Intro Redisson Sharded Topic

Intro Redisson Sharded Topic

這篇介紹Redisson Sharded Topic。

Intro

Java implementation of Redis based RShardedTopic object implements Sharded Publish / Subscribe mechanism.
It allows to subscribe on events published with multiple instances of RShardedTopic object with the same name.
Subscribe/publish operations are executed only on Redis node in Cluster which is bounded to specific topic name. 

Published messages via RShardedTopic aren't broadcasted across all Redis nodes as for RTopic object. 
Which reduces network bandwidth and Redis load.

Listeners are re-subscribed automatically after reconnection to Redis or Redis failover. 
All messages sent during absence of connection to Redis are lost. Use Reliable Topic for reliable delivery.

Code example

RShardedTopic topic = redisson.getShardedTopic("myTopic");
int listenerId = topic.addListener(SomeObject.class, new MessageListener<SomeObject>() {
    @Override
    public void onMessage(String channel, SomeObject message) {
        //...
    }
});

// in other thread or JVM
RShardedTopic topic = redisson.getShardedTopic("myTopic");
long clientsReceivedMessage = topic.publish(new SomeObject());