Enforce message event and annotation limits.

packages/opencensus-core/src/trace/model/span-base.ts

@@ -64,9 +64,12 @@ export abstract class SpanBase implements types.Span {
 
   /** The number of dropped attributes. */
   droppedAttributesCount = 0;
-
   /** The number of dropped links. */
   droppedLinksCount = 0;
+  /** The number of dropped annotations. */
+  droppedAnnotationsCount = 0;
+  /** The number of dropped message events. */
+  droppedMessageEventsCount = 0;
 
   /** Constructs a new SpanBaseModel instance. */
   constructor() {
@@ -166,6 +169,11 @@ export abstract class SpanBase implements types.Span {
    */
   addAnnotation(
       description: string, attributes?: types.Attributes, timestamp = 0) {
+    if (this.annotations.length >=
+        this.activeTraceParams.numberOfAnnontationEventsPerSpan) {
+      this.annotations.shift();
+      this.droppedAnnotationsCount++;
+    }
     this.annotations.push({
       'description': description,
       'attributes': attributes,
@@ -203,6 +211,11 @@ export abstract class SpanBase implements types.Span {
    * @param timestamp A time in milliseconds. Defaults to Date.now()
    */
   addMessageEvent(type: string, id: string, timestamp = 0) {
+    if (this.messageEvents.length >=
+        this.activeTraceParams.numberOfMessageEventsPerSpan) {
+      this.messageEvents.shift();
+      this.droppedMessageEventsCount++;
+    }
     this.messageEvents.push({
       'type': type,
       'id': id,

packages/opencensus-core/src/trace/model/types.ts

@@ -329,6 +329,12 @@ export interface Span {
   /** The number of dropped links. */
   droppedLinksCount: number;
 
+  /** The number of dropped annotations. */
+  droppedAnnotationsCount: number;
+
+  /** The number of dropped message events. */
+  droppedMessageEventsCount: number;
+
   /**
    * Adds an atribute to the span.
    * @param key Describes the value added.

packages/opencensus-core/test/test-root-span.ts

@@ -206,6 +206,7 @@ describe('RootSpan', () => {
       rootSpan.addAnnotation('description test', {} as Attributes, Date.now());
 
       assert.ok(rootSpan.annotations.length > 0);
+      assert.equal(rootSpan.droppedAnnotationsCount, 0);
       assert.ok(instanceOfAnnotation(rootSpan.annotations[0]));
     });
   });
@@ -251,6 +252,7 @@ describe('RootSpan', () => {
       rootSpan.addMessageEvent('TYPE_UNSPECIFIED', 'message_event_test_id');
 
       assert.ok(rootSpan.messageEvents.length > 0);
+      assert.equal(rootSpan.droppedMessageEventsCount, 0);
       assert.ok(instanceOfLink(rootSpan.messageEvents[0]));
     });
   });

packages/opencensus-core/test/test-span.ts

@@ -28,7 +28,9 @@ import {Annotation, Attributes, Link} from '../src/trace/model/types';
 const tracer = new CoreTracer();
 tracer.activeTraceParams = {
   numberOfAttributesPerSpan: 32,
-  numberOfLinksPerSpan: 32
+  numberOfLinksPerSpan: 32,
+  numberOfAnnontationEventsPerSpan: 32,
+  numberOfMessageEventsPerSpan: 32
 };
 
 describe('Span', () => {
@@ -226,8 +228,23 @@ describe('Span', () => {
       span.addAnnotation('description test', {} as Attributes, Date.now());
 
       assert.ok(span.annotations.length > 0);
+      assert.equal(span.droppedAnnotationsCount, 0);
       assert.ok(instanceOfAnnotation(span.annotations[0]));
     });
+
+    it('should drop extra annotations', () => {
+      const rootSpan = new RootSpan(tracer);
+      rootSpan.start();
+
+      const span = new Span(rootSpan);
+      span.start();
+      for (let i = 0; i < 40; i++) {
+        span.addAnnotation('description test', {} as Attributes, Date.now());
+      }
+
+      assert.equal(span.annotations.length, 32);
+      assert.equal(span.droppedAnnotationsCount, 8);
+    });
   });
 
   /**
@@ -289,8 +306,23 @@ describe('Span', () => {
       span.addMessageEvent('TYPE_UNSPECIFIED', 'message_event_test_id');
 
       assert.ok(span.messageEvents.length > 0);
+      assert.equal(span.droppedMessageEventsCount, 0);
       assert.ok(instanceOfLink(span.messageEvents[0]));
     });
+
+    it('should drop extra  Message Event', () => {
+      const rootSpan = new RootSpan(tracer);
+      rootSpan.start();
+
+      const span = new Span(rootSpan);
+      span.start();
+      for (let i = 0; i < 35; i++) {
+        span.addMessageEvent('TYPE_UNSPECIFIED', 'message_event_test_id');
+      }
+
+      assert.equal(span.messageEvents.length, 32);
+      assert.equal(span.droppedMessageEventsCount, 3);
+    });
   });
 
   describe('setStatus()', () => {

packages/opencensus-exporter-ocagent/src/adapters.ts

@@ -157,7 +157,8 @@ const adaptMessageEventType = (value: string): opencensus.proto.trace.v1.Span
  * @returns opencensus.proto.trace.v1.Span.TimeEvents
  */
 const adaptTimeEvents =
-    (annotations: Annotation[], messageEvents: MessageEvent[]):
+    (annotations: Annotation[], messageEvents: MessageEvent[],
+     droppedAnnotationsCount: number, droppedMessageEventsCount: number):
         opencensus.proto.trace.v1.Span.TimeEvents => {
       const timeEvents: opencensus.proto.trace.v1.Span.TimeEvent[] = [];
 
