Add HTTP request latency log enricher (experimental) by EasyL0ver · Pull Request #7602 · dotnet/extensions

EasyL0ver · 2026-07-01T08:42:26Z

Summary

Completes the open-sourcing of the incoming-request latency log enricher that was originally intended for public release but was orphaned. Migrates it from the R9 SDK into Microsoft.AspNetCore.Diagnostics.Middleware.

Changes

Public API: AddHttpLatencyTelemetry() extension method (registered via AddHttpLogEnricher) in Microsoft.Extensions.DependencyInjection namespace.
Internal: HttpLatencyLogEnricher reads ILatencyContext from request services and emits a latencyInfo tag with checkpoints, measures, tags, and total duration.
API status: Marked [Experimental(EXTEXP0013)] on both class and method, consistent with precedent (sibling HttpClientLatencyLogEnricher).

Design notes

Tag-key casing: uses lowercase latencyInfo, while sibling client enricher uses uppercase LatencyInfo. This inconsistency should be addressed at API review.

Precedent

Follows the pattern established by @rainsxng (#6783) and @mariamgerges (#7380) for other migration enrichers. Baseline JSON, attribute placement, test porting all consistent with that precedent.

Microsoft Reviewers: Open in CodeFlow

Migrates the incoming-request latency log enricher from the R9 SDK into Microsoft.AspNetCore.Diagnostics.Middleware. Adds the public AddHttpLatencyTelemetry() extension (registered via AddHttpLogEnricher) and the internal HttpLatencyLogEnricher that emits a latencyInfo tag with checkpoints, measures, tags and total duration on incoming HTTP request logs. The new API ships behind [Experimental] (EXTEXP0013) on both the class and the method, mirroring the sibling HttpClientLatency enricher. Tests are faithfully ported from the R9 suite (golden-string serialization plus null/edge cases). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Removes PerfPanel branding from MockLatencyData helper class and renames the property to better reflect its purpose as serialized latency data. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The MockLatencyData class was nested in HttpLatencyLogEnricherTests. Extract it to a dedicated file following extensions repo convention (e.g., CustomHttpLogEnricher.cs, TestHttpLogEnricher.cs) for better test organization. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Adds an incoming HTTP request latency log enricher to Microsoft.AspNetCore.Diagnostics.Middleware, exposing a new experimental DI extension (AddHttpLatencyTelemetry) and wiring up serialization of ILatencyContext.LatencyData into HTTP log enrichment output.

Changes:

Introduces AddHttpLatencyTelemetry() (experimental) to register the incoming-request latency log enricher.
Adds HttpLatencyLogEnricher that reads ILatencyContext from request services and emits a serialized latency payload.
Ports/creates tests and updates the library README and API baseline JSON.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
test/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware.Tests/Latency/Internal/MockLatencyData.cs	Adds a test helper that builds deterministic `LatencyData` + expected serialized string.
test/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware.Tests/Latency/Internal/HttpLatencyLogEnricherTests.cs	Adds unit tests for the new incoming-request log enricher behavior.
test/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware.Tests/Latency/HttpLatencyTelemetryExtensionsTests.cs	Adds DI registration tests for `AddHttpLatencyTelemetry`.
src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/README.md	Documents how to register the new enricher.
src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Microsoft.AspNetCore.Diagnostics.Middleware.json	Adds the new experimental public API to the baseline.
src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Latency/Internal/HttpLatencyLogEnricher.cs	Implements the incoming-request latency enrichment + serialization format.
src/Libraries/Microsoft.AspNetCore.Diagnostics.Middleware/Latency/HttpLatencyTelemetryExtensions.cs	Adds the experimental DI extension method for registering the enricher.

System.Globalization and System.Linq became unnecessary when MockLatencyData was extracted to a separate file. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

EasyL0ver · 2026-07-08T09:03:29Z

@dotnet-policy-service agree company="Microsoft"

EasyL0ver · 2026-07-08T09:04:56Z

@dotnet-policy-service agree company="Microsoft"

EasyL0ver · 2026-07-08T09:34:47Z

Thanks — noted the automated suggestions. These behaviors were intentionally preserved to maintain parity with the original production implementation:

StringBuilder pool: uses the factory-created pool pattern to match production behavior.
Header serialization: header StringValues are appended as-is to preserve the existing log schema.
Null behaviour: tests/assertions mirror the original implementation (NullReferenceException on null context).
Tag key casing: kept "latencyInfo" to avoid changing the log schema; recommend API review to standardize if desired.

If maintainers prefer these changes, I can follow up with a targeted PR. Parity diffs can be provided on request (internal review only).

…ant AddHttpLoggingRedaction() from example Make test helper properties get-only to communicate immutability. Remove redundant AddHttpLoggingRedaction() from README example because AddHttpLatencyTelemetry already wires the logging plumbing. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Rename the incoming enricher's log dimension key from lowercase 'latencyInfo' to 'LatencyInfo' to match the logging-dimension naming convention established in dotnet#4545 and used by the sibling HttpClientLatencyLogEnricher. Updated test assertions accordingly. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

