[KAFKA-10792] Source tasks can block herder thread by hanging during stop

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.0, 2.5.0, 2.4.1, 2.6.0, 2.4.2, 2.5.1, 2.7.0
• Fix Version/s: 2.5.2, 2.8.0, 2.7.1, 2.6.2
• Component/s: connect
• Assignee: Chris Egerton
• Reporter: Chris Egerton
• Created: 01/Dec/20 19:53
• Updated: 14/Jun/23 16:06
• Resolved: 04/Dec/20 22:53

Description

If a source task blocks during its stop method, the herder thread will also block, which can cause issues with detecting rebalances, reconfiguring connectors, and other vital functions of a Connect worker.

This occurs because the call to SourceTask::stop occurs on the herder's thread, instead of on the source task's own dedicated thread. This can be fixed by moving the call to SourceTask::stop onto the source task's dedicated thread and aligning with the current approach for Connector instances and SinkTask instances.

Issue Links

• causes: KAFKA-15090 Source tasks are no longer stopped on a separate thread
• is duplicated by: KAFKA-12726 misbehaving Task.stop() can prevent other Tasks from stopping
• is related to: KAFKA-14670 Refactor connect plugins to be called from wrapper classes
• relates to: KAFKA-6566 SourceTask#stop() not called after exception raised in poll()
• links to: GitHub Pull Request #9669
• links to: GitHub Pull Request #9880