CalvinConfluent commented on code in PR #18604: URL: https://github.com/apache/kafka/pull/18604#discussion_r1924240294
########## core/src/main/scala/kafka/log/UnifiedLog.scala: ########## @@ -600,6 +600,11 @@ class UnifiedLog(@volatile var logStartOffset: Long, */ def hasOngoingTransaction(producerId: Long, producerEpoch: Short): Boolean = lock synchronized { val entry = producerStateManager.activeProducers.get(producerId) + // With transactions V2, if we see a future epoch, we are likely in the process of completing the previous transaction. + // Return early with ConcurrentTransactionsException until the transaction completes. + if (entry != null && entry.currentTxnFirstOffset.isPresent && entry.producerEpoch() < producerEpoch) Review Comment: It reminds me of an optimation https://issues.apache.org/jira/browse/KAFKA-18042 Basically `entry.producerEpoch() > producerEpoch` is also illegal and can be rejected earlier instead of sending the add partition verification. I wonder if we can also throw an exception(ProducerFenced) here? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org