Support OTLP runtime metrics with OTel-native naming

dd-java-agent/agent-jmxfetch/build.gradle

@@ -25,6 +25,14 @@ dependencies {
   api libs.slf4j
   api project(':internal-api')
   api project(':dd-java-agent:agent-bootstrap')
+
+  // The opentelemetry-api compileOnly is only for io.opentelemetry.api.common.Attributes /
+  // AttributeKey used to label the recorded measurements; everything else comes from otel-bootstrap.
+  compileOnly group: 'io.opentelemetry', name: 'opentelemetry-api', version: '1.47.0'
+  // JvmOtlpRuntimeMetrics registers JVM runtime instruments directly against the
+  // bootstrap-level OTel metric registry. otel-bootstrap vendors and repackages the
+  // OTel API at build time so this won't conflict with anything in the customer app.
+  compileOnly project(':dd-java-agent:agent-otel:otel-bootstrap')
 }
 
 tasks.named("shadowJar", ShadowJar) {

dd-java-agent/agent-jmxfetch/src/main/java/datadog/trace/agent/jmxfetch/JMXFetch.java

@@ -9,6 +9,7 @@
 import datadog.metrics.api.statsd.StatsDClientManager;
 import datadog.trace.api.Config;
 import datadog.trace.api.GlobalTracer;
+import datadog.trace.api.InstrumenterConfig;
 import datadog.trace.api.flare.TracerFlare;
 import datadog.trace.api.telemetry.LogCollector;
 import de.thetaphi.forbiddenapis.SuppressForbidden;
@@ -93,9 +94,16 @@ private static void run(final StatsDClientManager statsDClientManager, final Con
     final StatsDClient statsd = statsDClientManager.statsDClient(host, port, namedPipe, null, null);
     final AgentStatsdReporter reporter = new AgentStatsdReporter(statsd);
 
+    // When the OTLP exporter is collecting JVM runtime metrics, skip the default JMXFetch
+    // JVM config to avoid double-reporting.
+    final boolean otlpRuntimeMetricsEnabled =
+        InstrumenterConfig.get().isMetricsOtelEnabled() && config.isMetricsOtlpExporterEnabled();
+
     TracerFlare.addReporter(reporter);
     final List<String> defaultConfigs = new ArrayList<>();
-    defaultConfigs.add(DEFAULT_CONFIG);
+    if (!otlpRuntimeMetricsEnabled) {
+      defaultConfigs.add(DEFAULT_CONFIG);
+    }
     if (config.isJmxFetchIntegrationEnabled(Collections.singletonList("websphere"), false)) {
       defaultConfigs.add(WEBSPHERE_CONFIG);
     }
@@ -167,6 +175,14 @@ public void run() {
               }
             });
     thread.setContextClassLoader(JMXFetch.class.getClassLoader());
+
+    // Register JVM runtime metric callbacks against the OtelMeterProvider so the OTLP
+    // exporter started by CoreTracer collects them. Started here so it rides the same
+    // delayed-start path as JMXFetch itself.
+    if (otlpRuntimeMetricsEnabled) {
+      JvmOtlpRuntimeMetrics.start();
+    }
+
     thread.start();
   }