注意：请确保已经安装Redis和keepalived，本文不在介绍如何安装。
1、使用版本说明
Redis版本：5.0.2
Keepalived版本：1.3.5
Linux 版本：Centos7.9
查看Redis版本：
/usr/local/redis/bin/redis-cli -v
查看Keepalived版本信息：
rpm -qa|grep keepalived 或者 keepalived -v
2、功能实现说明：
- 使用Keepalived提供虚拟IP对外访问Redis
- Redis搭建主从数据同步，主用来读写数据 、从主要进行主数据同步备份。
- 当主出现宕机，Keepalived虚拟IP自动指向从服务器。从服务器临时变为主服务器继续工作。
- 待主服务器重新启动后，Keepalived虚拟IP重新指向主服务器。主服务器同步从服务器数据后继续工作。从服务器由临时主变为从继续进行主数据同步备份。
3、说明图
Keepalived会生成一个虚拟IP。客户端需要访问虚拟IP进行Redis连接:
3.1 、主和备服务器运行中
3.2、主宕机，备服务器运行中
3.3、 主恢复，备服务器运行中
4、搭建Redis主从
首先确保两台服务器都安装了Redis服务，Redis的端口号和密码两台服务器必须保持一致。我这里两台服务器都是使用端口号：6379和密码：1234qwer
服务器IP：
主服务器：192.168.42.130
备服务器：192.168.42.133
4.1、 修改配置文件
首先需要修改备服务器redis配置文件，把备服务器redis挂载到主服务器redis下面实现主从配置。
进入redis目录
cd /usr/local/redis/
修改redis.conf文件
vim redis.conf
找到replicaof和masterauth属性进行配置
# replicaof <masterip> <masterport>
replicaof 192.168.42.130 6379
# If the master is password protected (using the "requirepass" configuration
# directive below) it is possible to tell the replica to authenticate before
# starting the replication synchronization process, otherwise the master will
# refuse the replica request.
#
# masterauth <master-password>
masterauth "1234qwer"replicaof：主服务器IP和端口号
masterauth：用于在进行主从复制时,保护Redis主节点的数据安全。密码就是设置相同的主从节点的密码。以确保只有经过授权的从节点才能够连接到主节点。如果不配置，会导致节点连接失败：master_link_status:down
通过登录redis输入：info replication 可以查看Redis集群配置信息。如果搭建成功，会显示节点信息。
注意： 在Redis 5.0及以上版本，SLAVEOF 命令已经被废弃，并且在服务器上使用该命令会导致命令失效。所以在Redis 5.0及以上版本，设置复制的正确方法是使用 REPLICAOF 命令。为了兼容旧版本，通过配置的方式仍然支持 slaveof，但是通过命令的方式则不行了。
4.2、验证主从复制功能
验证方式：登录主服务器Redis，插入一条key数据。在备服务器中登录Redis进行通过该key进行查询，查看是否获取到数据。如果数据获取成功，说明Redis主从复制搭建成功。
进入主服务器登录redis
/usr/local/redis/bin/redis-cli
进行密码认证
auth 1234qwer
输出OK，表示认证成功。存入数据
set verify-key "Test Verify is Success"
输出OK，表示插入成功。接下来登录备服务器查看数据。进入备服务器登录redis：
/usr/local/redis/bin/redis-cli
进行密码认证
auth 1234qwer
输出OK，表示认证成功。获取key数据
get verify-key
输出："Test Verify is Success"，说明Redis主从搭建成功。
5、配置Keepalived信息
/etc/keepalived目录中存放keepalived.conf文件。在该目录下创建scripts_redis文件夹，目录 /etc/keepalived/scripts_redis，将 redis_stop.sh 、redis_master.sh、redis_fault.sh 、redis_check.sh 、redis_backup.sh 放入scripts_redis文件目录下。
5.1 主服务器配置
编写keepalived.conf
! Configuration File for keepalivedglobal_defs {router_id redis-master #唯一标识 注意主备服务名不可相同script_user rootenable_script_security
}vrrp_script redis_check { #脚本检测名称,下方调用必须和这个名称一致script "/etc/keepalived/scripts_redis/redis_check.sh" #监听redis是否启动脚本路径interval 4 #监听心跳weight -5fall 3rise 2
