制作一个 init.d 的启动脚本:
vim /etc/init.d/redis-server
#!/usr/bin/env bash
#
# redis start up the redis server daemon
#
# chkconfig: 345 99 99
# description: redis service in /etc/init.d/redis \
#             chkconfig --add redis or chkconfig --list redis \
#             service redis start  or  service redis stop
# processname: redis-server
# config: /etc/redis.conf

PATH=/usr/local/bin:/sbin:/usr/bin:/bin

REDISPORT=6379
EXEC=/usr/local/bin/redis-server
REDIS_CLI=/usr/local/bin/redis-cli

PIDFILE=/var/run/redis.pid
CONF="/etc/redis.conf"
#make sure some dir exist
if [ ! -d /var/lib/redis ] ;then
mkdir -p /var/lib/redis
mkdir -p /var/log/redis
fi

case "$1" in
status)
ps -A|grep redis
;;
start)
if [ -f $PIDFILE ]
then
echo "$PIDFILE exists, process is already running or crashed"
else
echo "Starting Redis server..."
$EXEC $CONF
fi
if [ "$?"="0" ]
then
echo "Redis is running..."
fi
;;
stop)
if [ ! -f $PIDFILE ]
then
echo "$PIDFILE does not exist, process is not running"
else
PID=$(cat $PIDFILE)
echo "Stopping ..."
$REDIS_CLI -p $REDISPORT SHUTDOWN
while [ -x ${PIDFILE} ]
do
echo "Waiting for Redis to shutdown ..."
sleep 1
done
echo "Redis stopped"
fi
;;
restart|force-reload)
${0} stop
${0} start
;;
*)
echo "Usage: /etc/init.d/redis {start|stop|restart|force-reload}" >&2
exit 1
esac
chmod o+x /etc/init.d/redis-serverchkconfig --add redis-serverservice redis-server start
五:从发服务器配置redis从服务器,配置一样,只不过 修改/etc/redis.conf 中 slaveof <masterip> <masterport>修改为slaveof 192.168.1.4 6379然后开启从服务器的redis服务。start redis-server start

六:进行redis主从测试#主服务器redis-cli -p 6379 set hello world#从服务器redis-cli -p 6379 get hello"world"
#主服务器redis-cli -p 6379 set hello world2#从服务器redis-cli -p 6379 get hello"world2"redis-cli -p 6379 set hello world(error) READONLY You can't write against a read only slave.成功配置主从redis服务器,由于配置中有一条从服务器是只读的,所以从服务器没法设置数据,只可以读取数据。

七:安装和配置keepalived
1.在Master和Slave上安装Keepalived
$ yum install keepalived -y2.默认安装完成keepalived之后是没有配置文件的,因此我们需要手动创建:首先,在Master上创建如下配置文件:$ vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

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 eth1                ###监控网卡
virtual_router_id 51
priority 100            ###权重值
authentication {
auth_type PASS        ###加密
auth_pass 1111        ###密码
}

track_script {
chk_redis             ###执行上面定义的chk_redis
}

virtual_ipaddress {
192.168.1.253         ######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
}
3.然后,在Slave上创建如下配置文件:
$ vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

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 eth1       ###监控网卡
virtual_router_id 51
priority 10          ###比MASTRE权重值低
authentication {
auth_type PASS
auth_pass 1111        ###密码与MASTRE相同
}

track_script {
chk_redis        ###执行上面定义的chk_redis
}

virtual_ipaddress {
192.168.1.253   ####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

