[KAFKA-13486] Kafka Connect: Failed to start task due to NPE

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 2.7.1
• Component/s: connect
• Environment: Kubernetes, custom docker image

Language

English Java

• Assignee: Unassigned
• Reporter: Geliba Uilte
• Created: 26/Nov/21 13:02
• Updated: 18/Oct/22 23:03
• Resolved: 18/Oct/22 23:03

Description

I have a Kafka Connect cluster with three workers running on Kubernetes. The workers communicate with each other using pod's IP (internal IP 192.X.X.X). Sometimes, pods are redistributed to different node. I am not sure if it has anything to do with the issue, but I think it makes pod's IP to be changed and Kafka Connect needs to rebalance.

Occasionally, tasks fail due to NPE.

From the connectors/:connector/status REST API, I can see this trace:

 

at org.apache.kafka.connect.runtime.Worker.startTask(Worker.java:517)
at org.apache.kafka.connect.runtime.distributed.DistributedHerder.startTask(DistributedHerder.java:1258)
at org.apache.kafka.connect.runtime.distributed.DistributedHerder.access$1700(DistributedHerder.java:127)
at org.apache.kafka.connect.runtime.distributed.DistributedHerder$10.call(DistributedHerder.java:1273)
at org.apache.kafka.connect.runtime.distributed.DistributedHerder$10.call(DistributedHerder.java:1269)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)

 

It looks like the issue is similar to KAFKA-10323 and

It seems NPE is thrown from here.

 

 

Issue Links

• duplicates: KAFKA-10323 NullPointerException during rebalance