rocketmq | Apache RocketMQ is a cloud native messaging | Pub Sub library

Now I have to make this app a container and deploy it in k8s deployment with 3 replica. But these pods will all get same data and send to the same rocketmq topic.

There is no request. My app connect to a server and it will send data to app by TCP. Every Pod will connect to that server.

If you want to do this with more than one instance, they need to coordinate in some way.

Leader Election pattern is a way to run multiple instances, but only one can be active (e.g. when you read from the same queue). This is a pattern to coordinate - only one instance is active at the time. So this pattern only use your replicas for higher availability.

If you want that all your replicas actively work, this can be done with techniques like sharding or partitioning. This is also how e.g. Kafka (e.g. similar to a queue) makes concurrent work from queues.

There are other ways to solve this problem as well, e.g. to implement some form of locks to coordinate - but partitioning or sharding as in Kafka is probably the most "cloud native" solution.

I am afraid that you are wrong.

RocketMQ does not support ttl which means the message will NOT be deleted controlled by a client parameter, though the message will be indeed deleted after a period of time(for example 7 days).

So if you need to implement a ttl like consuming, you should do it in your consumer like: