lianetm commented on code in PR #20055: URL: https://github.com/apache/kafka/pull/20055#discussion_r2186107711
########## group-coordinator/src/main/java/org/apache/kafka/coordinator/group/modern/consumer/CurrentAssignmentBuilder.java: ########## @@ -317,4 +451,29 @@ private ConsumerGroupMember computeNextAssignment( .build(); } } + + /** + * Gets the set of topic IDs that the member is subscribed to. + * + * @return The set of topic IDs that the member is subscribed to. + */ + private Set<Uuid> subscribedTopicIds() { + Set<String> subscriptions = member.subscribedTopicNames(); + String subscribedTopicRegex = member.subscribedTopicRegex(); + if (subscribedTopicRegex != null && !subscribedTopicRegex.isEmpty()) { + ResolvedRegularExpression resolvedRegularExpression = resolvedRegularExpressions.get(subscribedTopicRegex); + if (resolvedRegularExpression != null) { + if (subscriptions.isEmpty()) { + subscriptions = resolvedRegularExpression.topics; + } else if (!resolvedRegularExpression.topics.isEmpty()) { + subscriptions = new UnionSet<>(subscriptions, resolvedRegularExpression.topics); + } + } else { + // Treat an unresolved regex as matching no topics, to be conservative. + } + } + + TopicIds subscribedTopicIds = new TopicIds(subscriptions, metadataImage.topics()); + return subscribedTopicIds; Review Comment: ```suggestion return new TopicIds(subscriptions, metadataImage.topics()); ``` ########## group-coordinator/src/main/java/org/apache/kafka/coordinator/group/GroupMetadataManager.java: ########## @@ -2243,21 +2243,30 @@ private CoordinatorResult<ConsumerGroupHeartbeatResponseData, CoordinatorRecord> // epoch 0 and that it is fully initialized. boolean bumpGroupEpoch = group.groupEpoch() == 0; - bumpGroupEpoch |= hasMemberSubscriptionChanged( + boolean subscribedTopicNamesChanged = hasMemberSubscriptionChanged( groupId, member, updatedMember, records ); - - bumpGroupEpoch |= maybeUpdateRegularExpressions( + UpdateRegularExpressionsResult updateRegularExpressionsResult = maybeUpdateRegularExpressions( context, group, member, updatedMember, records ); + // The subscription has changed when either the subscribed topic names or subscribed topic + // regex has changed. + boolean hasSubscriptionChanged = subscribedTopicNamesChanged || updateRegularExpressionsResult.subscribedTopicRegexChanged; Review Comment: nit: this seems only needed further down on `maybeReconcile` , should we move it closer? ########## group-coordinator/src/main/java/org/apache/kafka/coordinator/group/modern/consumer/CurrentAssignmentBuilder.java: ########## @@ -215,6 +284,64 @@ private boolean ownsRevokedPartitions( return false; } + /** + * Updates the current assignment, removing any partitions that are not part of the subscribed topics. + * This method is a lot faster than running the full reconciliation logic in computeNextAssignment. + * + * @param memberAssignedPartitions The assigned partitions of the member to use. + * @return A new ConsumerGroupMember. + */ + private ConsumerGroupMember updateCurrentAssignment( + Map<Uuid, Set<Integer>> memberAssignedPartitions + ) { + Set<Uuid> subscribedTopicIds = subscribedTopicIds(); + + // Reuse the original map if no topics need to be removed. + Map<Uuid, Set<Integer>> newAssignedPartitions = memberAssignedPartitions; + Map<Uuid, Set<Integer>> newPartitionsPendingRevocation = new HashMap<>(member.partitionsPendingRevocation()); + for (Map.Entry<Uuid, Set<Integer>> entry : memberAssignedPartitions.entrySet()) { Review Comment: I guess it would be common for regex case to end up with empty `subscribedTopicIds` here (regex not resolved), but still we would iterate the whole set of assigned partitions. Would it make sense to treat that case separately to avoid iterating to remove 1 by 1 if subscribedTopicIds.isEmpty? -- 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