From e6965274558d82509eb181d96e8e009051bffd1a Mon Sep 17 00:00:00 2001
From: btlqql <2977859784@qq.com>
Date: Thu, 13 Aug 2026 13:58:55 +0800
Subject: [PATCH] [ISSUE #10894] Enforce Lite subscription quota for complete
 and batch updates

---
 .../broker/lite/LiteSubscriptionRegistryImpl.java    | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/broker/src/main/java/org/apache/rocketmq/broker/lite/LiteSubscriptionRegistryImpl.java b/broker/src/main/java/org/apache/rocketmq/broker/lite/LiteSubscriptionRegistryImpl.java
index b487b8757f4..119c5952b0c 100644
--- a/broker/src/main/java/org/apache/rocketmq/broker/lite/LiteSubscriptionRegistryImpl.java
+++ b/broker/src/main/java/org/apache/rocketmq/broker/lite/LiteSubscriptionRegistryImpl.java
@@ -97,6 +97,9 @@ public void addPartialSubscription(String clientId, String group, String topic,
             if (!liteLifecycleManager.isSubscriptionActive(topic, lmqName)) {
                 continue;
             }
+            if (!isLiteTopicSubscribed(clientGroup, lmqName) && getActiveSubscriptionNum() >= maxCount) {
+                throw new LiteQuotaException("lite subscription quota exceeded " + maxCount);
+            }
             thisSub.addLiteTopic(lmqName);
             // First remove the old subscription
             if (LiteMetadataUtil.isSubLiteExclusive(group, brokerController)) {
@@ -147,6 +150,10 @@ public void addCompleteSubscription(String clientId, String group, String topic,
             removeTopicGroup(clientGroup, lmqName, false);
         });
         lmqNameNew.forEach(lmqName -> {
+            long maxCount = brokerController.getBrokerConfig().getMaxLiteSubscriptionCount();
+            if (!isLiteTopicSubscribed(clientGroup, lmqName) && getActiveSubscriptionNum() >= maxCount) {
+                throw new LiteQuotaException("lite subscription quota exceeded " + maxCount);
+            }
             thisSub.addLiteTopic(lmqName);
             addTopicGroup(clientGroup, lmqName);
         });
@@ -269,6 +276,11 @@ public void cleanSubscription(String lmqName, boolean notifyClient) {
         }
     }
 
+    protected boolean isLiteTopicSubscribed(ClientGroup clientGroup, String lmqName) {
+        Set<ClientGroup> topicGroupSet = liteTopic2Group.get(lmqName);
+        return topicGroupSet != null && topicGroupSet.contains(clientGroup);
+    }
+
     protected void addTopicGroup(ClientGroup clientGroup, String lmqName) {
         Set<ClientGroup> topicGroupSet = liteTopic2Group
             .computeIfAbsent(lmqName, k -> ConcurrentHashMap.newKeySet());