feat(tracing): Add experiment to capture http timings

packages/browser-integration-tests/suites/tracing/browsertracing/http-timings/init.js

@@ -0,0 +1,17 @@
+import * as Sentry from '@sentry/browser';
+import { Integrations } from '@sentry/tracing';
+
+window.Sentry = Sentry;
+
+Sentry.init({
+  dsn: 'https://[email protected]/1337',
+  integrations: [
+    new Integrations.BrowserTracing({
+      idleTimeout: 1000,
+      _experiments: {
+        enableHTTPTimings: true,
+      },
+    }),
+  ],
+  tracesSampleRate: 1,
+});

packages/browser-integration-tests/suites/tracing/browsertracing/http-timings/subject.js

@@ -0,0 +1 @@
+fetch('http://example.com/0').then(fetch('http://example.com/1').then(fetch('http://example.com/2')));

packages/browser-integration-tests/suites/tracing/browsertracing/http-timings/test.ts

@@ -0,0 +1,47 @@
+import { expect } from '@playwright/test';
+import type { Event } from '@sentry/types';
+
+import { sentryTest } from '../../../../utils/fixtures';
+import { getMultipleSentryEnvelopeRequests, shouldSkipTracingTest } from '../../../../utils/helpers';
+
+sentryTest('should create fetch spans with http timing', async ({ getLocalTestPath, page }) => {
+  if (shouldSkipTracingTest()) {
+    sentryTest.skip();
+  }
+  await page.route('https://example.com/*', async route => {
+    const request = route.request();
+    const postData = await request.postDataJSON();
+
+    await route.fulfill({
+      status: 200,
+      contentType: 'application/json',
+      body: JSON.stringify(Object.assign({ id: 1 }, postData)),
+    });
+  });
+
+  const url = await getLocalTestPath({ testDir: __dirname });
+
+  const envelopes = await getMultipleSentryEnvelopeRequests<Event>(page, 2, { url, timeout: 10000 });
+  const tracingEvent = envelopes[envelopes.length - 1]; // last envelope contains tracing data on all browsers
+
+  const requestSpans = tracingEvent.spans?.filter(({ op }) => op === 'http.client');
+
+  expect(requestSpans).toHaveLength(3);
+
+  requestSpans?.forEach((span, index) =>
+    expect(span).toMatchObject({
+      description: `GET http://example.com/${index}`,
+      parent_span_id: tracingEvent.contexts?.trace?.span_id,
+      span_id: expect.any(String),
+      start_timestamp: expect.any(Number),
+      timestamp: expect.any(Number),
+      trace_id: tracingEvent.contexts?.trace?.trace_id,
+      data: expect.objectContaining({
+        'http.client.connectStart': expect.any(Number),
+        'http.client.requestStart': expect.any(Number),
+        'http.client.responseStart': expect.any(Number),
+        'network.protocol.version': expect.any(String),
+      }),
+    }),
+  );
+});

packages/tracing-internal/src/browser/browsertracing.ts

@@ -111,6 +111,7 @@ export interface BrowserTracingOptions extends RequestInstrumentationOptions {
   _experiments: Partial<{
     enableLongTask: boolean;
     enableInteractions: boolean;
+    enableHTTPTimings: boolean;
     onStartRouteTransaction: (t: Transaction | undefined, ctx: TransactionContext, getCurrentHub: () => Hub) => void;
   }>;
 
@@ -145,7 +146,6 @@ const DEFAULT_BROWSER_TRACING_OPTIONS: BrowserTracingOptions = {
   startTransactionOnLocationChange: true,
   startTransactionOnPageLoad: true,
   enableLongTask: true,
-  _experiments: {},
   ...defaultRequestInstrumentationOptions,
 };
 
@@ -253,6 +253,9 @@ export class BrowserTracing implements Integration {
       traceXHR,
       tracePropagationTargets,
       shouldCreateSpanForRequest,
+      _experiments: {
+        enableHTTPTimings: _experiments.enableHTTPTimings,
+      },
     });
   }
 

packages/tracing-internal/src/browser/request.ts

@@ -4,6 +4,7 @@ import type { DynamicSamplingContext, Span } from '@sentry/types';
 import {
   addInstrumentationHandler,
   BAGGAGE_HEADER_NAME,
+  browserPerformanceTimeOrigin,
   dynamicSamplingContextToSentryBaggageHeader,
   isInstanceOf,
   SENTRY_XHR_DATA_KEY,
@@ -14,6 +15,13 @@ export const DEFAULT_TRACE_PROPAGATION_TARGETS = ['localhost', /^\/(?!\/)/];
 
 /** Options for Request Instrumentation */
 export interface RequestInstrumentationOptions {
+  /**
+   * Allow experiments for the request instrumentation.
+   */
+  _experiments: Partial<{
+    enableHTTPTimings: boolean;
+  }>;
+
   /**
    * @deprecated Will be removed in v8.
    * Use `shouldCreateSpanForRequest` to control span creation and `tracePropagationTargets` to control
@@ -108,12 +116,13 @@ export const defaultRequestInstrumentationOptions: RequestInstrumentationOptions
   // TODO (v8): Remove this property
   tracingOrigins: DEFAULT_TRACE_PROPAGATION_TARGETS,
   tracePropagationTargets: DEFAULT_TRACE_PROPAGATION_TARGETS,
+  _experiments: {},
 };
 