}vrrp_instance VI_redis {state MASTER #当前keepalived状态 MASTER 或者 BACKUPinterface eth0 #网卡名称根据实际情况设置可通过命令ifconfig查看virtual_router_id 21priority 110 #权重 主服务要高于备服务garp_master_refresh 10garp_master_refresh_repeat 2advert_int 1nopreemptunicast_src_ip 192.168.42.130 #单播模式 当前服务器主服务器IP地址unicast_peer {192.168.42.133 #备服务器Ip}authentication { #keepalived之间通信的认证账号、密码auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.42.161 #虚拟IP地址 客户端统一的访问地址}garp_master_delay 1garp_master_refresh 5track_interface {eth0 #网卡}track_script {redis_check #脚本检测调用名称}notify_master /etc/keepalived/scripts_redis/redis_master.sh #master脚本 keepalived设置的状态为master时触发或者master停止后，backup升级为master时触发notify_backup /etc/keepalived/scripts_redis/redis_backup.sh #backup脚本 keepalived设置的状态为backup时触发notify_fault /etc/keepalived/scripts_redis/redis_fault.sh #fault脚本notify_stop /etc/keepalived/scripts_redis/redis_stop.sh #stop脚本 keepalived停止时触发}
编写 redis_master.sh，当主脚本启动时，需要先同步备服务器redis数据后，在设置为主节点进行启动：
#!/bin/bashLOGFILE=/var/log/keepalived-redis-status.log
REDISCLI="/usr/local/redis/bin/redis-cli"echo "Running redis_master.sh..." >>$LOGFILE
echo "[Master]" >> $LOGFILE
date >> $LOGFILE
echo "Being Master..." >> $LOGFILE
echo "Running SLAVEOF cmd..." >> $LOGFILE
$REDISCLI -h 192.168.42.130 -p 6379 -a 1234qwer CONFIG SET masterauth "1234qwer" 2>&1
$REDISCLI -h 192.168.42.130 -p 6379 -a 1234qwer REPLICAOF 192.168.42.133 6379 2>&1sleep 5secho "Run slaveof no one cmd..." >>$LOGFILE$REDISCLI -h 192.168.42.130 -p 6379 -a 1234qwer REPLICAOF NO ONE >>$LOGFILE 2>&1echo "Finished running redis_master.sh..." >>$LOGFILE
编写redis_backup.sh，
#!/bin/bashLOGFILE=/var/log/keepalived-redis-status.log
REDISCLI="/usr/local/redis/bin/redis-cli"
echo "Running redis_bakcup.sh..." >>$LOGFILE
echo "[Backup]" >> $LOGFILE
date >> $LOGFILE
echo "Being Slave..." >> $LOGFILE
echo "Run SLAVEOF cmd..." >> $LOGFILE
$REDISCLI -h 192.168.42.130 -p 6379 -a 1234qwer CONFIG SET masterauth "1234qwer" >>$LOGFILE 2>&1
$REDISCLI -h 192.168.42.130 -p 6379 -a 1234qwer REPLICAOF 192.168.42.133 6379 >>$LOGFILE 2>&1
echo "Finished running redis_backup.sh..." >>$LOGFILE5.2、备服务器配置
编写keepalived.conf
! Configuration File for keepalivedglobal_defs {router_id redis-slave #唯一标识 注意主备服务名不可相同script_user rootenable_script_security
}vrrp_script redis_check {script "/etc/keepalived/scripts_redis/redis_check.sh" #监听redis是否启动脚本路径interval 4 #监听心跳weight -5fall 3 rise 2
}vrrp_instance VI_redis {state BACKUP #当前keepalived状态 设置为BACKUPinterface eth0virtual_router_id 21priority 100garp_master_refresh 10garp_master_refresh_repeat 2advert_int 1nopreemptunicast_src_ip 192.168.42.133 #单播模式 当前服务器IP地址unicast_peer {192.168.42.130 #主服务器Ip}authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.42.161 #虚拟IP地址 客户端统一的访问地址}garp_master_delay 1garp_master_refresh 5track_interface {eth0}track_script {redis_check}notify_master /etc/keepalived/scripts_redis/redis_master.shnotify_backup /etc/keepalived/scripts_redis/redis_backup.shnotify_fault /etc/keepalived/scripts_redis/redis_fault.sh notify_stop /etc/keepalived/scripts_redis/redis_stop.sh
