Pre v1.14.2 (#878)

* Fix allocation metric (#864)

* Fix allocation metric

* convert field to local variable

* prepare for v1.14.2 patch release

* update changelog

Co-authored-by: Lauri Tulmin <[email protected]>

Author: breedx-splk

CHANGELOG.md

@@ -8,6 +8,9 @@ and this repository adheres to [Semantic Versioning](https://semver.org/spec/v2.
 
 ## Unreleased
 
+## v1.14.2 - 2022-08-12
+- Fix allocated memory metrics by preventing `WeakReference` from GCing (#864)
+
 ## v1.14.1 - 2022-07-27
 
 ### Bugfixes

README.md

@@ -157,7 +157,7 @@ To extend the instrumentation with the OpenTelemetry Instrumentation for Java,
 you have to use a compatible API version.
 
 <!-- IMPORTANT: do not change comments or break those lines below -->
-The Splunk Distribution of OpenTelemetry Java version <!--SPLUNK_VERSION-->1.14.1<!--SPLUNK_VERSION--> is compatible
+The Splunk Distribution of OpenTelemetry Java version <!--SPLUNK_VERSION-->1.14.2<!--SPLUNK_VERSION--> is compatible
 with:
 
 * OpenTelemetry API version <!--OTEL_VERSION-->1.15.0<!--OTEL_VERSION-->

deployments/cloudfoundry/buildpack/README.md

@@ -40,7 +40,7 @@ If you want to use a specific version of the Java agent in your application, you
 environment variable before application deployment, either using `cf set-env` or the `manifest.yml` file:
 
 ```sh
-$ cf set-env SPLUNK_OTEL_JAVA_VERSION 1.14.1
+$ cf set-env SPLUNK_OTEL_JAVA_VERSION 1.14.2
 ```
 
 By default, the [latest](https://github.com/signalfx/splunk-otel-java/releases/latest) available agent version is used.

instrumentation/jvm-metrics/src/main/java/com/splunk/opentelemetry/instrumentation/jvmmetrics/micrometer/MicrometerAllocatedMemoryMetrics.java

@@ -25,18 +25,21 @@
 import io.micrometer.core.instrument.binder.MeterBinder;
 
 public class MicrometerAllocatedMemoryMetrics implements MeterBinder {
-  private final AllocatedMemoryMetrics allocatedMemoryMetrics = new AllocatedMemoryMetrics();
 
   @Override
   public void bindTo(MeterRegistry registry) {
+    AllocatedMemoryMetrics allocatedMemoryMetrics = new AllocatedMemoryMetrics();
     if (!allocatedMemoryMetrics.isAvailable()) {
       return;
     }
 
+    // FunctionCounter keeps a weak reference to allocatedMemoryMetrics. To ensure it is not
+    // collected we pass a capturing lambda as the function instead of method reference
+    // AllocatedMemoryMetrics::getCumulativeAllocationTotal
     FunctionCounter.builder(
             METRIC_NAME,
             allocatedMemoryMetrics,
-            AllocatedMemoryMetrics::getCumulativeAllocationTotal)
+            (unused) -> allocatedMemoryMetrics.getCumulativeAllocationTotal())
         .description("Approximate sum of heap allocations")
         .baseUnit(BaseUnits.BYTES)
         .tag("type", "heap")