Delay metrics export to post-agent initialization.

open-telemetry · Feb 10, 2022 · d9d8e1c · d9d8e1c
1 parent d22ca7e
commit d9d8e1c
Showing 1 changed file with 81 additions and 6 deletions.
diff --git a/...ter/src/main/java/io/opentelemetry/javaagent/testing/exporter/AgentTestingCustomizer.java b/...ter/src/main/java/io/opentelemetry/javaagent/testing/exporter/AgentTestingCustomizer.java
@@ -5,15 +5,26 @@
 
 package io.opentelemetry.javaagent.testing.exporter;
 
+import static java.util.Objects.requireNonNull;
+
 import com.google.auto.service.AutoService;
+import io.opentelemetry.instrumentation.api.config.Config;
+import io.opentelemetry.javaagent.extension.AgentListener;
+import io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdk;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizer;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizerProvider;
+import io.opentelemetry.sdk.common.CompletableResultCode;
+import io.opentelemetry.sdk.metrics.data.AggregationTemporality;
+import io.opentelemetry.sdk.metrics.export.MetricProducer;
+import io.opentelemetry.sdk.metrics.export.MetricReader;
+import io.opentelemetry.sdk.metrics.export.MetricReaderFactory;
 import io.opentelemetry.sdk.metrics.export.PeriodicMetricReader;
 import io.opentelemetry.sdk.trace.export.SimpleSpanProcessor;
 import java.time.Duration;
+import javax.annotation.Nullable;
 
-@AutoService(AutoConfigurationCustomizerProvider.class)
-public class AgentTestingCustomizer implements AutoConfigurationCustomizerProvider {
+@AutoService({AutoConfigurationCustomizerProvider.class, AgentListener.class})
+public class AgentTestingCustomizer implements AutoConfigurationCustomizerProvider, AgentListener {
 
   static final AgentTestingSpanProcessor spanProcessor =
       new AgentTestingSpanProcessor(
@@ -30,9 +41,73 @@ public void customize(AutoConfigurationCustomizer autoConfigurationCustomizer) {
 
     autoConfigurationCustomizer.addMeterProviderCustomizer(
         (meterProvider, config) ->
-            meterProvider.registerMetricReader(
-                PeriodicMetricReader.builder(AgentTestingExporterFactory.metricExporter)
-                    .setInterval(Duration.ofMillis(300))
-                    .newMetricReaderFactory()));
+            meterProvider.registerMetricReader(StartableMetricReader.INSTANCE));
+  }
+
+  @Override
+  public void afterAgent(
+      Config config, AutoConfiguredOpenTelemetrySdk autoConfiguredOpenTelemetrySdk) {
+    StartableMetricReader.INSTANCE.start();
+  }
+
+  @SuppressWarnings("ImmutableEnumChecker")
+  private enum StartableMetricReader implements MetricReaderFactory, MetricReader {
+    INSTANCE;
+
+    @Nullable private volatile MetricProducer metricProducer;
+
+    private volatile MetricReader delegate = NoopMetricReader.INSTANCE;
+
+    void start() {
+      MetricProducer metricProducer = this.metricProducer;
+      requireNonNull(metricProducer);
+      delegate =
+          PeriodicMetricReader.builder(AgentTestingExporterFactory.metricExporter)
+              .setInterval(Duration.ofMillis(300))
+              .newMetricReaderFactory()
+              .apply(metricProducer);
+    }
+
+    @Nullable
+    @Override
+    public AggregationTemporality getPreferredTemporality() {
+      return delegate.getPreferredTemporality();
+    }
+
+    @Override
+    public CompletableResultCode flush() {
+      return delegate.flush();
+    }
+
+    @Override
+    public CompletableResultCode shutdown() {
+      return delegate.shutdown();
+    }
+
+    @Override
+    public MetricReader apply(MetricProducer metricProducer) {
+      this.metricProducer = metricProducer;
+      return this;
+    }
+  }
+
+  private enum NoopMetricReader implements MetricReader {
+    INSTANCE;
+
+    @Nullable
+    @Override
+    public AggregationTemporality getPreferredTemporality() {
+      return null;
+    }
+
+    @Override
+    public CompletableResultCode flush() {
+      return CompletableResultCode.ofSuccess();
+    }
+
+    @Override
+    public CompletableResultCode shutdown() {
+      return CompletableResultCode.ofSuccess();
+    }
   }
 }