}
4.在Master和Slave上创建监控Redis的脚本
$ mkdir /etc/keepalived/scripts$ vim /etc/keepalived/scripts/redis_check.sh
#!/bin/bash
ALIVE=`/usr/local/bin/redis-cli PING`
if [ "$ALIVE" == "PONG" ]; then
echo $ALIVE
exit 0
else
echo $ALIVE
exit 1
fi
5.编写以下负责运作的关键脚本:
notify_master /etc/keepalived/scripts/redis_master.shnotify_backup /etc/keepalived/scripts/redis_backup.shnotify_fault /etc/keepalived/scripts/redis_fault.shnotify_stop /etc/keepalived/scripts/redis_stop.sh 因为Keepalived在转换状态时会依照状态来呼叫:当进入Master状态时会呼叫notify_master当进入Backup状态时会呼叫notify_backup当发现异常情况时进入Fault状态呼叫notify_fault当Keepalived程序终止时则呼叫notify_stop1)首先,在Redis Master上创建notity_master与notify_backup脚本:
$ vim /etc/keepalived/scripts/redis_master.sh
#!/bin/bash
REDISCLI="/usr/local/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 192.168.1.5 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="/usr/local/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 192.168.1.5 6379 >> $LOGFILE  2>&1
2)在Redis Slave上创建notity_master与notify_backup脚本:
$ vim /etc/keepalived/scripts/redis_master.sh
#!/bin/bash
REDISCLI="/usr/local/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 192.168.1.4 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="/usr/local/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 192.168.1.4 6379 >> $LOGFILE  2>&1
3)然后在Master与Slave创建如下相同的脚本:
$ 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
6.在主从服务器上面给脚本都加上可执行权限:
$ chmod +x /etc/keepalived/scripts/*.sh7.进行相关功能测试

启动Master和slave上的Redis$ /etc/init.d/redis start启动Master和slave上的Keepalived$ /etc/init.d/keepalived start
尝试通过VIP连接Redis:$ redis-cli -h 192.168.0.253 INFO连接成功,Slave也连接上来了。role:masterslave0:192.168.1.5,6379,online尝试插入一些数据:
$ redis-cli -h 192.168.0.253 SET Hello RedisOK
从VIP读取数据$ redis-cli -h 192.168.0.253 GET Hello"Redis"从Master读取数据$ redis-cli -h 192.168.0.1 GET Hello"Redis"从Slave读取数据$ redis-cli -h 192.168.0.2 GET Hello"Redis"8.通过模拟相关故障,进行功能测试
将Master上的Redis进程杀死:$ killall -9 redis-server查看Master上的Keepalived日志$ tail -f /var/log/keepalived-redis-state.log[fault]Thu Sep 27 08:29:01 CST 2012
同时Slave上的日志显示:$ tail -f /var/log/keepalived-redis-state.log[master]
2014年 07月 07日 星期一 16:42:52 CST
Being master....
Run SLAVEOF cmd ...
OK Already connected to specified master
Run SLAVEOF NO ONE cmd ...
OK
然后我们可以发现,Slave已经接管服务,并且担任Master的角色了。$ redis-cli -h 192.168.1.253 INFO$ redis-cli -h 192.168.1.5 INFOrole:master

然后我们恢复Master的Redis进程$ /etc/init.d/redis start查看Master上的Keepalived日志$ tail -f /var/log/keepalived-redis-state.log[master]
2014年 07月 07日 星期一 16:48:08 CST
Being master....
Run SLAVEOF cmd ...
OK
Run SLAVEOF NO ONE cmd ...
OK
同时Slave上的日志显示:$ tail -f /var/log/keepalived-redis-state.log[backup]Fri Sep 28 14:16:37 CST 2012Being slave....Run SLAVEOF cmd ...OK发现目前的Master已经再次恢复了Master的角色,故障切换以及自动恢复都成功了。
参考:/article/3738168.html
/article/4245893.html
/article/4245892.html
Saltstack 利用pillar实现redis多实例部署
/article/4422412.html

redis主从实现10秒检查与恢复
redis主从架构
问题:redis down重启后,能恢复key值,时间会有延迟,down机之间的值将会丢失。实验环境,主从做在一台服务器上,利用不同端口。解决方案:redis主从至今还不算完善,我们利用redis主从主要做redis备份,master宕机后,实现10s内尽可能的恢复key值,主主要做读写,实现快速读写,不做任何备份方式,从就简单实用rdb方式实现备份。思路原理:redis有两种持久化方式,rdb 与aof模式,考虑到aof模式增长过快,恢复比较缓慢,就在从上做rdb模式,主down之后,脚本检查主的状态,之后在从上做bgsave,把从上的rdb文件copy到主的data目录里,重新启动主。通过判断主上key值得数量,是否跟从上的数量一样,来判断是否恢复正常,然后就可以实现key值得完全恢复。备份方式为,一个小时copy一次从上的rbd文件,做一个小时一次的备份。
脚本的思路 主要实现上述思路原理,脚本有点别扭,2做了主,1做的redis从。
#!/bin/bash

