fix: enforce consistent span durations

CHANGELOG.md

@@ -12,6 +12,8 @@ All notable changes to this project will be documented in this file.
 
 ### :bug: (Bug Fix)
 
+* fix(sdk-trace): enforce consistent span durations
+  [#3327](https://github.com/open-telemetry/opentelemetry-js/pull/3327) @dyladan
 * fix(resources): fix EnvDetector throwing errors when attribute values contain spaces
   [#3295](https://github.com/open-telemetry/opentelemetry-js/issues/3295)
 

packages/opentelemetry-sdk-trace-base/src/Span.ts

@@ -15,7 +15,7 @@
  */
 
 import * as api from '@opentelemetry/api';
-import { Context, SpanAttributeValue } from '@opentelemetry/api';
+import { Context, HrTime, SpanAttributeValue } from '@opentelemetry/api';
 import {
   Clock,
   hrTimeDuration,
@@ -191,10 +191,12 @@ export class Span implements api.Span, ReadableSpan {
 
     if (this._duration[0] < 0) {
       api.diag.warn(
-        'Inconsistent start and end time, startTime > endTime',
+        'Inconsistent start and end time, startTime > endTime. Setting span duration to 0ms.',
         this.startTime,
         this.endTime
       );
+      this.endTime = this.startTime.slice() as HrTime;
+      this._duration = [0, 0];
     }
 
     this._spanProcessor.onEnd(this);

packages/opentelemetry-sdk-trace-base/test/common/Span.test.ts

@@ -128,6 +128,18 @@ describe('Span', () => {
     assert.ok(hrTimeToNanoseconds(span.duration) >= 0);
   });
 
+  it('should ensure duration is never negative even if provided with inconsistent times', () => {
+    const span = new Span(
+      tracer,
+      ROOT_CONTEXT,
+      name,
+      spanContext,
+      SpanKind.SERVER
+    );
+    span.end(hrTimeToMilliseconds(span.startTime) - 1);
+    assert.ok(hrTimeToNanoseconds(span.duration) >= 0);
+  });
+
   it('should have valid event.time', () => {
     const span = new Span(
       tracer,