[KAFKA-15554] Update client state machine to align with protocol sending one assignment at a time

• Type: Sub-task
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 3.7.0
• Component/s: clients, consumer
• Labels: kip-848 kip-848-client-support kip-848-e2e kip-848-preview
• Assignee: Lianet Magrans
• Reporter: Lianet Magrans
• Created: 05/Oct/23 20:10
• Updated: 19/Dec/23 03:15
• Resolved: 18/Oct/23 15:10

Description

The new consumer group protocol will be sending one assignment to the member, and wait for an ack or timeout before sending any other assignment. 

The client state machine will be updated so that it takes on new target assignment only if there is no other in process. If a new target assignment is received in this case, the member should fail with a fatal error, as this is not expected in the protocol. 

Issue Links

• is part of: KAFKA-14246 Update threading model for Consumer
• links to: GitHub Pull Request #14413