 /** Registers span creators for xhr and fetch requests  */
 export function instrumentOutgoingRequests(_options?: Partial<RequestInstrumentationOptions>): void {
   // eslint-disable-next-line deprecation/deprecation
-  const { traceFetch, traceXHR, tracePropagationTargets, tracingOrigins, shouldCreateSpanForRequest } = {
+  const { traceFetch, traceXHR, tracePropagationTargets, tracingOrigins, shouldCreateSpanForRequest, _experiments } = {
     traceFetch: defaultRequestInstrumentationOptions.traceFetch,
     traceXHR: defaultRequestInstrumentationOptions.traceXHR,
     ..._options,
@@ -132,17 +141,58 @@ export function instrumentOutgoingRequests(_options?: Partial<RequestInstrumenta
 
   if (traceFetch) {
     addInstrumentationHandler('fetch', (handlerData: FetchData) => {
-      fetchCallback(handlerData, shouldCreateSpan, shouldAttachHeadersWithTargets, spans);
+      const createdSpan = fetchCallback(handlerData, shouldCreateSpan, shouldAttachHeadersWithTargets, spans);
+      if (_experiments?.enableHTTPTimings && createdSpan) {
+        addHTTPTimings(createdSpan);
+      }
     });
   }
 
   if (traceXHR) {
     addInstrumentationHandler('xhr', (handlerData: XHRData) => {
-      xhrCallback(handlerData, shouldCreateSpan, shouldAttachHeadersWithTargets, spans);
+      const createdSpan = xhrCallback(handlerData, shouldCreateSpan, shouldAttachHeadersWithTargets, spans);
+      if (_experiments?.enableHTTPTimings && createdSpan) {
+        addHTTPTimings(createdSpan);
+      }
     });
   }
 }
 
+/**
+ * Creates a temporary observer to listen to the next fetch/xhr resourcing timings,
+ * so that when timings hit their per-browser limit they don't need to be removed.
+ *
+ * @param span A span that has yet to be finished, must contain `url` on data.
+ */
+function addHTTPTimings(span: Span): void {
+  const url = span.data.url;
+  const observer = new PerformanceObserver(list => {
+    const entries = list.getEntries() as PerformanceResourceTiming[];
+    entries.forEach(entry => {
+      if ((entry.initiatorType === 'fetch' || entry.initiatorType === 'xmlhttprequest') && entry.name.endsWith(url)) {
+        const spanData = resourceTimingEntryToSpanData(entry);
+        spanData.forEach(data => span.setData(...data));
+        observer.disconnect();
+      }
+    });
+  });
+  observer.observe({
+    entryTypes: ['resource'],
+  });
+}
+
+function resourceTimingEntryToSpanData(resourceTiming: PerformanceResourceTiming): [string, string | number][] {
+  if (!browserPerformanceTimeOrigin) {
+    return [['network.protocol.version', resourceTiming.nextHopProtocol]];
+  }
+  return [
+    ['network.protocol.version', resourceTiming.nextHopProtocol],
+    ['http.client.connectStart', (browserPerformanceTimeOrigin + resourceTiming.connectStart) / 1000],
+    ['http.client.requestStart', (browserPerformanceTimeOrigin + resourceTiming.requestStart) / 1000],
+    ['http.client.responseStart', (browserPerformanceTimeOrigin + resourceTiming.responseStart) / 1000],
+  ];
+}
+
 /**
  * A function that determines whether to attach tracing headers to a request.
  * This was extracted from `instrumentOutgoingRequests` to make it easier to test shouldAttachHeaders.
@@ -154,13 +204,15 @@ export function shouldAttachHeaders(url: string, tracePropagationTargets: (strin
 
 /**
  * Create and track fetch request spans
+ *
+ * @returns Span if a span was created, otherwise void.
  */
-export function fetchCallback(
+function fetchCallback(
   handlerData: FetchData,
   shouldCreateSpan: (url: string) => boolean,
   shouldAttachHeaders: (url: string) => boolean,
   spans: Record<string, Span>,
-): void {
+): Span | void {
   if (!hasTracingEnabled() || !(handlerData.fetchData && shouldCreateSpan(handlerData.fetchData.url))) {
     return;
   }
@@ -230,6 +282,7 @@ export function fetchCallback(
         options,
       );
     }
+    return span;
   }
 }
 
@@ -302,13 +355,15 @@ export function addTracingHeadersToFetchRequest(
 
 /**
  * Create and track xhr request spans
+ *
+ * @returns Span if a span was created, otherwise void.
  */
-export function xhrCallback(
+function xhrCallback(
   handlerData: XHRData,
   shouldCreateSpan: (url: string) => boolean,
   shouldAttachHeaders: (url: string) => boolean,
   spans: Record<string, Span>,
-): void {
+): Span | void {
   const xhr = handlerData.xhr;
   const sentryXhrData = xhr && xhr[SENTRY_XHR_DATA_KEY];
 
@@ -372,5 +427,7 @@ export function xhrCallback(
         // Error: InvalidStateError: Failed to execute 'setRequestHeader' on 'XMLHttpRequest': The object's state must be OPENED.
       }
     }
+
+    return span;
   }
 }