enable experimental runtime metrics (#327)

* enable experimental runtime metrics

README.md

@@ -57,6 +57,11 @@ The stacktrace is stored in the [`code.stacktrace`](https://opentelemetry.io/doc
 
 The minimum span duration can be configured with `elastic.otel.span.stack.trace.min.duration` (in milliseconds, defaults to 5ms).
 
+### Runtime metrics
+
+Experimental runtime metrics are enabled by default.
+Set `otel.instrumentation.runtime-telemetry.emit-experimental-telemetry` to `false` to disable them.
+
 ### Breakdown metrics
 
 Breakdown metrics currently require a custom Elasticsearch ingest pipeline.

custom/src/main/java/co/elastic/otel/ElasticAutoConfigurationCustomizerprovider.java → custom/src/main/java/co/elastic/otel/ElasticAutoConfigurationCustomizerProvider.java

@@ -21,16 +21,19 @@
 import com.google.auto.service.AutoService;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizer;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizerProvider;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
 
 @AutoService(AutoConfigurationCustomizerProvider.class)
-public class ElasticAutoConfigurationCustomizerprovider
+public class ElasticAutoConfigurationCustomizerProvider
     implements AutoConfigurationCustomizerProvider {
 
   private static final String DISABLED_RESOURCE_PROVIDERS = "otel.java.disabled.resource.providers";
+  private static final String RUNTIME_EXPERIMENTAL_TELEMETRY =
+      "otel.instrumentation.runtime-telemetry.emit-experimental-telemetry";
 
   @Override
   public void customize(AutoConfigurationCustomizer autoConfiguration) {
@@ -41,26 +44,31 @@ public void customize(AutoConfigurationCustomizer autoConfiguration) {
                 // span processor registration
                 sdkTracerProviderBuilder.addSpanProcessor(
                     ElasticExtension.INSTANCE.getSpanProcessor()))
-        .addPropertiesCustomizer(
-            configProperties -> {
-              Set<String> disabledConfig =
-                  new HashSet<>(configProperties.getList(DISABLED_RESOURCE_PROVIDERS));
-
-              // disabling embedded resource providers
-
-              // disable upstream distro name & version provider
-              disabledConfig.add(
-                  "io.opentelemetry.javaagent.tooling.DistroVersionResourceProvider");
-
-              Map<String, String> config = new HashMap<>();
-              config.put(DISABLED_RESOURCE_PROVIDERS, String.join(",", disabledConfig));
-
-              return config;
-            })
+        .addPropertiesCustomizer(ElasticAutoConfigurationCustomizerProvider::propertiesCustomizer)
         .addSpanExporterCustomizer(
             (spanExporter, configProperties) ->
                 // wrap the original span exporter
                 ElasticExtension.INSTANCE.wrapSpanExporter(spanExporter))
         .addMetricExporterCustomizer((exporter, config) -> new ElasticMetricExporter(exporter));
   }
+
+  static Map<String, String> propertiesCustomizer(ConfigProperties configProperties) {
+    Set<String> disabledResourceProviders =
+        new HashSet<>(configProperties.getList(DISABLED_RESOURCE_PROVIDERS));
+
+    // disable upstream distro name & version provider
+    disabledResourceProviders.add(
+        "io.opentelemetry.javaagent.tooling.DistroVersionResourceProvider");
+
+    Map<String, String> config = new HashMap<>();
+
+    // enable experimental telemetry metrics by default if not explicitly disabled
+    boolean experimentalTelemetry =
+        configProperties.getBoolean(RUNTIME_EXPERIMENTAL_TELEMETRY, true);
+    config.put(RUNTIME_EXPERIMENTAL_TELEMETRY, Boolean.toString(experimentalTelemetry));
+
+    config.put(DISABLED_RESOURCE_PROVIDERS, String.join(",", disabledResourceProviders));
+
+    return config;
+  }
 }

custom/src/test/java/co/elastic/otel/ElasticAutoConfigurationCustomizerproviderTest.java

@@ -0,0 +1,70 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you 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
+ *
+ *   http://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.
+ */
+package co.elastic.otel;
+
+import static co.elastic.otel.ElasticAutoConfigurationCustomizerProvider.propertiesCustomizer;
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.opentelemetry.javaagent.tooling.EmptyConfigProperties;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.DefaultConfigProperties;
+import java.util.HashMap;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
+
+class ElasticAutoConfigurationCustomizerProviderTest {
+
+  @Test
+  void defaultConfiguration() {
+    Map<String, String> config = propertiesCustomizer(EmptyConfigProperties.INSTANCE);
+    assertThat(config)
+        .describedAs("upstream distro version resource provider must be disabled")
+        .containsEntry(
+            "otel.java.disabled.resource.providers",
+            "io.opentelemetry.javaagent.tooling.DistroVersionResourceProvider");
+
+    assertThat(config)
+        .describedAs("runtime experimental metrics must be enabled")
+        .containsEntry(
+            "otel.instrumentation.runtime-telemetry.emit-experimental-telemetry", "true");
+  }
+
+  @Test
+  void disableCustomResourceProvider() {
+    Map<String, String> userConfig = new HashMap<>();
+    userConfig.put("otel.java.disabled.resource.providers", "my.disabled.provider.Provider");
+    Map<String, String> config = propertiesCustomizer(DefaultConfigProperties.create(userConfig));
+    String value = config.get("otel.java.disabled.resource.providers");
+    assertThat(value)
+        .satisfies(
+            v ->
+                assertThat(v.split(","))
+                    .containsExactly(
+                        "io.opentelemetry.javaagent.tooling.DistroVersionResourceProvider",
+                        "my.disabled.provider.Provider"));
+  }
+
+  @Test
+  void disableExperimentalRuntimeMetrics() {
+    Map<String, String> userConfig = new HashMap<>();
+    userConfig.put("otel.instrumentation.runtime-telemetry.emit-experimental-telemetry", "false");
+    Map<String, String> config = propertiesCustomizer(DefaultConfigProperties.create(userConfig));
+    String value = config.get("otel.instrumentation.runtime-telemetry.emit-experimental-telemetry");
+    assertThat(value).isEqualTo("false");
+  }
+}