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Boyang Chen commented on KAFKA-9679: ------------------------------------ Thanks for taking this up! [~sujayopensource] Yes, the behavior we want to fix is in MockConsumer.poll(). The addRecords fence adding a record into a non-existing partition, but wont' help if we add records to an existing partition, subscription changes and loses the partition, and mock consumer fail into illegal state due to unknown partition. I would recommend you to read this context: [https://github.com/apache/kafka/pull/8220/files#r389201119] to better understand the issue. Let me know if you have further questions. > Mock consumer should behave consistent with actual consumer > ----------------------------------------------------------- > > Key: KAFKA-9679 > URL: https://issues.apache.org/jira/browse/KAFKA-9679 > Project: Kafka > Issue Type: Test > Components: consumer, streams > Reporter: Boyang Chen > Assignee: Sujay Hegde > Priority: Major > Labels: help-wanted, newbie, newbie++ > > Right now in MockConsumer we shall return illegal state exception when the > buffered records are not able to find corresponding assigned partitions. This > is not the case for KafkaConsumer where we shall just not return those data > during `poll()` call. This inconsistent behavior should be fixed. > Note that if we are going to take this fix, the full unit tests need to be > executed to make sure no regression is introduced, as some tests are > potentially depending on the current MockConsumer behavior. -- This message was sent by Atlassian Jira (v8.3.4#803005)