[KAFKA-9653] Duplicate tasks on workers after rebalance

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 2.4.0, 2.3.2
• Component/s: connect
• Assignee: Konstantine Karantasis
• Reporter: Agam Brahma
• Created: 04/Mar/20 20:58
• Updated: 13/Jul/20 19:41
• Resolved: 11/Jun/20 03:20

Description

Verified the following

• observed issue goes away when `connect.protocol` is switched from `compatible` to `eager`
• Debug logs show `WorkerSourceTask` on two different nodes referencing the same task-id
• Debug logs show the node referring to the task as as part of both `Configured assignments` and `Lost assignments`

Issue Links

• is caused by: KAFKA-9849 Fix issue with worker.unsync.backoff.ms creating zombie workers when incremental cooperative rebalancing is used
• relates to: KAFKA-9184 Redundant task creation and periodic rebalances after zombie worker rejoins the group