I. deployment environment
System: centos7
The deployment of the master-slave cluster is completed by starting two different redis instances on the Linux system
yum source deployed

II. Download and install redis
1. Download: download on official website
2, installation
Create the / app / directory and install redis in the / app / directory

[root@liyg ~]# mkdir /app
[root@liyg ~]# cd /usr/local/src/
[root@liyg src]# ls
redis-4.0.11.tar.gz
[root@liyg src]# tar zxf redis-4.0.11.tar.gz -C /app/
[root@liyg~]# yum install -y gcc*
[root@liyg ~]# cd /app/redis-4.0.11/
[root@liyg redis-4.0.11]# make
[root@liyg redis-4.0.11]# make install

3,Start different instances by configuring different ports

[root@liyg ~]# mkdir /app/redis_replication
[root@liyg ~]# mkdir /app/redis_replication/7001_master
[root@liyg ~]# mkdir /app/redis_replication/7002_slave
[root@liyg ~]# cp /app/redis-4.0.11/redis.conf /app/redis_replication/7001_master/
[root@liyg ~]# cp /app/redis-4.0.11/redis.conf /app/redis_replication/7002_slave/

Edit master profile

[root@liyg ~]# cd /app/redis_replication/
[root@liyg redis_replication]# vim 7001_master/redis.conf
    #Change port 6379 to 7001
    dir /app/redis_replication/7001_master
    pidfile /var/run/redis_7001.pid
    logfile "/app/redis_replication/7001_master/7001.log"
    protected-mode no   ##yes to no to turn off security mode
    daemonize yes    ##Start as a Daemons
    requirepass qwer1234   ##Turn on password authentication
    masterauth qwer1234    ##When the sentinel mode is turned on, it needs to be added to avoid that the slave cannot be synchronized when upgrading to master

Edit the slave profile

[root@liyg redis_replication]# vim 7001_master/redis.conf
    #Port changed to 7002
    dir /app/redis_replication/7002_slave
    pidfile /var/run/redis_7002.pid
    logfile "/app/redis_replication/7002_slave/7002.log"
    protected-mode no
    masterauth qwer1234   ##Password required to synchronize master
    requirepass qwer1234   ##Turn on password authentication
    slaveof 127.0.0.1 7001  ##Newly added

Start redis

[root@liyg redis_replication]# redis-server 7001_master/redis.conf 
2521:C 03 Dec 15:50:54.660 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
2521:C 03 Dec 15:50:54.661 # Redis version=4.0.11, bits=64, commit=00000000, modified=0, pid=2521, just started
2521:C 03 Dec 15:50:54.661 # Configuration loaded
[root@liyg redis_replication]# redis-server 7002_slave/redis.conf 
2530:C 03 Dec 15:51:07.037 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
2530:C 03 Dec 15:51:07.037 # Redis version=4.0.11, bits=64, commit=00000000, modified=0, pid=2530, just started
2530:C 03 Dec 15:51:07.037 # Configuration loaded

4, validation

[root@liyg redis_replication]# redis-cli -p 7001 -a qwer1234 info replication
role:master
connected_slaves:1
slave0:ip=127.0.0.1,port=7002,state=online,offset=70,lag=1

[root@liyg redis_replication]# redis-cli -p 7002 -a qwer1234 info replication
master_host:127.0.0.1
master_port:7001
...

Create a KEY in the master to check whether the slave is synchronized

[root@liyg ~]# redis-cli -p 7001 -a qwer1234 set k1 t1
OK
[root@liyg ~]# redis-cli -p 7002 -a qwer1234 get k1
"t1"

At this point, the redis master-slave configuration is complete

III. configure the redis master-slave sentinel mode

[root@liyg app]# cp redis-4.0.11/sentinel.conf redis_replication/
[root@liyg app]# vim redis_replication/sentinel.conf 

protected-mode no  ##Turn off safe mode
sentinel monitor mymaster 127.0.0.1 7002 1 
sentinel auth-pass mymaster qwer1234 ##Enable when the redis master-slave cluster has password verification

start-up

 [root@liyg app]# redis-sentinel redis_replication/sentinel.conf 

Verification

Close the master 7001 port and check whether the 7002 port is upgraded to master through sentry

[root@liyg redis_replication]# redis-cli -p 7001 -a qwer1234 shutdown

When the master is off, you can see the output of the sentry

...
2138:X 04 Dec 09:59:15.625 # +failover-end master mymaster 127.0.0.1 7001
2138:X 04 Dec 09:59:15.625 # +switch-master mymaster 127.0.0.1 7001 127.0.0.1 7002
2138:X 04 Dec 09:59:15.625 * +slave slave 127.0.0.1:7001 127.0.0.1 7001 @ mymaster 127.0.0.1 7002
2138:X 04 Dec 09:59:18.645 # +sdown slave 127.0.0.1:7001 127.0.0.1 7001 @ mymaster 127.0.0.1 7002

[root@liyg redis_replication]# redis-cli -p 7002 -a qwer1234 info replication

role:master
connected_slaves:0

You can see that the original slave7002 has been upgraded to master and the 7001 instance has been started again

[root@liyg redis_replication]# redis-server 7001_master/redis.conf 

[root@liyg redis_replication]# redis-cli -p 7001 -a qwer1234 info replication

role:slave
master_host:127.0.0.1
master_port:7002

7001 has become a slave of 7002, so far, the verification is successful