[KAFKA-9540] Application getting "Could not find the standby task 0_4 while closing it" error

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.4.0, 2.5.0
• Fix Version/s: 2.4.1, 2.6.0, 2.5.1
• Component/s: streams
• Assignee: A. Sophie Blee-Goldman
• Reporter: Badai Aqrandista
• Created: 11/Feb/20 22:13
• Updated: 15/Apr/20 21:15
• Resolved: 18/Feb/20 18:13

Description

Because of this the following line, there is a possibility that some standby tasks might not be created:

https://github.com/apache/kafka/blob/2.4.0/streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamThread.java#L436

Then causing this line to not adding the task to standby task list:

https://github.com/apache/kafka/blob/2.4.0/streams/src/main/java/org/apache/kafka/streams/processor/internals/StreamThread.java#L299

But this line assumes that all standby tasks are to be created and add it to the standby list:

https://github.com/apache/kafka/blob/2.4.0/streams/src/main/java/org/apache/kafka/streams/processor/internals/TaskManager.java#L168

This results in user getting this error message on the next PARTITION_ASSIGNMENT state:

Could not find the standby task 0_4 while closing it (org.apache.kafka.streams.processor.internals.AssignedStandbyTasks:74)

But the harm caused by this issue is minimal: No standby task for some partitions. And it is recreated on the next rebalance anyway. So, I suggest lowering this message to WARN. Or probably check to WARN when standby task could not be created.

Issue Links

• links to: GitHub Pull Request #8092