- Use PoolFactory.SharedStringBuilderPool (static) instead of a per-instance pool. - Append only the first client-application header value instead of the whole StringValues. Both match the established pattern in the sibling outgoing-request enricher. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The null-context and without-latency-context tests set up HeaderDictionary and HttpRequest mocks that were never exercised. Remove the dead setup for clarity. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

dotnet-comment-bot · 2026-07-08T17:02:39Z

‼️ Found issues ‼️

Project	Coverage Type	Expected	Actual
Microsoft.Extensions.Diagnostics.Testing	Line	99	98.65 🔻
Microsoft.Extensions.Telemetry	Line	93	91.95 🔻
Microsoft.Extensions.AI	Line	89	88.62 🔻
Microsoft.Extensions.AI	Branch	89	88.57 🔻
Microsoft.Extensions.AI.OpenAI	Line	75	62.89 🔻
Microsoft.Extensions.AI.OpenAI	Branch	75	50.41 🔻
Microsoft.Extensions.DataIngestion.MarkItDown	Line	75	4.46 🔻
Microsoft.Extensions.DataIngestion.MarkItDown	Branch	75	0 🔻
Microsoft.Extensions.Diagnostics.ResourceMonitoring	Line	99	96.03 🔻
Microsoft.Extensions.Diagnostics.ResourceMonitoring	Branch	99	94.39 🔻
Microsoft.Extensions.Diagnostics.ResourceMonitoring.Kubernetes	Line	99	97.73 🔻
Microsoft.Extensions.ServiceDiscovery.Dns	Line	75	71.61 🔻
Microsoft.Extensions.ServiceDiscovery.Abstractions	Line	75	42.11 🔻
Microsoft.Extensions.ServiceDiscovery.Abstractions	Branch	75	42.86 🔻
Microsoft.Extensions.ServiceDiscovery	Line	75	67.96 🔻
Microsoft.Extensions.ServiceDiscovery	Branch	75	71.43 🔻
Microsoft.Extensions.ServiceDiscovery.Yarp	Line	75	73.85 🔻
Microsoft.Extensions.ServiceDiscovery.Yarp	Branch	75	70 🔻
Microsoft.Extensions.VectorData.Abstractions	Line	75	37.39 🔻
Microsoft.Extensions.VectorData.Abstractions	Branch	75	22.73 🔻

🎉 Good job! The coverage increased 🎉
Update MinCodeCoverage in the project files.

Project	Expected	Actual
Microsoft.Gen.BuildMetadata	97	100
Microsoft.Gen.MetadataExtractor	57	73
Microsoft.Gen.MetricsReports	67	69
Microsoft.Extensions.AI.Abstractions	82	85
Microsoft.Extensions.AI.Evaluation.NLP	0	78
Microsoft.Extensions.Caching.Hybrid	82	84
Microsoft.Extensions.DataIngestion	75	89
Microsoft.Extensions.DataIngestion.Markdig	75	90
Microsoft.Extensions.Http.Resilience	97	100

Full code coverage report: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1499794&view=codecoverage-tab

evgenyfedorov2 · 2026-07-20T09:11:28Z

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#if NET8_0_OR_GREATER


why is it not going to work on .NET Framework?

evgenyfedorov2 · 2026-07-20T09:12:25Z

+/// Extensions for enriching incoming HTTP request logs with latency telemetry.
+/// </summary>
+[Experimental(diagnosticId: DiagnosticIds.Experiments.HttpLogging, UrlFormat = DiagnosticIds.UrlFormat)]
+public static class HttpLatencyTelemetryExtensions


Suggested change

public static class HttpLatencyTelemetryExtensions

public static class HttpLatencyTelemetryServiceCollectionExtensions

…uard (#7645) Rename HttpLatencyTelemetryExtensions and drop redundant TFM guard Address post-merge review feedback on #7602: - Rename HttpLatencyTelemetryExtensions to HttpLatencyTelemetryServiceCollectionExtensions to match the *ServiceCollectionExtensions naming convention used by sibling extension classes (RequestLatencyTelemetryServiceCollectionExtensions, HttpLoggingServiceCollectionExtensions). - Remove the always-true #if NET8_0_OR_GREATER guard from the enricher and its extensions. The project only targets net8.0+, so the guard never excluded any target framework. Copilot-Session: d705cd71-1bda-4572-88e7-0bbfda83c3d6 Co-authored-by: Pawel Kudlacik <pkudlacik@microsoft.com> Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

EasyL0ver requested a review from a team as a code owner July 1, 2026 08:42

dotnet-policy-service Bot assigned EasyL0ver Jul 1, 2026

Pawel Kudlacik and others added 2 commits July 1, 2026 11:21

Rename PerfPanel reference to SerializedLatencyData in test mock

3fda656

Removes PerfPanel branding from MockLatencyData helper class and renames the property to better reflect its purpose as serialized latency data. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

evgenyfedorov2 requested a review from Copilot July 2, 2026 14:13

Copilot started reviewing on behalf of evgenyfedorov2 July 2, 2026 14:14 View session

Copilot AI reviewed Jul 2, 2026

View reviewed changes

Remove unused usings from HttpLatencyLogEnricherTests

328d313

System.Globalization and System.Linq became unnecessary when MockLatencyData was extracted to a separate file. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Pawel Kudlacik and others added 4 commits July 8, 2026 11:44

mariamgerges approved these changes Jul 10, 2026

View reviewed changes

EasyL0ver merged commit b3a34f1 into dotnet:main Jul 15, 2026
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evgenyfedorov2 reviewed Jul 20, 2026

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EasyL0ver mentioned this pull request Jul 20, 2026

Rename HttpLatencyTelemetry extensions class and drop redundant TFM guard #7645

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Add HTTP request latency log enricher (experimental) - #7602

Add HTTP request latency log enricher (experimental)#7602
EasyL0ver merged 8 commits into
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EasyL0ver:users/pkudlacik/perfpanel-http-latency-enricher

EasyL0ver commented Jul 1, 2026 •

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	public static class HttpLatencyTelemetryExtensions
	public static class HttpLatencyTelemetryServiceCollectionExtensions

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Precedent

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EasyL0ver commented Jul 8, 2026

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EasyL0ver commented Jul 1, 2026 •

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