DATE=`date +%Y%m%d%M%s`
REDIS_DIR=/usr/local/redis
REDIS2_DIR=/usr/local/redis2
BIN_DIR=/usr/local/redis/bin
DATA1_DIR=/usr/local/redis/data
DATA2_DIR=/usr/local/redis2/data
PORT1=6378
PORT2=6379

function BACKUP_RDB {
ps -ef |grep $PORT2 >/dev/null
if  [ $? -eq 0 ];then
${BIN_DIR}/redis-cli -p $PORT2 bgsave >/dev/null
if [ $? -eq 0 ];then
echo -e "\033[31m MASTER REDIS DOWN AND SLAVE bgsave DONE\033[0m"
${BIN_DIR}/redis-cli -p $PORT2 SLAVEOF NO ONE >/dev/null
fi
fi
}

function CP_RDB {
[ -d ${DATA1_DIR}/redisbackup ]  || mkdir ${DATA1_DIR}/redisbackup
if [ -f $DATA2_DIR/dump.rdb ];then
mv ${DATA1_DIR}/dump.rdb  ${DATA1_DIR}/redisbackup/dump.rdb.$DATE
cp ${DATA2_DIR}/dump.rdb  ${DATA1_DIR}/
fi
}

function  START_REDIS {
KEY2_NUM=`${BIN_DIR}/redis-cli -p $PORT2 INFO  |grep db[0-9]*.key |awk -F[:=,] '{total+=$3}END{print total}'`
${BIN_DIR}/redis-server ${REDIS_DIR}/etc/redis.conf
netstat -tnlp |grep "$PORT1" >/dev/null
a=$?
if [ $a -ne 0 ];then
while [ $a -ne 0 ];do
sleep 2
netstat -tnlp | grep "127.0.0.1:$PORT1" 1>/dev/null 2>/dev/null
a=$?
done
echo -e "\033[32m MASTER REDIS RUNNING ........\033[0m"
sleep 7
KEY1_NUM=`${BIN_DIR}/redis-cli -p $PORT1  INFO  |grep db[0-9]*.key |awk -F[:=,] '{total+=$3}END{print

total}'`
#        echo ${KEY1_NUM}
if [ $KEY1_NUM -ge $KEY2_NUM ];then
${BIN_DIR}/redis-cli -p $PORT2 SLAVEOF 127.0.0.1 $PORT1 >/dev/null
echo -e "\033[32m MASTER AND SLAVE are Normal sync \033[0m"
else
echo -e "\033[31m KEY NUM are not equal, MASTER AND SLAVE are not Normal sync,place to check ! \033[0m"
break
fi
else
echo -e "\033[32m MASTER REDIS RUNNING ........\033[0m"
sleep 7
KEY1_NUM=`${BIN_DIR}/redis-cli -p $PORT1 INFO  |grep db[0-9]*.key |awk -F[:=,] '{total+=$3}END{print total}'`
#        echo ${KEY1_NUM}
if [ $KEY1_NUM -ge $KEY2_NUM ];then
${BIN_DIR}/redis-cli -p $PORT2 SLAVEOF 127.0.0.1 $PORT1 >/dev/null
echo -e "\033[32m MASTER AND SLAVE are Normal sync \033[0m"
else
echo -e "\033[31m KEY NUM are not equal, MASTER AND SLAVE are not Normal sync,place to check ! \033[0m"
break
fi
fi
}

while true;do
sleep 10
netstat -tnlp | grep "127.0.0.1:$PORT1" 1>/dev/null 2>/dev/null
TRAP1=$?
ps -ef |grep "$PORT1" >/dev/null
TRAP2=$?
if [ $TRAP1 -ne  0 ] || [ $TRAP2 -ne  0 ];then
#echo redis-master down
BACKUP_RDB
CP_RDB
START_REDIS
fi
done

在恢复的过程中,比较主的key和主宕机后从的key,来判断是否恢复正常,遇到的问题:在恢复过程中,主key的值一直小于从的key的值,但是主启动完全正常,key值也完全一样,经过思考发现,是程序执行问题,脚本执行太快,当执行到比较的时候,key值得数量未完全恢复,只是时间的问题,所以执行了sleep 3 秒之后,一切正常。大家要根据自己key值得数量的大小来决定判断sleep的时间。本文出自 “从心开始” 博客,请务必保留此出处http://hao360.blog.51cto.com/5820068/1435297
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