Merge pull request #969 from DataDog/labbati/jax-rs-op-name

Static operation names for JaxRS instrumentation to be used as root span

dd-java-agent/instrumentation/jax-rs-annotations/src/main/java/datadog/trace/instrumentation/jaxrs/JaxRsAnnotationsDecorator.java

@@ -3,6 +3,7 @@ package datadog.trace.instrumentation.jaxrs;
 import static datadog.trace.bootstrap.WeakMap.Provider.newWeakMap;
 
 import datadog.trace.agent.decorator.BaseDecorator;
+import datadog.trace.api.DDSpanTypes;
 import datadog.trace.api.DDTags;
 import datadog.trace.bootstrap.WeakMap;
 import io.opentracing.Scope;
@@ -36,13 +37,41 @@ public class JaxRsAnnotationsDecorator extends BaseDecorator {
     return "jax-rs-controller";
   }
 
-  public void updateParent(final Scope scope, final Method method) {
+  public void onControllerStart(final Scope scope, final Scope parent, final Method method) {
+    final String resourceName = getPathResourceName(method);
+    updateParent(parent, resourceName);
+
+    final Span span = scope.span();
+    span.setTag(DDTags.SPAN_TYPE, DDSpanTypes.HTTP_SERVER);
+
+    // When jax-rs is the root, we want to name using the path, otherwise use the class/method.
+    final boolean isRootScope = parent == null;
+    if (isRootScope && !resourceName.isEmpty()) {
+      span.setTag(DDTags.RESOURCE_NAME, resourceName);
+    } else {
+      span.setTag(DDTags.RESOURCE_NAME, DECORATE.spanNameForMethod(method));
+    }
+  }
+
+  private void updateParent(final Scope scope, final String resourceName) {
     if (scope == null) {
       return;
     }
     final Span span = scope.span();
     Tags.COMPONENT.set(span, "jax-rs");
 
+    if (!resourceName.isEmpty()) {
+      span.setTag(DDTags.RESOURCE_NAME, resourceName);
+    }
+  }
+
+  /**
+   * Returns the resource name given a JaxRS annotated method. Results are cached so this method can
+   * be called multiple times without significantly impacting performance.
+   *
+   * @return The result can be an empty string but will never be {@code null}.
+   */
+  private String getPathResourceName(final Method method) {
     final Class<?> target = method.getDeclaringClass();
     Map<Method, String> classMap = resourceNames.get(target);
 
@@ -61,9 +90,7 @@ public class JaxRsAnnotationsDecorator extends BaseDecorator {
       classMap.put(method, resourceName);
     }
 
-    if (!resourceName.isEmpty()) {
-      span.setTag(DDTags.RESOURCE_NAME, resourceName);
-    }
+    return resourceName;
   }
 
   private String locateHttpMethod(final Method method) {

dd-java-agent/instrumentation/jax-rs-annotations/src/main/java/datadog/trace/instrumentation/jaxrs/JaxRsAnnotationsInstrumentation.java

@@ -10,6 +10,7 @@ import static net.bytebuddy.matcher.ElementMatchers.named;
 import com.google.auto.service.AutoService;
 import datadog.trace.agent.tooling.Instrumenter;
 import io.opentracing.Scope;
+import io.opentracing.Tracer;
 import io.opentracing.util.GlobalTracer;
 import java.lang.reflect.Method;
 import java.util.Map;
@@ -21,6 +22,8 @@ import net.bytebuddy.matcher.ElementMatcher;
 @AutoService(Instrumenter.class)
 public final class JaxRsAnnotationsInstrumentation extends Instrumenter.Default {
 
+  private static final String JAX_ENDPOINT_OPERATION_NAME = "jax-rs.request";
+
   public JaxRsAnnotationsInstrumentation() {
     super("jax-rs", "jaxrs", "jax-rs-annotations");
   }
@@ -57,13 +60,12 @@ public final class JaxRsAnnotationsInstrumentation extends Instrumenter.Default
 
     @Advice.OnMethodEnter(suppress = Throwable.class)
     public static Scope nameSpan(@Advice.Origin final Method method) {
+      final Tracer tracer = GlobalTracer.get();
       // Rename the parent span according to the path represented by these annotations.
-      final Scope scope = GlobalTracer.get().scopeManager().active();
-      DECORATE.updateParent(scope, method);
-
-      // Now create a span representing the method execution.
-      final String operationName = DECORATE.spanNameForMethod(method);
-      return DECORATE.afterStart(GlobalTracer.get().buildSpan(operationName).startActive(true));
+      final Scope parent = tracer.scopeManager().active();
+      final Scope scope = tracer.buildSpan(JAX_ENDPOINT_OPERATION_NAME).startActive(true);
+      DECORATE.onControllerStart(scope, parent, method);
+      return DECORATE.afterStart(scope);
     }
 
     @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)

dd-java-agent/instrumentation/jax-rs-annotations/src/test/groovy/JaxRsAnnotationsInstrumentationTest.groovy

@@ -14,7 +14,31 @@ import static datadog.trace.instrumentation.jaxrs.JaxRsAnnotationsDecorator.DECO
 
 class JaxRsAnnotationsInstrumentationTest extends AgentTestRunner {
 
-  def "span named '#name' from annotations on class"() {
+  def "instrumentation can be used as root span and resource is set to METHOD PATH"() {
+    setup:
+    new Jax() {
+      @POST
+      @Path("/a")
+      void call() {}
+    }.call()
+
+    expect:
+    assertTraces(1) {
+      trace(0, 1) {
+        span(0) {
+          operationName "jax-rs.request"
+          resourceName "POST /a"
+          spanType "web"
+          tags {
+            "$Tags.COMPONENT.key" "jax-rs-controller"
+            defaultTags()
+          }
+        }
+      }
+    }
+  }
+
+  def "span named '#name' from annotations on class when is not root span"() {
     setup:
     def startingCacheSize = DECORATE.resourceNames.size()
     runUnderTrace("test") {
@@ -34,8 +58,9 @@ class JaxRsAnnotationsInstrumentationTest extends AgentTestRunner {
           }
         }
         span(1) {
-          operationName "${className}.call"
+          operationName "jax-rs.request"
           resourceName "${className}.call"
+          spanType "web"
           childOf span(0)
           tags {
             "$Tags.COMPONENT.key" "jax-rs-controller"