Change OpenCensus shim default sampler to defer to OpenTelemetry

open-telemetry · Jul 7, 2023 · 6a11538 · 6a11538
1 parent aab7159
commit 6a11538
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Showing 2 changed files with 21 additions and 3 deletions.
diff --git a/...s-shim/src/main/java/io/opentelemetry/opencensusshim/OpenTelemetryTraceComponentImpl.java b/...s-shim/src/main/java/io/opentelemetry/opencensusshim/OpenTelemetryTraceComponentImpl.java
@@ -12,8 +12,10 @@
 import io.opencensus.trace.TraceComponent;
 import io.opencensus.trace.Tracer;
 import io.opencensus.trace.config.TraceConfig;
+import io.opencensus.trace.config.TraceParams;
 import io.opencensus.trace.export.ExportComponent;
 import io.opencensus.trace.propagation.PropagationComponent;
+import io.opencensus.trace.samplers.Samplers;
 
 /**
  * Implementation of the {@link TraceComponent} for OpenTelemetry migration, which uses the
@@ -25,7 +27,7 @@ public final class OpenTelemetryTraceComponentImpl extends TraceComponent {
       new OpenTelemetryPropagationComponentImpl();
   private final ExportComponent noopExportComponent = ExportComponent.newNoopExportComponent();
   private final Clock clock;
-  private final TraceConfig traceConfig = new TraceConfigImpl();
+  private final TraceConfig traceConfig = makeTraceConfig();
   private final Tracer tracer;
 
   /** Public constructor to be used with reflection loading. */
@@ -60,4 +62,13 @@ public ExportComponent getExportComponent() {
   public TraceConfig getTraceConfig() {
     return traceConfig;
   }
+
+  private static TraceConfig makeTraceConfig() {
+    // Use the default TraceParams except use an always-on sampler. This defers the
+    // sampling decision to OpenTelemetry
+    TraceConfig traceConfig = new TraceConfigImpl();
+    traceConfig.updateActiveTraceParams(
+        TraceParams.DEFAULT.toBuilder().setSampler(Samplers.alwaysSample()).build());
+    return traceConfig;
+  }
 }
diff --git a/opencensus-shim/src/test/java/io/opentelemetry/opencensusshim/InteroperabilityTest.java b/opencensus-shim/src/test/java/io/opentelemetry/opencensusshim/InteroperabilityTest.java
@@ -322,7 +322,14 @@ public void testNoSampleDoesNotExport() {
   }
 
   @Test
-  public void testNoRecordDoesNotExport() {
+  public void testOpenCensusSamplerIsAlwaysOn() {
+    // OpenTelemetryTraceComponentImpl provides this behavior
+    assertThat(Tracing.getTraceConfig().getActiveTraceParams().getSampler())
+        .isEqualTo(Samplers.alwaysSample());
+  }
+
+  @Test
+  public void testByDefaultDoesExport() {
     io.opencensus.trace.Tracer tracer = Tracing.getTracer();
     try (io.opencensus.common.Scope scope =
         tracer.spanBuilder("OpenCensusSpan").setRecordEvents(false).startScopedSpan()) {
@@ -333,7 +340,7 @@ public void testNoRecordDoesNotExport() {
       span.putAttribute("testKey", AttributeValue.stringAttributeValue("testValue"));
     }
     Tracing.getExportComponent().shutdown();
-    verify(spanExporter, never()).export(anyCollection());
+    verify(spanExporter, times(1)).export(anyCollection());
   }
 
   private static void createOpenCensusScopedSpanWithChildSpan(