From 92d8647962b7155721c8e6bc8cdaa2b1bfc9a77d Mon Sep 17 00:00:00 2001
From: Aksel Allas <allasaksel@gmail.com>
Date: Tue, 1 Oct 2024 16:08:45 +0300
Subject: [PATCH] feat(add-option-to-disable-instrumentation-http-metrics

---
 experimental/CHANGELOG.md                     |  1 +
 .../README.md                                 |  1 +
 .../src/http.ts                               |  6 +-
 .../src/types.ts                              |  2 +
 .../functionals/http-metrics-disabled.test.ts | 78 +++++++++++++++++++
 5 files changed, 86 insertions(+), 2 deletions(-)
 create mode 100644 experimental/packages/opentelemetry-instrumentation-http/test/functionals/http-metrics-disabled.test.ts

diff --git a/experimental/CHANGELOG.md b/experimental/CHANGELOG.md
index 04ea9a97b3a..a158b0a8e31 100644
--- a/experimental/CHANGELOG.md
+++ b/experimental/CHANGELOG.md
@@ -14,6 +14,7 @@ All notable changes to experimental packages in this project will be documented
   * Applies to both client and server spans
   * Generate spans compliant with Semantic Conventions 1.27+ when `OTEL_SEMCONV_STABILITY_OPT_IN` contains `http` or `http/dup`
   * Generate spans backwards compatible with previous attributes when `OTEL_SEMCONV_STABILITY_OPT_IN` contains `http/dup` or DOES NOT contain `http`
+* feat(add-option-to-disable-instrumentation-http-metrics): Add option to disable instrumentation-http metrics such as incoming/outgoing HTTP request duration [#4409](https://github.com/open-telemetry/opentelemetry-js/pull/5029) @AkselAllas
 
 ### :bug: (Bug Fix)
 
diff --git a/experimental/packages/opentelemetry-instrumentation-http/README.md b/experimental/packages/opentelemetry-instrumentation-http/README.md
index 456d5b34738..e934f082591 100644
--- a/experimental/packages/opentelemetry-instrumentation-http/README.md
+++ b/experimental/packages/opentelemetry-instrumentation-http/README.md
@@ -63,6 +63,7 @@ Http instrumentation has few options available to choose from. You can set the f
 | `ignoreOutgoingRequestHook` | `IgnoreOutgoingRequestFunction` | Http instrumentation will not trace all outgoing requests that matched with custom function |
 | `disableOutgoingRequestInstrumentation` | `boolean` | Set to true to avoid instrumenting outgoing requests at all. This can be helpful when another instrumentation handles outgoing requests. |
 | `disableIncomingRequestInstrumentation` | `boolean` | Set to true to avoid instrumenting incoming requests at all. This can be helpful when another instrumentation handles incoming requests. |
+| `disableMetrics` | `boolean` | Set to true in order to disable instrumentation-http from emitting any metrics such as duration of inbound/outbound HTTP requests. |
 | [`serverName`](https://github.com/open-telemetry/opentelemetry-js/blob/main/experimental/packages/opentelemetry-instrumentation-http/src/types.ts#L101) | `string` | The primary server name of the matched virtual host. |
 | [`requireParentforOutgoingSpans`](https://github.com/open-telemetry/opentelemetry-js/blob/main/experimental/packages/opentelemetry-instrumentation-http/src/types.ts#L103) | Boolean | Require that is a parent span to create new span for outgoing requests. |
 | [`requireParentforIncomingSpans`](https://github.com/open-telemetry/opentelemetry-js/blob/main/experimental/packages/opentelemetry-instrumentation-http/src/types.ts#L105) | Boolean | Require that is a parent span to create new span for incoming requests. |
diff --git a/experimental/packages/opentelemetry-instrumentation-http/src/http.ts b/experimental/packages/opentelemetry-instrumentation-http/src/http.ts
index 456b8d08e0c..b2af51ff8ed 100644
--- a/experimental/packages/opentelemetry-instrumentation-http/src/http.ts
+++ b/experimental/packages/opentelemetry-instrumentation-http/src/http.ts
@@ -88,6 +88,7 @@ export class HttpInstrumentation extends InstrumentationBase<HttpInstrumentation
   /** keep track on spans not ended */
   private readonly _spanNotEnded: WeakSet<Span> = new WeakSet<Span>();
   private _headerCapture;
+  private _disableMetrics: boolean;
   private _httpServerDurationHistogram!: Histogram;
   private _httpClientDurationHistogram!: Histogram;
 
