redis keepalive+redis 主從高可用

1 准備

1.1 准備
keepalived-2.0.18.tar.gz
redis-5.0.4.tar.gz
1.2 說明
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接管服務升級Master，有寫權限，同時關閉主從復制功能；
當 Master 恢復正常, Master降級為Slave同步數據，開啟主從復制。

1.3 測試服務器信息

Master redis: 192.168.56.103

Slave redis: 192.168.56.104

2. 配置redis 服務

1. 解壓縮

tar zxf redis-5.0.4.tar.gz
mv redis-5.0.4 /soft/server
cd /soft/server
mv redis-5.0.4 redis

2. 編譯安裝 

cd /soft/server/redis
make && make install

3. redis配置文件修改

vim redis.conf
...
bind 0.0.0.0   # 修改支持網絡訪問
protected-mode no   # 同樣一個安全配置，默認yes是不能網絡訪問的
daemonize yes   # 后台運行redis
slaveof 192.168.56.103 6379   # 指定Master IP，同步（僅從配置）

4. 配置redis服務啟動腳本

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
# 注意不同位置要修改變量
PATH=/usr/local/bin:/sbin:/usr/bin:/bin
REDISPORT=6379
EXEC=/paic/rd6379/bin/redis-server
REDIS_CLI=/paic/rd6379/redis-cli
 
PIDFILE=/var/run/redis.pid
CONF="/soft/server/redis/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

5. 配置開機自啟

chkconfig --add redis-server
chkconfig redis-server on

配置keepalive服務

1. 編譯安裝

tar zxf keepalived-1.2.22.tar.gz
cd keepalived-1.2.22
./configure --prefix=/usr/local/keepalived
make && make install

2. 配置文件設置

# 拷貝keepalived服務
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/keepalived
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/keepalived

# 配置keepalived服務
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/keepalived
mkdir /etc/keepalived

# 拷貝配置文件
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/

3. keepalive配置文件

Master節點

! Configuration File for keepalived
vrrp_script chk_redis {
 
    script "/root/scripts/redis_check.sh"    ###監控腳本 
    interval 2                         ###監控時間
    }
 
#網卡需要注意，使用ifconfig查看一下當前活動網卡
 
vrrp_instance VI_1 {
    state BACKUP                ###設置為BACKUP
    nopreempt                   # 不搶占MASTER
    interface eth0                ###監控網卡   
    virtual_router_id 51
    priority 100            ###權重值 
    authentication {
        auth_type PASS        ###加密 
        auth_pass 1q2w3e        ###密碼
    }
    #設置額外的監控，里面的任意一個網卡出現問題，都會進入FAULT狀態
    track_interface {
       eth0
    }
    track_script {
         chk_redis            ###執行上面定義的chk_redis 
    }
    virtual_ipaddress {
       192.168.0.99        ######VIP
    }
        notify_master /root/scripts/redis_master.sh
        notify_backup /root/scripts/redis_backup.sh
        notify_fault  /root/scripts/redis_fault.sh
        notify_stop  /root/scripts/redis_stop.sh
 
}

Slave節點

! Configuration File for keepalived
 
vrrp_script chk_redis {
    script "/root/scripts/redis_check.sh"    ###監控腳本 
    interval 2                  ###監控時間
    }
 
 #同樣要注意網卡
 
vrrp_instance VI_1 {
    state BACKUP        ###設置為BACKUP 
    interface eth0      ###監控網卡
    virtual_router_id 51
    priority 10          ###比MASTRE權重值低 
    authentication {
        auth_type PASS
        auth_pass 1q2w3e        ###密碼與MASTRE相同 
    }
    #設置額外的監控，里面的任意一個網卡出現問題，都會進入FAULT狀態
    track_interface {
       eth0
    }
    track_script {
    chk_redis        ###執行上面定義的chk_redis 
    }
    virtual_ipaddress {
        192.168.0.99 ####vip
    }
        notify_master /root/scripts/redis_master.sh
        notify_backup /root/scripts/redis_backup.sh
        notify_fault  /root/scripts/redis_fault.sh
        notify_stop  /root/scripts/redis_stop.sh
}

4. keepalive腳本

# Keepalive 定義的四種狀態腳本說明
當進入Master狀態時會呼叫notify_master
當進入Backup狀態時會呼叫notify_backup
當發現異常情況時進入Fault狀態呼叫notify_fault
當Keepalived程序終止時則呼叫notify_stop

 

redis_check.sh 檢測redis是否正常腳本，正常則返回PONG，返回代碼0，否則返回代碼1

#!/bin/bash 

ALIVE=`/usr/local/bin/redis-cli PING`
if [ "$ALIVE" == "PONG" ]; then
  echo $ALIVE 
  exit 0
else
  echo $ALIVE 
  exit 1
fi

 

redis_master.sh 我被選入Master時，執行的腳本

#!/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 NO ONE cmd ..." >> $LOGFILE
$REDISCLI SLAVEOF NO ONE >> $LOGFILE 2>&1

 

redis_fault.sh 當檢測服務不正常是，執行fault腳本

#!/bin/bash 

LOGFILE=/var/log/keepalived-redis-state.log
echo "[fault]" >> $LOGFILE
date >> $LOGFILE

 

redis_stop.sh keepalive終止時寫入日志

#!/bin/bash 
LOGFILE=/var/log/keepalived-redis-state.log
echo "[stop]" >> $LOGFILE
date >> $LOGFILE

 

redis_backup.sh 進入slave時執行的腳本

#!/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

echo "Run SLAVEOF cmd ..." >> $LOGFILE
$REDISCLI SLAVEOF 192.168.0.4 6379 >> $LOGFILE  2>&1  # IP為指定主redis的IP

這里backup 腳本主要說明一下，我的keepalive配置了不去搶占Master，也就是當我Master 宕機后，我master再次起來就是slave，這時就是執行redis_backup的時候了，我去指定我的Master去同步

5. 配置開機自啟

chkconfig --add keepalived
chkconfig keepalived on