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

Reply via email to