主：172.16.0.104
备：172.16.0.105
VIP：172.16.0.107
客户端直接连VIP，当master 104的redis挂掉后，105作为master。当104重启后，104作为105的slave。当105又挂掉之后，104作为master......
1、安装redis并配置主从同步
安装过程省略
1.1 配置104的redis实例：/etc/redis/redis.conf
requirepass 123456 #生产环境千万不要配置这么简单的密码
masterauth 123456 #备库密码，这里没有配置slaveof却配置masterauth是因为主备切换时需要用到密码
1.2 配置105的redis实例
requirepass 123456 #生产环境千万不要配置这么简单的密码
masterauth 123456 #主库密码
slaveof 172.16.0.104 6379
2、安装keepalived
安装过程省略
3、配置keepalived
Master（104）实例：
keepalived.conf
global_defs {
router_id test
}
vrrp_script chk_redis
{
script "/etc/keepalived/scripts/redis_check.sh 127.0.0.1 6379 123456"
interval 2
timeout 2
fall 3
}
vrrp_instance redis {
state BACKUP # 主也配置为SLAVE
interface eth0
virtual_router_id 51
priority 150
nopreempt # 不抢占，注意加上
advert_int 1
authentication {
auth_type PASS
auth_pass 123456
}
virtual_ipaddress {
172.16.0.107
}
track_script {
chk_redis
}
notify_master "/etc/keepalived/scripts/redis_master.sh 127.0.0.1 6379 123456"
notify_backup "/etc/keepalived/scripts/redis_backup.sh 127.0.0.1 6379 123456 172.16.0.105 6379"
notify_fault /etc/keepalived/scripts/redis_fault.sh
notify_stop /etc/keepalived/scripts/redis_stop.sh
}
redis_master.sh
#!/bin/bash
REDISCLI="redis-cli -h $1 -p $2 -a $3"
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_backup.sh
#!/bin/bash
REDISCLI="redis-cli -h $1 -p $2 -a $3"
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 $4 $5 >> $LOGFILE 2>&1
Slave（105）实例
keepalived.conf
global_defs {
router_id redis
}
vrrp_script chk_redis {
script "/etc/keepalived/scripts/redis_check.sh 127.0.0.1 6379 123456" ###监控脚本
interval 2 ###监控时间
timeout 2 ###超时时间
fall 3 ###重试次数
}
vrrp_instance redis {
state BACKUP ###设置为MASTER
interface eth0 ###监控网卡
virtual_router_id 51
priority 100 ###权重值
nopreempt # 不抢占，注意加上
advert_int 1
authentication {
auth_type PASS ###加密
auth_pass 123456 ###密码
}
track_script {
chk_redis ###执行上面定义的chk_redis
}
virtual_ipaddress {
172.16.0.107 ###VIP
}
notify_master "/etc/keepalived/scripts/redis_master.sh 127.0.0.1 6379 123456"
notify_backup "/etc/keepalived/scripts/redis_backup.sh 127.0.0.1 6379 123456 172.16.0.104 6379"
notify_fault /etc/keepalived/scripts/redis_fault.sh
notify_stop /etc/keepalived/scripts/redis_stop.sh
}
redis_master.sh
#!/bin/bash
REDISCLI="redis-cli -h $1 -p $2 -a $3"
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_backup.sh
#!/bin/bash
REDISCLI="redis-cli -h $1 -p $2 -a $3"
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 $4 $5 >> $LOGFILE 2>&1
公共配置
redis_check.sh
#!/bin/bash
ALIVE=`redis-cli -h $1 -p $2 -a $3 PING`
LOGFILE="/var/log/keepalived-redis-check.log"
echo "[CHECK]" >> $LOGFILE
date >> $LOGFILE
if [ $ALIVE == "PONG" ]; then :
echo "Success: redis-cli -h $1 -p $2 PING $ALIVE" >> $LOGFILE 2>&1
exit 0
else
echo "Failed:redis-cli -h $1 -p $2 PING $ALIVE " >> $LOGFILE 2>&1
exit 1
fi
redis_fault.sh
#!/bin/bash
LOGFILE=/var/log/keepalived-redis-state.log
echo "[fault]" >> $LOGFILE
date >> $LOGFILE
redis_stop.sh
#!/bin/bash
LOGFILE=/var/log/keepalived-redis-state.log
echo "[stop]" >> $LOGFILE
date >> $LOGFILE
启动keepalived：keepalived -D
查看ip漂移情况：ip a
配置要点：
双BACKUP + nopreempt，优先级大的先启动作为master，当master挂掉后，slave被选中成为新的master。
参考文章：http://www.cnblogs.com/lulu/archive/2013/04/14/3021261.html