基礎信息

• 軟件版本：
  CentOS7.2.1511 Keepalived v1.3.4 Redis3.2.4
• IP信息：
  • master: 192.168.56.11
  • slave: 192.168.56.12
  • vip: 192.168.56.100
• Redis配置：
  • 安裝目錄：/usr/local/redis
  • 數據目錄：/data4/redisdata
  • 配置文件：/usr/local/redis/redis.conf

• Keepalived配置：

  • 安裝目錄：/usr/local/keepalived
  • 配置文件：/etc/keepalived/keepalived.conf
• 腳本軟件包：http://down.51cto.com/data/2444547
  • master 腳本壓縮包放在master主機，slave腳本壓縮包放在slave主機。

初始環境配置(master和slave上都進行操作)

1. 關閉防火墻，SeLinux,配置yum源。

2. 安裝必要的軟件：

   yum -y install gcc gcc+ openssl openssl-devel  tcl wget -y

3. 安裝redis

   
   cd /home
   wget http://download.redis.io/releases/redis-3.2.4.tar.gz
   tar -xf ./redis-3.2.4.tar.gz
   mv redis-3.2.4 /usr/local/
   cd /usr/local/redis-3.2.4/deps/
   make hiredis lua jemalloc linenoise
   cd ..
   make test
   make 
   make install
   mkdir -p /usr/local/redis/bin
   mkdir -p /data4/redisdata
   cd /usr/local/redis-3.2.4/src
   cp redis-benchmark redis-check-aof redis-cli redis-server mkreleasehdr.sh /usr/local/redis/bin/
   cd /usr/local/redis-3.2.4
   cp redis.conf /usr/local/redis/
   cp /usr/local/bin/redis-cli  /usr/bin/
    
   

4. 安裝keepalived

   cd /home
   wget http://www.keepalived.org/software/keepalived-1.3.4.tar.gz
   tar xf keepalived-1.3.4.tar.gz 
   cd keepalived-1.3.4
   ./configure 
   make
   make install

Redis主從配置

1. 在master上修改配置文件/usr/local/redis/redis.conf參數

   bind 0.0.0.0
   daemonize yes
   dir /data4/redisdata

   slave 上修改相同的信息，並添加slaveof的配置：

   bind 0.0.0.0
   daemonize yes
   dir /data4/redisdata
   slaveof 192.168.56.11 6379
    
   

2. master和slave上為redis配置單獨用戶並啟動服務

   useradd redisuser
   passwd redisuser
   chown -R redisuser:redisuser /usr/local/redis/redis.conf
   chown -R redisuser:redisuser /usr/local/redis/bin/redis-server
   chown redisuser /data4/redisdata
   su - redisuser
   cd /usr/local/redis
   ./bin/redis-server ./redis.conf

3. Redis口令信息：

   username: redisuser
   password: redi13%&

Keepalived 主備配置

1. 在master節點修改/etc/keepalived/keepalived.conf為如下配置：

   global_defs {
      lvs_id LVS_redis
   }
   vrrp_script chk_redis { 
       script "/etc/keepalived/scripts/redis_check.sh"
       weight -20
       interval 2                                     
   } 
   
   vrrp_instance VI_1 { 
       state backup                            
       interface eth0                          
       virtual_router_id 51
       nopreempt
       priority 200      
       advert_int 5                      
       track_script { 
           chk_redis                     
       } 
       virtual_ipaddress { 
            192.168.56.100
       }
       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 
   }

2. Keepalived 的Backup節點修改/etc/keepalived/keepalived.conf配置文件內容為如下配置：

   
   global_defs {
     lvs_id LVS_redis
   }
   
   vrrp_script chk_redis { 
       script "/etc/keepalived/scripts/redis_check.sh"   
       weight  -20 
       interval 2                                       
   } 
   vrrp_instance VI_1 { 
       state backup                                
       interface eth0                              
       virtual_router_id 51 
       priority 190    
       advert_int  5                            
       track_script { 
            chk_redis                   
       } 
       virtual_ipaddress { 
            192.168.56.100                    
       } 
       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. 添加主備keepalived狀態腳本文件
   • 上傳腳本壓縮包到/etc/keepalived/目錄下，解壓到scripts目錄，並添加腳本執行權限。
   • 創建日誌記錄目錄：

     mkdir /var/log/keepalived/

4. 啟動keepalived

   先啟動主節點keepalved,再啟動slave節點

   systemctl start keepalived

5. 查看keepalived和redis工作狀態

   • 主節點上查看有vip,從節點上無vip

   ip a|grep gl

   • 主redis為master狀態，從節點為slave狀態

     redis-cli  info replication

6. 測試redis+keepalived主從是否正常

   • 分別依次關閉master上的redis和keepalived，查看主從狀態和vip飄移情況。
   • 查看master和slave上的各項日誌情況：

   tail -f /var/log/keepalived/redis-state.log 
   tail -f /var/log/messages

   故障處理

   當redis-master出現問題停機或者應用終止後，需要對進行故障排查，正確的恢復啟動順序如下：

   1. 使用redisuser 啟動masrer,並與當前的slave(此時已經切換為master)進行數據同步：

    su - redisuser 
    cd /usr/local/redis
    ./bin/redis-server ./redis.conf  #啟動redis
    netstat -lntp
    sh /etc/keepalived/scripts/redis_backup.sh # 使用腳本同步redis
    redis-cli  info replication  #查看同步狀態

   2. 同步完成之後切換為root,啟動keepalived，此時由於是不搶占模式，VIP仍然在slave上。

   [root@ost-redis1 ~]# systemctl start keepalived
   [root@ost-redis1 ~]# redis-cli  INFO replication

   3. 重啟備用節點的keepalived,腳本自動完成主備切換

   [root@ost-redis2 ~]# systemctl restart keepalived
   [root@ost-redis2 ~]# redis-cli  INFO replication

redis 主從配置，自動切換