@@ -188,8 +189,8 @@ const adaptTimeEvents =
 
       return {
         timeEvent: timeEvents,
-        droppedAnnotationsCount: null,
-        droppedMessageEventsCount: null
+        droppedAnnotationsCount,
+        droppedMessageEventsCount
       };
     };
 
@@ -274,7 +275,9 @@ export const adaptSpan = (span: Span): opencensus.proto.trace.v1.Span => {
     endTime: millisToTimestamp(span.endTime),
     attributes: adaptAttributes(span.attributes, span.droppedAttributesCount),
     stackTrace: null,  // Unsupported by nodejs
-    timeEvents: adaptTimeEvents(span.annotations, span.messageEvents),
+    timeEvents: adaptTimeEvents(
+        span.annotations, span.messageEvents, span.droppedAnnotationsCount,
+        span.droppedMessageEventsCount),
     links: adaptLinks(span.links, span.droppedLinksCount),
     status: span.status,
     sameProcessAsParentSpan: adaptBoolean(!span.remoteParent),

packages/opencensus-exporter-ocagent/test/test-ocagent.ts

@@ -175,7 +175,12 @@ describe('OpenCensus Agent Exporter', () => {
     tracing = nodeTracing.start({
       exporter: ocAgentExporter,
       samplingRate: INITIAL_SAMPLER_PROBABILITY,
-      traceParams: {numberOfAttributesPerSpan: 4, numberOfLinksPerSpan: 3}
+      traceParams: {
+        numberOfAttributesPerSpan: 4,
+        numberOfLinksPerSpan: 3,
+        numberOfAnnontationEventsPerSpan: 2,
+        numberOfMessageEventsPerSpan: 3
+      }
     });
   });
 
@@ -344,9 +349,16 @@ describe('OpenCensus Agent Exporter', () => {
       // Annotation
       rootSpan.addAnnotation(
           'my_annotation', {myString: 'bar', myNumber: 123, myBoolean: true});
+      rootSpan.addAnnotation(
+          'my_annotation1', {myString: 'bar1', myNumber: 456, myBoolean: true});
+      rootSpan.addAnnotation(
+          'my_annotation2', {myString: 'bar2', myNumber: 789, myBoolean: true});
+      rootSpan.addAnnotation(
+          'my_annotation3', {myString: 'bar3', myNumber: 789, myBoolean: true});
 
       // Message Event
       const timeStamp = 123456789;
+      rootSpan.addMessageEvent('MessageEventTypeSent', 'aaaa', timeStamp);
       rootSpan.addMessageEvent('MessageEventTypeSent', 'ffff', timeStamp);
       rootSpan.addMessageEvent('MessageEventTypeRecv', 'ffff', timeStamp);
       // Use of `null` is to force a `TYPE_UNSPECIFIED` value
@@ -420,27 +432,46 @@ describe('OpenCensus Agent Exporter', () => {
 
             // Time Events
             assert.deepEqual(span.timeEvents, {
-              droppedAnnotationsCount: 0,
-              droppedMessageEventsCount: 0,
+              droppedAnnotationsCount: 2,
+              droppedMessageEventsCount: 1,
               timeEvent: [
                 {
                   value: 'annotation',
                   time: null,
                   annotation: {
                     description:
-                        {value: 'my_annotation', truncatedByteCount: 0},
+                        {value: 'my_annotation2', truncatedByteCount: 0},
                     attributes: {
                       attributeMap: {
                         myString: {
                           value: 'stringValue',
-                          stringValue: {value: 'bar', truncatedByteCount: 0}
+                          stringValue: {value: 'bar2', truncatedByteCount: 0}
                         },
-                        myNumber: {value: 'intValue', intValue: '123'},
+                        myNumber: {value: 'intValue', intValue: '789'},
                         myBoolean: {value: 'boolValue', boolValue: true}
                       },
                       droppedAttributesCount: 0
                     }
-                  }
+                  },
+                },
+                {
+                  value: 'annotation',
+                  time: null,
+                  annotation: {
+                    description:
+                        {value: 'my_annotation3', truncatedByteCount: 0},
+                    attributes: {
+                      attributeMap: {
+                        myString: {
+                          value: 'stringValue',
+                          stringValue: {value: 'bar3', truncatedByteCount: 0}
+                        },
+                        myNumber: {value: 'intValue', intValue: '789'},
+                        myBoolean: {value: 'boolValue', boolValue: true}
+                      },
+                      droppedAttributesCount: 0
+                    }
+                  },
                 },
                 {
                   messageEvent: {