lianetm commented on code in PR #16673: URL: https://github.com/apache/kafka/pull/16673#discussion_r1697100482
########## clients/src/main/java/org/apache/kafka/clients/consumer/internals/AsyncKafkaConsumer.java: ########## @@ -1443,12 +1443,7 @@ public void assign(Collection<TopicPartition> partitions) { // be no following rebalance. // // See the ApplicationEventProcessor.process() method that handles this event for more detail. - applicationEventHandler.add(new AssignmentChangeEvent(subscriptions.allConsumed(), time.milliseconds())); - - log.info("Assigned to partition(s): {}", partitions.stream().map(TopicPartition::toString).collect(Collectors.joining(", "))); - - if (subscriptions.assignFromUser(new HashSet<>(partitions))) - applicationEventHandler.add(new NewTopicsMetadataUpdateRequestEvent()); + applicationEventHandler.add(new AssignmentChangeEvent(time.milliseconds(), partitions)); Review Comment: Adding this only means that we will potentially return from the `assign()` without having really updated the subscription state. I wonder if we should go with the same approach we have on the unsubscribe [here](https://github.com/apache/kafka/blob/901c656a1da16c8473200c93e57991004fc1371d/clients/src/main/java/org/apache/kafka/clients/consumer/internals/AsyncKafkaConsumer.java#L1487-L1492), that needs to deal with a very similar situation (and actually, assign with empty triggers unsubscribe and goes down that path that seems more in-line with what the legacy does). The trick would be to add the assign event, but then poll for background events until the assign event completes (so we know that the subscription state was updated). Makes sense? -- 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