Cannot listen to partition changes if Topics without subscriptions

[fzj55]

Describe the bug

When the same consumer group subscribes to different topics, the leader cannot monitor the partition changes of another topic.

Kafka Version

• 2.8
• main branch

To Reproduce

The same consumer group consumerGroup
Start different instances. Some instances subscribe to topicA, and some instances subscribe to topicB. You can see the leader from the joingroup. Find the topic that the leader subscribes to. Assume it is topicA. Then modify the shards of topicB. You will find that the leader cannot trigger the joingroup.

Expected Behavior

The leader should start partitionWatcher on both topics

Observed Behavior

, but in fact only starts partitionWatcher on the topic which it subscribe.