check for well-known method

Author: zeitlinger

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/semconv/rpc/RpcAttributesGetter.java

@@ -46,12 +46,18 @@ default Long getResponseSize(REQUEST request) {
    *     method is unavailable
    */
   @Nullable
-  default String getFullMethod(REQUEST request) {
-    String service = getService(request);
-    String method = getMethod(request);
-    if (service == null || method == null) {
-      return null;
-    }
-    return service + "/" + method;
+  default String getRpcMethod(REQUEST request) {
+    return null;
+  }
+
+  /**
+   * Returns whether the RPC method is a well-known method.
+   *
+   * <p>This is used to determine whether to set the {@code rpc.method} attribute to the actual
+   * method name, or to set it to {@code "_OTHER"} and store the actual method name in {@code
+   * rpc.method_original}.
+   */
+  default boolean isWellKnownMethod(REQUEST request) {
+    return false;
   }
 }

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/semconv/rpc/RpcCommonAttributesExtractor.java

@@ -29,6 +29,9 @@ abstract class RpcCommonAttributesExtractor<REQUEST, RESPONSE>
   // use RPC_SYSTEM_NAME for stable semconv
   static final AttributeKey<String> RPC_SYSTEM = AttributeKey.stringKey("rpc.system");
 
+  static final AttributeKey<String> RPC_METHOD_ORIGINAL =
+      AttributeKey.stringKey("rpc.method_original");
+
   private final RpcAttributesGetter<REQUEST> getter;
 
   RpcCommonAttributesExtractor(RpcAttributesGetter<REQUEST> getter) {
@@ -44,7 +47,13 @@ public final void onStart(AttributesBuilder attributes, Context parentContext, R
           attributes,
           RPC_SYSTEM_NAME,
           system == null ? null : SemconvStability.stableRpcSystemName(system));
-      internalSet(attributes, RPC_METHOD, getter.getFullMethod(request));
+      String method = getter.getRpcMethod(request);
+      if (getter.isWellKnownMethod(request)) {
+        internalSet(attributes, RPC_METHOD, method);
+      } else {
+        internalSet(attributes, RPC_METHOD_ORIGINAL, method);
+        internalSet(attributes, RPC_METHOD, "_OTHER");
+      }
     }
 
     if (SemconvStability.emitOldRpcSemconv()) {

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/semconv/rpc/RpcSpanNameExtractor.java

@@ -6,6 +6,7 @@
 package io.opentelemetry.instrumentation.api.incubator.semconv.rpc;
 
 import io.opentelemetry.instrumentation.api.instrumenter.SpanNameExtractor;
+import io.opentelemetry.instrumentation.api.internal.SemconvStability;
 
 /** A {@link SpanNameExtractor} for RPC requests. */
 public final class RpcSpanNameExtractor<REQUEST> implements SpanNameExtractor<REQUEST> {
@@ -27,6 +28,10 @@ private RpcSpanNameExtractor(RpcAttributesGetter<REQUEST> getter) {
 
   @Override
   public String extract(REQUEST request) {
+    if (SemconvStability.emitStableRpcSemconv()) {
+      return getter.getRpcMethod(request);
+    }
+
     String service = getter.getService(request);
     String method = getter.getMethod(request);
     if (service == null || method == null) {

instrumentation-api-incubator/src/test/java/io/opentelemetry/instrumentation/api/incubator/semconv/rpc/RpcAttributesExtractorTest.java

@@ -5,6 +5,7 @@
 
 package io.opentelemetry.instrumentation.api.incubator.semconv.rpc;
 
+import static io.opentelemetry.instrumentation.api.incubator.semconv.rpc.RpcCommonAttributesExtractor.RPC_METHOD_ORIGINAL;
 import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat;
 import static org.assertj.core.api.Assertions.entry;
 
@@ -18,12 +19,18 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import javax.annotation.Nullable;
 import org.junit.jupiter.api.Test;
 
 class RpcAttributesExtractorTest {
 
-  enum TestGetter implements RpcAttributesGetter<Map<String, String>> {
-    INSTANCE;
+  private static class TestGetter implements RpcAttributesGetter<Map<String, String>> {
+
+    private final boolean wellKnownMethod;
+
+    private TestGetter(boolean wellKnownMethod) {
+      this.wellKnownMethod = wellKnownMethod;
+    }
 
     @Override
     public String getSystem(Map<String, String> request) {
@@ -39,16 +46,42 @@ public String getService(Map<String, String> request) {
     public String getMethod(Map<String, String> request) {
       return request.get("method");
     }
+
+    @Nullable
+    @Override
+    public String getRpcMethod(Map<String, String> request) {
+      String service = getService(request);
+      String method = getMethod(request);
+      if (service == null || method == null) {
+        return null;
+      }
+      return service + "/" + method;
+    }
+
+    @Override
+    public boolean isWellKnownMethod(Map<String, String> stringStringMap) {
+      return wellKnownMethod;
+    }
   }
 
   @Test
   void server() {
-    testExtractor(RpcServerAttributesExtractor.create(TestGetter.INSTANCE));
+    testExtractor(RpcServerAttributesExtractor.create(new TestGetter(false)), "my.Service/Method");
+  }
+
+  @Test
+  void serverWellKnown() {
+    testExtractor(RpcServerAttributesExtractor.create(new TestGetter(true)), null);
   }
 
   @Test
   void client() {
-    testExtractor(RpcClientAttributesExtractor.create(TestGetter.INSTANCE));
+    testExtractor(RpcClientAttributesExtractor.create(new TestGetter(false)), "my.Service/Method");
+  }
+
+  @Test
+  void clientWellKnown() {
+    testExtractor(RpcClientAttributesExtractor.create(new TestGetter(true)), null);
   }
 
   // Stable semconv keys
@@ -65,7 +98,8 @@ void client() {
   private static final AttributeKey<String> RPC_METHOD =
       io.opentelemetry.semconv.incubating.RpcIncubatingAttributes.RPC_METHOD;
 
-  private static void testExtractor(AttributesExtractor<Map<String, String>, Void> extractor) {
+  private static void testExtractor(
+      AttributesExtractor<Map<String, String>, Void> extractor, @Nullable String originalMethod) {
     Map<String, String> request = new HashMap<>();
     request.put("service", "my.Service");
     request.put("method", "Method");
@@ -80,7 +114,12 @@ private static void testExtractor(AttributesExtractor<Map<String, String>, Void>
 
     if (SemconvStability.emitStableRpcSemconv()) {
       expectedEntries.add(entry(RPC_SYSTEM_NAME, "test"));
-      expectedEntries.add(entry(RPC_METHOD, "my.Service/Method"));
+      if (originalMethod != null) {
+        expectedEntries.add(entry(RPC_METHOD_ORIGINAL, originalMethod));
+        expectedEntries.add(entry(RPC_METHOD, "_OTHER"));
+      } else {
+        expectedEntries.add(entry(RPC_METHOD, "my.Service/Method"));
+      }
     }
 
     if (SemconvStability.emitOldRpcSemconv()) {