(pulsar) branch branch-4.0 updated: [fix][broker]pulsar_ml_reads_inflight_bytes and pulsar_ml_reads_available_inflight_bytes are 0 at the same time (#25105)

[technoboy]

This is an automated email from the ASF dual-hosted git repository.

technoboy pushed a commit to branch branch-4.0
in repository https://gitbox.apache.org/repos/asf/pulsar.git


The following commit(s) were added to refs/heads/branch-4.0 by this push:
     new 8849484b557 [fix][broker]pulsar_ml_reads_inflight_bytes and 
pulsar_ml_reads_available_inflight_bytes are 0 at the same time (#25105)
8849484b557 is described below

commit 8849484b5578ec08a7af9a8a4d9e2133ac7fd33c
Author: Penghui Li <peng...@apache.org>
AuthorDate: Mon Dec 22 23:07:25 2025 -0800

    [fix][broker]pulsar_ml_reads_inflight_bytes and 
pulsar_ml_reads_available_inflight_bytes are 0 at the same time (#25105)
---
 .../bookkeeper/mledger/impl/cache/InflightReadsLimiter.java  |  7 +++++--
 .../mledger/impl/cache/InflightReadsLimiterTest.java         | 12 ++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git 
a/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/cache/InflightReadsLimiter.java
 
b/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/cache/InflightReadsLimiter.java
index cda8e975544..616accf8b4f 100644
--- 
a/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/cache/InflightReadsLimiter.java
+++ 
b/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/cache/InflightReadsLimiter.java
@@ -42,7 +42,8 @@ public class InflightReadsLimiter implements AutoCloseable {
 
     @PulsarDeprecatedMetric(newMetricName = 
INFLIGHT_READS_LIMITER_LIMIT_METRIC_NAME)
     @Deprecated
-    private static final Gauge PULSAR_ML_READS_BUFFER_SIZE = Gauge
+    @VisibleForTesting
+    static final Gauge PULSAR_ML_READS_BUFFER_SIZE = Gauge
             .build()
             .name("pulsar_ml_reads_inflight_bytes")
             .help("Estimated number of bytes retained by data read from 
storage or cache")
@@ -55,7 +56,8 @@ public class InflightReadsLimiter implements AutoCloseable {
 
     @PulsarDeprecatedMetric(newMetricName = 
INFLIGHT_READS_LIMITER_USAGE_METRIC_NAME)
     @Deprecated
-    private static final Gauge PULSAR_ML_READS_AVAILABLE_BUFFER_SIZE = Gauge
+    @VisibleForTesting
+    static final Gauge PULSAR_ML_READS_AVAILABLE_BUFFER_SIZE = Gauge
             .build()
             .name("pulsar_ml_reads_available_inflight_bytes")
             .help("Available space for inflight data read from storage or 
cache")
@@ -87,6 +89,7 @@ public class InflightReadsLimiter implements AutoCloseable {
         if (maxReadsInFlightSize > 0) {
             enabled = true;
             this.queuedHandles = new ArrayDeque<>();
+            updateMetrics();
         } else {
             enabled = false;
             this.queuedHandles = null;
diff --git 
a/managed-ledger/src/test/java/org/apache/bookkeeper/mledger/impl/cache/InflightReadsLimiterTest.java
 
b/managed-ledger/src/test/java/org/apache/bookkeeper/mledger/impl/cache/InflightReadsLimiterTest.java
index 7475b620f57..98c9e939cc6 100644
--- 
a/managed-ledger/src/test/java/org/apache/bookkeeper/mledger/impl/cache/InflightReadsLimiterTest.java
+++ 
b/managed-ledger/src/test/java/org/apache/bookkeeper/mledger/impl/cache/InflightReadsLimiterTest.java
@@ -538,6 +538,18 @@ public class InflightReadsLimiterTest {
                 .isEqualTo(maxReadsInFlightSize);
     }
 
+    @Test
+    public void testPrometheusMetrics() throws Exception {
+        long maxReadsInFlightSize = 100;
+        @Cleanup
+        InflightReadsLimiter limiter = new 
InflightReadsLimiter(maxReadsInFlightSize, ACQUIRE_QUEUE_SIZE,
+                ACQUIRE_TIMEOUT_MILLIS, mock(ScheduledExecutorService.class), 
OpenTelemetry.noop());
+
+        
Assertions.assertThat(limiter.PULSAR_ML_READS_BUFFER_SIZE.get()).isZero();
+        
Assertions.assertThat(limiter.PULSAR_ML_READS_AVAILABLE_BUFFER_SIZE.get())
+                .isEqualTo(maxReadsInFlightSize);
+    }
+
     private Pair<OpenTelemetrySdk, InMemoryMetricReader> 
buildOpenTelemetryAndReader() {
         var metricReader = InMemoryMetricReader.create();
         var openTelemetry = AutoConfiguredOpenTelemetrySdk.builder()