[native]start multiple consumer in one process, or subscribe multiple topic in one consumer couldn't work.

[wongxinjie]

1. Please describe the issue you observed:

   • What did you do (The steps to reproduce)?
     I create a consumer using Aliyun RocketMQ service, if I just subscribe one topic in one consumer or start one consumer in one process, it works normally. But when it comes to subscribe multiple topics in one consumer or start multiple consumers in one process, it just prints the starting log and hangs.

   • What did you expect to see?
     Subscribe multiple topics could work normally.

   • What did you see instead?

2. Please tell us about your environment:

   • What is your OS?
     ubuntu 18.04

   • What is your client version?
     native

   • What is your RocketMQ version?
     lastest

[ShannonDing]

link #242

[wongxinjie]

link #242

nope, I try but the PR didn't fix the bug.

[wolftankk]

link #242

nope, I try but the PR didn't fix the bug.

In the RocketMQ admin consumer page, u try to find where this group is in? and detail log for it.

ps:
#194 (comment)

you can try it, maybe slove.

[xujianhai666]

strange, I run native version online, everything is okay. could u write an example for us? thx a lot @wongxinjie

[wenfengwang]

I reproduce the situation and found many unexpected cases of below

Subscribe 2 topics in a consumer

Case 1: nothing received, maybe hang
Case 2: received only one topic messages, another can't receive
Case 3: all received.

Start 2 consumers in a process

Case 4: one consumer received and another not
Case 5: one consumer received and another not, and broker response to Code: 24

Case 6: all can't receive messages

[wenfengwang]

I reproduce the situation and found many unexpected cases of below

Subscribe 2 topics in a consumer

Case 1: nothing received, maybe hang
Case 2: received only one topic messages, another can't receive
Case 3: all received.

Start 2 consumers in a process

Case 4: one consumer received and another not
Case 5: one consumer received and another not, and broker response to Code: 24

Case 6: all can't receive messages

I will try to fix these

[wenfengwang]

fixed at: #310

[wenfengwang]

@wongxinjie In RocketMQ, it is not allowed that create multiple consumers have the same consumerGroup in one client Instance. If you want to create multiple consumers have the same consumerGroup in one process, you should make sure for unique ClientID by calling WithInstance when create consumer instance.

After fixing, it may work well that subscribe multiple topics in one consumer and create multiple consumers that have different consumerGroup in one client instance, welcome have a test :)