[KAFKA-17228] Static member using new protocol should always replace the one using the old protocol

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.0
• Assignee: Dongnuo Lyu
• Reporter: Dongnuo Lyu
• Reviewer: David Jacot
• Created: 31/Jul/24 13:16
• Updated: 09/Aug/24 08:12
• Resolved: 09/Aug/24 08:12

Description

In the old protocol, when a static consumer shuts down, it won't send explicit LeaveGroup request. It's okay because the old protocol replaces the existing member whenever a new member with the same instance id joins.

However in the new protocol, we requires the existing member to send leave group for a new static member to replace the existing one. The gap causes the upgraded new consumer unable to join the group in both online/offline upgrade.

We should make the static member using new protocol replace the static member using old protocol regardless of whether the latter has left the group.

Issue Links

• links to: GitHub Pull Request #16800