(rocketmq) branch develop updated: [ISSUE #10644] Add LMQ number gauge metric to Broker observability (#10645)

[lizhimin]

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lizhimins pushed a commit to branch develop
in repository https://gitbox.apache.org/repos/asf/rocketmq.git


The following commit(s) were added to refs/heads/develop by this push:
     new 577b89f2cd [ISSUE #10644] Add LMQ number gauge metric to Broker 
observability (#10645)
577b89f2cd is described below

commit 577b89f2cdddf0d42cfd3c1b6effdac0cd0e467c
Author: Quan <zsjper...@foxmail.com>
AuthorDate: Wed Jul 22 11:43:58 2026 +0800

    [ISSUE #10644] Add LMQ number gauge metric to Broker observability (#10645)
    
    - Add GAUGE_LMQ_NUM constant in BrokerMetricsConstant
    - Register ObservableLongGauge in BrokerMetricsManager reading from 
messageStore.getQueueStore().getLmqNum()
    - Expose rocketmq_lmq_number metric for monitoring LMQ resource usage
---
 .../apache/rocketmq/broker/metrics/BrokerMetricsConstant.java    | 1 +
 .../org/apache/rocketmq/broker/metrics/BrokerMetricsManager.java | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git 
a/broker/src/main/java/org/apache/rocketmq/broker/metrics/BrokerMetricsConstant.java
 
b/broker/src/main/java/org/apache/rocketmq/broker/metrics/BrokerMetricsConstant.java
index e87ce9ad02..d39416e4e6 100644
--- 
a/broker/src/main/java/org/apache/rocketmq/broker/metrics/BrokerMetricsConstant.java
+++ 
b/broker/src/main/java/org/apache/rocketmq/broker/metrics/BrokerMetricsConstant.java
@@ -25,6 +25,7 @@ public class BrokerMetricsConstant {
     public static final String GAUGE_BROKER_PERMISSION = 
"rocketmq_broker_permission";
     public static final String GAUGE_TOPIC_NUM = "rocketmq_topic_number";
     public static final String GAUGE_CONSUMER_GROUP_NUM = 
"rocketmq_consumer_group_number";
+    public static final String GAUGE_LMQ_NUM = "rocketmq_lmq_number";
 
     public static final String COUNTER_MESSAGES_IN_TOTAL = 
"rocketmq_messages_in_total";
     public static final String COUNTER_MESSAGES_OUT_TOTAL = 
"rocketmq_messages_out_total";
diff --git 
a/broker/src/main/java/org/apache/rocketmq/broker/metrics/BrokerMetricsManager.java
 
b/broker/src/main/java/org/apache/rocketmq/broker/metrics/BrokerMetricsManager.java
index eda80dfd44..299b712b37 100644
--- 
a/broker/src/main/java/org/apache/rocketmq/broker/metrics/BrokerMetricsManager.java
+++ 
b/broker/src/main/java/org/apache/rocketmq/broker/metrics/BrokerMetricsManager.java
@@ -93,6 +93,7 @@ import static 
org.apache.rocketmq.broker.metrics.BrokerMetricsConstant.GAUGE_CON
 import static 
org.apache.rocketmq.broker.metrics.BrokerMetricsConstant.GAUGE_CONSUMER_QUEUEING_LATENCY;
 import static 
org.apache.rocketmq.broker.metrics.BrokerMetricsConstant.GAUGE_CONSUMER_READY_MESSAGES;
 import static 
org.apache.rocketmq.broker.metrics.BrokerMetricsConstant.GAUGE_HALF_MESSAGES;
+import static 
org.apache.rocketmq.broker.metrics.BrokerMetricsConstant.GAUGE_LMQ_NUM;
 import static 
org.apache.rocketmq.broker.metrics.BrokerMetricsConstant.GAUGE_PROCESSOR_WATERMARK;
 import static 
org.apache.rocketmq.broker.metrics.BrokerMetricsConstant.GAUGE_PRODUCER_CONNECTIONS;
 import static 
org.apache.rocketmq.broker.metrics.BrokerMetricsConstant.HISTOGRAM_FINISH_MSG_LATENCY;
@@ -138,6 +139,7 @@ public class BrokerMetricsManager {
     private ObservableLongGauge brokerPermission = new 
NopObservableLongGauge();
     private ObservableLongGauge topicNum = new NopObservableLongGauge();
     private ObservableLongGauge consumerGroupNum = new 
NopObservableLongGauge();
+    private ObservableLongGauge lmqNum = new NopObservableLongGauge();
 
     // request metrics
     private LongCounter messagesInTotal = new NopLongCounter();
@@ -602,6 +604,13 @@ public class BrokerMetricsManager {
             .setDescription("Active subscription group number")
             .ofLongs()
             .buildWithCallback(measurement -> 
measurement.record(brokerController.getSubscriptionGroupManager().getSubscriptionGroupTable().size(),
 newAttributesBuilder().build()));
+
+        if (messageStore.getMessageStoreConfig().isEnableLmq()) {
+            lmqNum = brokerMeter.gaugeBuilder(GAUGE_LMQ_NUM)
+                .setDescription("Current LMQ number")
+                .ofLongs()
+                .buildWithCallback(measurement -> 
measurement.record(messageStore.getQueueStore().getLmqNum(), 
newAttributesBuilder().build()));
+        }
     }
 
     private void initRequestMetrics() {