Propagate Tracer when building TChannel

While workflows still capture the tracing information in the headers, we should pass the Tracer to TChannel so that we correctly trace all RPC requests sent to the Cadence server.

Ensure that Tracer can't be set to null and correct the testing library version to avoid classpath conflicts.

Author: natemort

build.gradle

@@ -100,7 +100,7 @@ dependencies {
     testCompile group: 'com.googlecode.junit-toolbox', name: 'junit-toolbox', version: '2.4'
     testCompile group: 'ch.qos.logback', name: 'logback-classic', version: '1.2.3'
     testCompile group: 'io.grpc', name: 'grpc-testing', version: '1.54.2'
-    testImplementation 'io.opentracing:opentracing-mock:0.33.0'
+    testImplementation 'io.opentracing:opentracing-mock:0.32.0'
     testImplementation group: 'org.mockito', name: 'mockito-core', version: '4.5.1'
     testImplementation "org.mockito:mockito-inline:4.5.1" // for mocking final classes
 }

src/main/java/com/uber/cadence/serviceclient/ClientOptions.java

@@ -26,6 +26,7 @@
 import io.grpc.ManagedChannel;
 import io.opentracing.Tracer;
 import io.opentracing.noop.NoopTracerFactory;
+import io.opentracing.util.GlobalTracer;
 import java.util.Map;
 
 public class ClientOptions {
@@ -130,7 +131,13 @@ private ClientOptions(Builder builder) {
     }
     this.authProvider = builder.authProvider;
     this.isolationGroup = builder.isolationGroup;
-    this.tracer = builder.tracer;
+    if (builder.tracer != null) {
+      this.tracer = builder.tracer;
+    } else {
+      // Default value is GlobalTracer. If the user overrides it with null, fall back to NoopTracer.
+      // We need some tracer instance
+      this.tracer = NoopTracerFactory.create();
+    }
   }
 
   public static ClientOptions defaultInstance() {
@@ -233,8 +240,8 @@ public static class Builder {
     private IAuthorizationProvider authProvider;
     private FeatureFlags featureFlags;
     private String isolationGroup;
-    // by default NoopTracer
-    private Tracer tracer = NoopTracerFactory.create();
+    // by default GlobalTracer
+    private Tracer tracer = GlobalTracer.get();
 
     private Builder() {}
 

src/main/java/com/uber/cadence/serviceclient/WorkflowServiceTChannel.java

@@ -86,7 +86,8 @@ public class WorkflowServiceTChannel implements IWorkflowService {
   public WorkflowServiceTChannel(ClientOptions options) {
     this.options = options;
     this.thriftHeaders = getThriftHeaders(options);
-    this.tChannel = new TChannel.Builder(options.getClientAppName()).build();
+    this.tChannel =
+        new TChannel.Builder(options.getClientAppName()).setTracer(options.getTracer()).build();
     this.tracingPropagator = new TracingPropagator(options.getTracer());
     this.tracer = options.getTracer();
 

src/test/java/com/uber/cadence/internal/sync/WorkflowClientInternalTest.java

@@ -116,8 +116,18 @@ public void testEnqueueStart_includesTracing() {
     stub.enqueueStart("input");
 
     StartWorkflowExecutionAsyncRequest request = requestFuture.getNow(null).getStartRequest();
-    assertEquals(1, fakeService.getTracer().finishedSpans().size());
-    MockSpan mockSpan = fakeService.getTracer().finishedSpans().get(0);
+    MockSpan mockSpan =
+        fakeService
+            .getTracer()
+            .finishedSpans()
+            .stream()
+            .filter(span -> "cadence-StartWorkflowExecutionAsync".equals(span.operationName()))
+            .findFirst()
+            .orElseThrow(
+                () ->
+                    new AssertionError(
+                        "No span found for StartWorkflowExecutionAsync:"
+                            + fakeService.getTracer().finishedSpans()));
     assertEquals(
         mockSpan.context().toTraceId(),
         Charsets.UTF_8
@@ -269,8 +279,21 @@ public void testEnqueueSignalWithStart_includesTracing() {
 
     SignalWithStartWorkflowExecutionRequest request =
         requestFuture.getNow(null).getSignalWithStartRequest().getRequest();
-    assertEquals(1, fakeService.getTracer().finishedSpans().size());
-    MockSpan mockSpan = fakeService.getTracer().finishedSpans().get(0);
+    assertEquals(2, fakeService.getTracer().finishedSpans().size());
+    MockSpan mockSpan =
+        fakeService
+            .getTracer()
+            .finishedSpans()
+            .stream()
+            .filter(
+                span ->
+                    "cadence-SignalWithStartWorkflowExecutionAsync".equals(span.operationName()))
+            .findFirst()
+            .orElseThrow(
+                () ->
+                    new AssertionError(
+                        "No span found for SignalWithStartWorkflowExecutionAsync:"
+                            + fakeService.getTracer().finishedSpans()));
     assertEquals(
         mockSpan.context().toTraceId(),
         Charsets.UTF_8.decode(request.getHeader().getFields().get("traceid")).toString());