[KAFKA-16294] Add group protocol migration enabling config

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.8.0
• Assignee: Dongnuo Lyu
• Reporter: Dongnuo Lyu
• Created: 21/Feb/24 21:13
• Updated: 10/Apr/24 17:59
• Resolved: 10/Apr/24 17:59

Description

The online upgrade is triggered when a consumer group heartbeat request is received in a classic group. The downgrade is triggered when any old protocol request is received in a consumer group. We only accept upgrade/downgrade if the corresponding group migration config policy is enabled.

This is the first part of the implementation of online group protocol migration, adding the kafka config group protocol migration. The config has four valid values – both(both upgrade and downgrade are allowed), upgrade(only upgrade is allowed), downgrade(only downgrade is allowed) and none(neither is allowed.).

At present the default value is NONE. When we start enabling the migration, we expect to set BOTH to default so that it's easier to roll back to the old protocol as a quick fix for anything wrong in the new protocol; when using consumer groups becomes default and the migration is near finished, we will set the default policy to UPGRADE to prevent unwanted downgrade causing too frequent migration. DOWNGRADE could be useful for revert or debug purposes.

Issue Links

• links to: GitHub Pull Request #15411