@@ -96,6 +97,7 @@ export class HttpInstrumentation extends InstrumentationBase<HttpInstrumentation
   constructor(config: HttpInstrumentationConfig = {}) {
     super('@opentelemetry/instrumentation-http', VERSION, config);
     this._headerCapture = this._createHeaderCapture();
+    this._disableMetrics = this.getConfig().disableMetrics || false
 
     for (const entry in getEnv().OTEL_SEMCONV_STABILITY_OPT_IN) {
       if (entry.toLowerCase() === 'http/dup') {
@@ -851,9 +853,9 @@ export class HttpInstrumentation extends InstrumentationBase<HttpInstrumentation
 
     // Record metrics
     const duration = hrTimeToMilliseconds(hrTimeDuration(startTime, hrTime()));
-    if (spanKind === SpanKind.SERVER) {
+    if (spanKind === SpanKind.SERVER && !this._disableMetrics) {
       this._httpServerDurationHistogram.record(duration, metricAttributes);
-    } else if (spanKind === SpanKind.CLIENT) {
+    } else if (spanKind === SpanKind.CLIENT && !this._disableMetrics) {
       this._httpClientDurationHistogram.record(duration, metricAttributes);
     }
   }
diff --git a/experimental/packages/opentelemetry-instrumentation-http/src/types.ts b/experimental/packages/opentelemetry-instrumentation-http/src/types.ts
index 19647fcb49a..888376e18a9 100644
--- a/experimental/packages/opentelemetry-instrumentation-http/src/types.ts
+++ b/experimental/packages/opentelemetry-instrumentation-http/src/types.ts
@@ -102,6 +102,8 @@ export interface HttpInstrumentationConfig extends InstrumentationConfig {
   disableIncomingRequestInstrumentation?: boolean;
   /** If set to true, outgoing requests will not be instrumented at all. */
   disableOutgoingRequestInstrumentation?: boolean;
+  /** If set to true, no metrics will be emitted */
+  disableMetrics?: boolean;
   /** Function for adding custom attributes after response is handled */
   applyCustomAttributesOnSpan?: HttpCustomAttributeFunction;
   /** Function for adding custom attributes before request is handled */
diff --git a/experimental/packages/opentelemetry-instrumentation-http/test/functionals/http-metrics-disabled.test.ts b/experimental/packages/opentelemetry-instrumentation-http/test/functionals/http-metrics-disabled.test.ts
new file mode 100644
index 00000000000..fa3a2e6b550
--- /dev/null
+++ b/experimental/packages/opentelemetry-instrumentation-http/test/functionals/http-metrics-disabled.test.ts
@@ -0,0 +1,78 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import {
+  AggregationTemporality,
+  InMemoryMetricExporter,
+  MeterProvider,
+} from '@opentelemetry/sdk-metrics';
+import { NodeTracerProvider } from '@opentelemetry/sdk-trace-node';
+import * as assert from 'assert';
+import { HttpInstrumentation } from '../../src/http';
+import { httpRequest } from '../utils/httpRequest';
+import { TestMetricReader } from '../utils/TestMetricReader';
+
+const instrumentation = new HttpInstrumentation({disableMetrics:true});
+instrumentation.enable();
+instrumentation.disable();
+
+import * as http from 'http';
+
+let server: http.Server;
+const serverPort = 22346;
+const protocol = 'http';
+const hostname = 'localhost';
+const pathname = '/test';
+const tracerProvider = new NodeTracerProvider();
+const metricsMemoryExporter = new InMemoryMetricExporter(
+  AggregationTemporality.DELTA
+);
+const metricReader = new TestMetricReader(metricsMemoryExporter);
+const meterProvider = new MeterProvider({ readers: [metricReader] });
+
+instrumentation.setTracerProvider(tracerProvider);
+instrumentation.setMeterProvider(meterProvider);
+
+describe('metrics can be disabled', () => {
+  beforeEach(() => {
+    metricsMemoryExporter.reset();
+  });
+
+  before(() => {
+    instrumentation.enable();
+    server = http.createServer((request, response) => {
+      response.end('Test Server Response');
+    });
+    server.listen(serverPort);
+  });
+
+  after(() => {
+    server.close();
+    instrumentation.disable();
+  });
+
+  it('should not create server/client duration metrics', async () => {
+    const requestCount = 3;
+    for (let i = 0; i < requestCount; i++) {
+      await httpRequest.get(
+        `${protocol}://${hostname}:${serverPort}${pathname}`
+      );
+    }
+    await metricReader.collectAndExport();
+    const resourceMetrics = metricsMemoryExporter.getMetrics();
+    const scopeMetrics = resourceMetrics[0].scopeMetrics;
+    assert.strictEqual(scopeMetrics.length, 0, 'scopeMetrics count');
+  });
+});