Redis connection with Master Slave architecture.

[utkarsh19467]

Hi Sonu,

I have a redis master slave architecture. One of the server is master and other two are slave servers. All the servers have sentinel running in background for automatic failover.

Now I want my Spring Boot application to make connection with this architecture. If master fails, one of my slave will be promoted to master. Now my configuration should be something which starts adding data in new master.

Is there any configuration in your mind using which we can achieve this. I tried below configuration but faced issues like:

Cluster not enabled for this instance
Cluster not up -> if cluster is enabled.

https://www.fatalerrors.org/a/configuration-of-redis-sentinel-mode-and-its-application-in-springboot.html

Please let us know if you have something around this.

Thanks
Utkarsh

[sonus21]

Hi Utkarsh
Not sure, If I've followed you message.
Did you try RedisSentinelConfiguration along with LettuceConnectionFactory

[utkarsh19467]

Hi Sonu, I tried below configuration :

@bean
public LettuceConnectionFactory lettuceConnectionFactory() {
LettuceClientConfiguration clientConfig = LettuceClientConfiguration.builder()
.readFrom(ReadFrom.SLAVE_PREFERRED)
.build();
RedisSentinelConfiguration redisSentinelConfiguration = new RedisSentinelConfiguration();
redisSentinelConfiguration.master(masterName);
sentinelNodes.stream().forEach(sentinelNode -> {
String node[] = sentinelNode.split(":");
redisSentinelConfiguration.sentinel(node[0], Integer.valueOf(node[1]));
});
return new LettuceConnectionFactory(redisSentinelConfiguration, clientConfig);
}

And I am facing below error:

org.springframework.data.redis.RedisSystemException: Error in execution; nested exception is io.lettuce.core.RedisCommandExecutionException: ERR Error running script (call to f_f2bdba02a4ce0a64f658c13a9aa8e3b7135de184): @user_script:15: @user_script: 15: -READONLY You can't write against a read only replica.

Sorry for late reply as I was not available last week. Do you have any pointers on why I am facing this error. Please refer below configuration:

1 Master
2 Slaves

Sentinel running on all servers. If master fails, slave is promoted to master and request should start writing to new master instead of getting this error.

[sonus21]

#19

use MASTER_PREFERRED instead of SLAVE_PREFERRED

[utkarsh19467]

Ok Sonu. Thanks.