[KAFKA-17017] AsyncConsumer#unsubscribe does not clean the assigned partitions

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.9.0
• Component/s: clients, consumer
• Labels: kip-848-client-support
• Assignee: PoAn Yang
• Reporter: Chia-Ping Tsai
• Created: 21/Jun/24 15:00
• Updated: 22/Jul/24 20:55
• Resolved: 16/Jul/24 20:18

Description

According to docs [0] `Consumer#unsubscribe` should clean both subscribed and assigned partitions. However, there are two issues about `AsyncConsumer`

1) if we don't set group id, `AsyncConsumer#unsubscribe`[1] will be no-op
2) if we set group id, `AsyncConsumer` is always in `UNSUBSCRIBED` state and so `MembershipManagerImpl#leaveGroup`[2] will be no-op

[0] https://github.com/apache/kafka/blob/trunk/clients/src/main/java/org/apache/kafka/clients/consumer/KafkaConsumer.java#L759
[1] https://github.com/apache/kafka/blob/trunk/clients/src/main/java/org/apache/kafka/clients/consumer/internals/AsyncKafkaConsumer.java#L1479
[2] https://github.com/apache/kafka/blob/trunk/clients/src/main/java/org/apache/kafka/clients/consumer/internals/MembershipManagerImpl.java#L666

Issue Links

• links to: GitHub Pull Request #16449