From 65fbd737cc467d7677c076bccb267b30ffeacda4 Mon Sep 17 00:00:00 2001
From: liuhy <liuhongyu@apache.org>
Date: Mon, 3 Aug 2026 00:04:06 -0700
Subject: [PATCH 1/2] [ISSUE #10778] Skip empty priority queue groups

---
 .../service/route/MessageQueuePenalizer.java  | 14 +++++---
 .../route/MessageQueuePenalizerTest.java      | 34 +++++++++++++++++++
 2 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/proxy/src/main/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizer.java b/proxy/src/main/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizer.java
index d53056971dc..b26a51e2041 100644
--- a/proxy/src/main/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizer.java
+++ b/proxy/src/main/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizer.java
@@ -120,8 +120,11 @@ static <Q extends MessageQueue> Pair<Q, Integer> selectLeastPenaltyWithPriority(
         int bestPenalty = Integer.MAX_VALUE;
         for (List<Q> queues : queuesWithPriority) {
             Pair<Q, Integer> queueAndPenalty = selectLeastPenalty(queues, penalizers, startIndex);
-            int penalty =  queueAndPenalty.getRight();
-            if (queueAndPenalty.getRight() <= 0) {
+            if (queueAndPenalty == null) {
+                continue;
+            }
+            int penalty = queueAndPenalty.getRight();
+            if (penalty <= 0) {
                 return queueAndPenalty;
             }
             if (penalty < bestPenalty) {
@@ -129,6 +132,9 @@ static <Q extends MessageQueue> Pair<Q, Integer> selectLeastPenaltyWithPriority(
                 bestQueue = queueAndPenalty.getLeft();
             }
         }
-        return Pair.of(bestQueue,  bestPenalty);
+        if (bestQueue == null) {
+            return null;
+        }
+        return Pair.of(bestQueue, bestPenalty);
     }
-}
\ No newline at end of file
+}
diff --git a/proxy/src/test/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizerTest.java b/proxy/src/test/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizerTest.java
index f31d973cce5..1594b3f5aa7 100644
--- a/proxy/src/test/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizerTest.java
+++ b/proxy/src/test/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizerTest.java
@@ -282,6 +282,40 @@ public void testSelectLeastPenaltyWithPriority_EmptyQueues() {
         assertNull(result);
     }
 
+    /**
+     * Test selectLeastPenaltyWithPriority with only empty priority groups should return null
+     */
+    @Test
+    public void testSelectLeastPenaltyWithPriority_AllEmptyPriorityGroups() {
+        List<MessageQueuePenalizer<MessageQueue>> penalizers = Collections.singletonList(mq -> 10);
+        AtomicInteger startIndex = new AtomicInteger(0);
+        Pair<MessageQueue, Integer> result = MessageQueuePenalizer.selectLeastPenaltyWithPriority(
+            Arrays.asList(Collections.emptyList(), Collections.emptyList()), penalizers, startIndex);
+        assertNull(result);
+    }
+
+    /**
+     * Test selectLeastPenaltyWithPriority skips empty priority groups and selects from non-empty groups
+     */
+    @Test
+    public void testSelectLeastPenaltyWithPriority_SkipEmptyPriorityGroup() {
+        MessageQueue mq0 = new MessageQueue("topic", "broker", 0);
+        MessageQueue mq1 = new MessageQueue("topic", "broker", 1);
+        List<MessageQueue> queues = Arrays.asList(mq0, mq1);
+
+        List<MessageQueuePenalizer<MessageQueue>> penalizers = Collections.singletonList(
+            mq -> mq.getQueueId() == 0 ? 20 : 10
+        );
+
+        AtomicInteger startIndex = new AtomicInteger(0);
+        Pair<MessageQueue, Integer> result = MessageQueuePenalizer.selectLeastPenaltyWithPriority(
+            Arrays.asList(Collections.emptyList(), queues), penalizers, startIndex);
+
+        assertNotNull(result);
+        assertEquals(mq1, result.getLeft());
+        assertEquals(10, result.getRight().intValue());
+    }
+
     /**
      * Test selectLeastPenaltyWithPriority with single priority group delegates to selectLeastPenalty
      */

From 799a8aeb948ac669ed02e4d98a716b6a00858962 Mon Sep 17 00:00:00 2001
From: liuhy <liuhongyu@apache.org>
Date: Fri, 14 Aug 2026 06:25:46 -0700
Subject: [PATCH 2/2] docs(proxy): explain empty priority group result

---
 .../rocketmq/proxy/service/route/MessageQueuePenalizer.java      | 1 +
 1 file changed, 1 insertion(+)

diff --git a/proxy/src/main/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizer.java b/proxy/src/main/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizer.java
index b26a51e2041..2301c28e919 100644
--- a/proxy/src/main/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizer.java
+++ b/proxy/src/main/java/org/apache/rocketmq/proxy/service/route/MessageQueuePenalizer.java
@@ -133,6 +133,7 @@ static <Q extends MessageQueue> Pair<Q, Integer> selectLeastPenaltyWithPriority(
             }
         }
         if (bestQueue == null) {
+            // All priority groups were empty or absent.
             return null;
         }
         return Pair.of(bestQueue, bestPenalty);