}编写redis_master.sh
#!/bin/bash
# LOGFILE文件需要跟据实际情况更改
LOGFILE=/var/log/keepalived-redis-status.log
REDISCLI="/usr/local/redis/src/redis-cli"echo "Running redis_master.sh..." >>$LOGFILE
echo "[Master]" >> $LOGFILE
date >> $LOGFILE
echo "Begin Master ..." >> $LOGFILE
echo "Run slaveof no one cmd...">>$LOGFILE
# SLAVEOF 5.0以上已经弃用 REPLICAOF
$REDISCLI -h 192.168.42.133 -p 6379 -a 1234qwer REPLICAOF NO ONE >>$LOGFILE 2>&1
echo "Finished running redis_master.sh..." >>$LOGFILE
编写redis_backup.sh
#!/bin/bashLOGFILE=/var/log/keepalived-redis-status.log
REDISCLI="/usr/local/redis/src/redis-cli"echo "Running redis_bakcup.sh..." >>$LOGFILE
echo "[Backup]" >> $LOGFILE
date >> $LOGFILE
echo "Being Slave..." >> $LOGFILE
sleep 15s #休眠15秒，确保主服务器脚本redis_master.sh执行完毕后在执行主从命令
echo "Run SLAVEOF cmd..." >> $LOGFILE
# SLAVEOF 5.0已经弃用 改为：REPLICAOF
$REDISCLI -h 192.168.42.133 -p 6379 -a 1234qwer CONFIG SET masterauth "1234qwer" >>$LOGFILE 2>&1
$REDISCLI -h 192.168.42.133 -p 6379 -a 1234qwer REPLICAOF 192.168.42.130 6379 >>$LOGFILE 2>&1
echo "Finished running redis_backup.sh..." >>$LOGFILE
5.3、编写验证Redis是否启动脚本
编写redis_check.sh脚本,通过监听端口号判断（主备一致）
#!/bin/bash
LOGFILE=/var/log/check-redis-status.log
echo "Running redis_check.sh..." >> $LOGFILE
date >> $LOGFILE
CHECK=$(ss -tnlp|grep 6379)
if [ $? -ne 0 ]; thenecho "redis-server is not running..." >> $LOGFILEsystemctl stop keepalived.serviceexit 1
elseecho "redis-server is running..." >> $LOGFILEexit 0
fi
echo "Finished running redis_check.sh..." >> $LOGFILE
5.4 其他脚本
编写 redis_fault.sh （主备一致）
#!/bin/bashLOGFILE=/var/log/keepalived-redis-status.log
echo "Running redis_fault.sh..." >>$LOGFILE
echo "[Fault]" >> $LOGFILE
date >> $LOGFILE
echo "Finished running redis_fault.sh..." >> $LOGFILE编写 redis_stop.sh （主备一致）
#!/bin/bash
LOGFILE=/var/log/keepalived-redis-status.log
echo "Running redis_stop.sh...." >>$LOGFILE
echo "[Stop]" >> $LOGFILE
date >> $LOGFILE
echo "Finished running redis_stop.sh...." >>$LOGFILE
5.5、给脚本授可执行权限
chmod +x /etc/keepalived/scripts_redis/*.sh
5.6、 keepalived相关命令
Keepalived 安装命令
yum install keepalived -y
Keepalived配置所在目录
/etc/keepalived
Keepalived 日志文件
/var/log/message
启动Keepalived命令
systemctl start keepalived.service
重启Keepalived命令
systemctl restart keepalived.service
查看Keepalived状态命令
systemctl status keepalived.service
查看Keepalived虚拟VIP ip
ip addr
关闭Keepalived命令
systemctl stop keepalived.service
6、验证主备双活
我们可以通过连接工具RedisDesktopManager进行测试主备双活。首先连接地址填写keepalived生成的虚拟IP地址：192.168.42.161、 输入端口号：6379和密码：1234qwer
连接成功后，插入一条数据进行数据测试。之后在把主服务器redis停止模拟服务器宕机，测试连接继续进行数据插入。然后在把主服务器redis启动，keepalived也需要启动。启动完成后查看数据是否一致。如果一致说明主备双活搭建成功。
