Don't wait for control stream before processing requests#65399
Merged
BrennanConroy merged 2 commits intomainfrom Mar 11, 2026
Merged
Don't wait for control stream before processing requests#65399BrennanConroy merged 2 commits intomainfrom
BrennanConroy merged 2 commits intomainfrom
Conversation
BrennanConroy
added
feature-kestrel
area-networking
Contributor
There was a problem hiding this comment.
Pull request overview
This PR updates Kestrel's HTTP/3 implementation to start processing incoming requests immediately without waiting for the outbound control stream to be created and SETTINGS to be sent. This change aligns with RFC 9114 section 7.2.4.2, which implies that requests can be processed before the SETTINGS frame is received, and matches HttpClient's existing behavior.
Changes:
- Move outbound control stream creation to a background task that runs concurrently with request processing
- Add comprehensive test coverage for scenarios where the control stream is blocked or never accepted by the client
- Add error handling for control stream failures during cleanup to prevent hangs during graceful shutdown
Reviewed changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| src/Servers/Kestrel/Core/src/Internal/Http3/Http3Connection.cs | Changed control stream initialization to run asynchronously in background without blocking request processing; moved error handling to cleanup phase |
| src/Servers/Kestrel/test/InMemory.FunctionalTests/Http3/Http3ConnectionTests.cs | Added three unit tests covering blocked control stream scenarios: request processing, graceful shutdown, and abort |
| src/Servers/Kestrel/test/Interop.FunctionalTests/Http3/Http3RequestTests.cs | Added two functional tests using real QUIC connections to verify graceful shutdown works when client never accepts server's control stream |
| src/Servers/Kestrel/test/Interop.FunctionalTests/Interop.FunctionalTests.csproj | Added reference to VariableLengthIntegerHelper for HTTP/3 frame encoding in tests |
dotnet-policy-service
Bot
added
the
pending-ci-rerun
DeagleGross
approved these changes
Feb 23, 2026
| return new Http3ControlStream<TContext>(application, httpConnectionContext, 0L); | ||
| OutboundControlStream = new Http3ControlStream<TContext>(application, httpConnectionContext, 0L); | ||
|
|
||
| // Don't delay on waiting to send outbound control stream settings. |
Member
There was a problem hiding this comment.
irrelevant comment? Was it "dont delay" because it was not an awaited task?
Member
Author
There was a problem hiding this comment.
Yeah, should probably remove this and add a comment where we call CreateNewUnidirectionalStreamAsync
This was referenced Feb 25, 2026
Open
Member
Author
|
/azp run |
dotnet-policy-service
Bot
removed
the
pending-ci-rerun
|
Azure Pipelines successfully started running 3 pipeline(s). |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
HTTP/3 RFC implies requests can be processed before the SETTINGS frame is processed.
https://datatracker.ietf.org/doc/html/rfc9114#section-7.2.4.2
HttpClient is also already sending SETTINGS in a background task while starting the rest of it's processing: https://source.dot.net/#System.Net.Http/System/Net/Http/SocketsHttpHandler/[Http3Connection.cs](https://source.dot.net/#System.Net.Http/System/Net/Http/SocketsHttpHandler/Http3Connection.cs,103),103
This PR updates Kestrel to start the control stream and SETTINGS sending in a background thread and start processing incoming requests immediately.