ijuma commented on code in PR #12006: URL: https://github.com/apache/kafka/pull/12006#discussion_r850032346
########## clients/src/main/java/org/apache/kafka/clients/producer/internals/TransactionManager.java: ########## @@ -187,7 +187,7 @@ private void startSequencesAtBeginning(TopicPartition topicPartition, ProducerId private static final Comparator<ProducerBatch> PRODUCER_BATCH_COMPARATOR = (b1, b2) -> { if (b1.baseSequence() < b2.baseSequence()) return -1; else if (b1.baseSequence() > b2.baseSequence()) return 1; - else return b1.equals(b2) ? 0 : 1; + else return b1.equals(b2) ? 0 : Integer.compare(b1.hashCode(), b2.hashCode()); Review Comment: This is incorrect @artemlivshits, `Object.hashCode` is not based on object addresses in Java. The hashCode is 32 bits and object addresses can be 64-bits. Also, object addresses resulted in more collisions when used with hashmaps than the default implementation. I have seen collisions in practice that resulted in a huge amount of work to debug and diagnose. If you're interested, this was the fix https://github.com/squeryl/squeryl/commit/6e43673b273c270a39ba887ec9a07d921b566562 -- 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