Merge branch '1.14.x'

Author: shakuzen

gradle/libs.versions.toml

@@ -75,7 +75,7 @@ spectator-atlas = "1.8.6"
 spring5 = "5.3.39"
 spring6 = "6.2.3"
 spring-javaformat = "0.0.43"
-testcontainers = "1.20.4"
+testcontainers = "1.20.5"
 tomcat = "8.5.100"
 wavefront = "3.4.3"
 wiremock = "2.35.2"

implementations/micrometer-registry-stackdriver/build.gradle

@@ -8,8 +8,9 @@ dependencies {
         exclude group: 'com.google.guava', module: 'listenablefuture'
     }
     api libs.googleOauth2Http
-    implementation 'org.slf4j:slf4j-api'
-    compileOnly 'ch.qos.logback:logback-classic'
+    implementation libs.slf4jApi
+    compileOnly libs.logback12
+    testRuntimeOnly libs.logback12
     // needed for extending TimeWindowPercentileHistogram in StackdriverHistogramUtil
     compileOnly libs.hdrhistogram
 

implementations/micrometer-registry-stackdriver/src/main/java/io/micrometer/stackdriver/StackdriverMeterRegistry.java

@@ -557,10 +557,12 @@ Distribution distribution(HistogramSnapshot snapshot, boolean timeDomain) {
                 bucketBoundaries.add(0.0);
             }
 
+            double mean = cumulativeCount == 0 ? 0.0 : timeDomain ? snapshot.mean(getBaseTimeUnit()) : snapshot.mean();
+
             return Distribution.newBuilder()
                 // is the mean optional? better to not send as it is for a different time
                 // window than the histogram
-                .setMean(timeDomain ? snapshot.mean(getBaseTimeUnit()) : snapshot.mean())
+                .setMean(mean)
                 .setCount(cumulativeCount)
                 .setBucketOptions(Distribution.BucketOptions.newBuilder()
                     .setExplicitBuckets(

implementations/micrometer-registry-stackdriver/src/test/java/io/micrometer/stackdriver/StackdriverMeterRegistryTest.java

@@ -34,7 +34,9 @@
  */
 class StackdriverMeterRegistryTest {
 
-    StackdriverMeterRegistry meterRegistry = new StackdriverMeterRegistry(new StackdriverConfig() {
+    MockClock clock = new MockClock();
+
+    StackdriverConfig config = new StackdriverConfig() {
         @Override
         public boolean enabled() {
             return false;
@@ -50,7 +52,9 @@ public String projectId() {
         public String get(String key) {
             return null;
         }
-    }, new MockClock());
+    };
+
+    StackdriverMeterRegistry meterRegistry = new StackdriverMeterRegistry(config, clock);
 
     @Test
     @Issue("#1325")
@@ -177,4 +181,20 @@ void distributionWithOneExplicitBucket() {
         assertThat(distribution.getBucketCountsList()).containsExactly(1L, 1L);
     }
 
+    @Test
+    @Issue("#5927")
+    void meanIsZeroWhenCountIsZero() {
+        StackdriverMeterRegistry.Batch batch = meterRegistry.new Batch();
+        // halfway through first step
+        clock.add(config.step().dividedBy(2));
+        // histogram time window will start here
+        DistributionSummary ds = DistributionSummary.builder("ds").serviceLevelObjectives(2).register(meterRegistry);
+        ds.record(3);
+        // 3/4 through the second step; after histogram rollover
+        clock.add(config.step().dividedBy(4).multipliedBy(5));
+        Distribution distribution = batch.distribution(ds.takeSnapshot(), false);
+        assertThat(distribution.getCount()).isZero();
+        assertThat(distribution.getMean()).isZero();
+    }
+
 }

implementations/micrometer-registry-stackdriver/src/test/resources/logback.xml

@@ -0,0 +1,32 @@
+<!--
+
+    Copyright 2025 VMware, Inc.
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+    https://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+
+-->
+<configuration>
+
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <!-- encoders are  by default assigned the type
+             ch.qos.logback.classic.encoder.PatternLayoutEncoder -->
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <root level="info">
+        <appender-ref ref="STDOUT" />
+    </root>
+
+</configuration>