[KAFKA-14422] Consumer rebalance stuck after new static member joins a group with members not supporting static members

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.3.0, 2.4.0, 2.5.0, 2.6.0, 2.7.0, 2.8.0, 3.1.0, 3.0.0, 3.2.0, 3.3.0
• Fix Version/s: 3.4.0, 3.3.2, 3.2.4
• Assignee: David Jacot
• Reporter: David Jacot
• Created: 28/Nov/22 08:15
• Updated: 28/Nov/22 19:29
• Resolved: 28/Nov/22 19:29

Description

When a consumer group on a version prior to 2.3 is rolled upgraded to a newer version and static membership is enabled in the meantime, the consumer group remains stuck, iff the leader is still on the old version.

The issue is that setting `GroupInstanceId` in the response to the leader is only supported from JoinGroup version >= 5 and that `GroupInstanceId` is not ignorable nor handled anywhere else. Hence is there is at least one static member in the group, sending the JoinGroup response to the leader fails with a serialization error.

> org.apache.kafka.common.errors.UnsupportedVersionException: Attempted to write a non-default groupInstanceId at version 2

When this happens, the member stays around until the group coordinator is bounced because a member with a non-null `awaitingJoinCallback` is never expired.

We should do two things here:
1) `GroupInstanceId` should be ignorable;
2) We should handle errors while calling callbacks.

Issue Links

• links to: GitHub Pull Request #12909