redis 主从配置，自动切换

标签：redis keepalived

基础信息

• 软件版本：
  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：
  • 安装目录：/usr/local/redis
  • 数据目录：/data4/redisdata
  • 配置文件：/usr/local/redis/redis.conf

• Keepalived配置：

  • 安装目录：/usr/local/keepalived
  • 配置文件：/etc/keepalived/keepalived.conf
• 脚本软件包：http://down.51cto.com/data/2444547
  • master 脚本压缩包放在master主机，slave脚本压缩包放在slave主机。

初始环境配置(master和slave上都进行操作)

1. 关闭防火墙，SeLinux,配置yum源。

2. 安装必要的软件：

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

3. 安装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. 安装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主从配置

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

   bind 0.0.0.0
   daemonize yes
   dir /data4/redisdata

   slave 上修改相同的信息，并添加slaveof的配置：

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

2. master和slave上为redis配置单独用户并启动服务

   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 主备配置

1. 在master节点修改/etc/keepalived/keepalived.conf为如下配置：

   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节点修改/etc/keepalived/keepalived.conf配置文件内容为如下配置：

   
   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. 添加主备keepalived状态脚本文件
   • 上传脚本压缩包到/etc/keepalived/目录下，解压到scripts目录，并添加脚本执行权限。
   • 创建日志记录目录：

     mkdir /var/log/keepalived/

4. 启动keepalived

   先启动主节点keepalved,再启动slave节点

   systemctl start keepalived

5. 查看keepalived和redis工作状态

   • 主节点上查看有vip,从节点上无vip

   ip a|grep gl

   • 主redis为master状态，从节点为slave状态

     redis-cli  info replication

6. 测试redis+keepalived主从是否正常

   • 分别依次关闭master上的redis和keepalived，查看主从状态和vip飘移情况。
   • 查看master和slave上的各项日志情况：

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

   故障处理

   当redis-master出现问题停机或者应用终止后，需要对进行故障排查，正确的恢复启动顺序如下：

   1. 使用redisuser 启动masrer,并与当前的slave(此时已经切换为master)进行数据同步：

    su - redisuser 
    cd /usr/local/redis
    ./bin/redis-server ./redis.conf  #启动redis
    netstat -lntp
    sh /etc/keepalived/scripts/redis_backup.sh # 使用脚本同步redis
    redis-cli  info replication  #查看同步状态

   2. 同步完成之后切换为root,启动keepalived，此时由于是不抢占模式，VIP仍然在slave上。

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

   3. 重启备用节点的keepalived,脚本自动完成主备切换

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

redis 主从配置，自动切换

标签：redis keepalived

原文地址：http://blog.51cto.com/tryingstuff/2093119