lucasbru commented on code in PR #15511: URL: https://github.com/apache/kafka/pull/15511#discussion_r1522964906
########## clients/src/main/java/org/apache/kafka/clients/consumer/internals/MembershipManagerImpl.java: ########## @@ -508,9 +508,30 @@ private void processAssignmentReceived(ConsumerGroupHeartbeatResponseData.Assign */ private void replaceTargetAssignmentWithNewAssignment( ConsumerGroupHeartbeatResponseData.Assignment assignment) { - currentTargetAssignment.clear(); + + // Return if the same as current assignment; comparison without creating a new collection + if (currentTargetAssignment != null) { + // check if the new assignment is different from the current target assignment + if (currentTargetAssignment.partitions.size() == assignment.topicPartitions().size() && + assignment.topicPartitions().stream().allMatch( + tp -> currentTargetAssignment.partitions.containsKey(tp.topicId()) && + currentTargetAssignment.partitions.get(tp.topicId()).size() == tp.partitions().size() && + currentTargetAssignment.partitions.get(tp.topicId()).containsAll(tp.partitions()))) { + return; + } + } + + // Bump local epoch and replace assignment + long nextLocalEpoch; + if (currentTargetAssignment == null) { + nextLocalEpoch = 0; + } else { + nextLocalEpoch = currentTargetAssignment.localEpoch + 1; + } Review Comment: I think the server is bumping the target member epoch when any assignment for any member changes, while the local epoch is only bumped if the assignment for this specific member changes. So we should get fewer reconciliations. -- 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