Warning after updating to 2.1.0

[marekott]

Describe the bug

After updating to 2.1.0 of Yarp.ReverseProxy we have suddenly started observing a lot of warnings logged for traffic forwarded to microservice using SignalR. For example:
UpgradeRequestClient: The client reported an error when copying the upgraded request body.
UpgradeResponseCanceled: Copying the upgraded response body was canceled.
RequestCanceled: The request was canceled before receiving a response.

Is it expected behavior after mentioned update? I've never observed such logs on previous version and there were no other changes that could explain it. If it is desired behavior (I can see there were some changes regarding logging: #2325) how should I understand above logs? Is there something to worry about?

[JohnCampionJr]

I am experiencing this too; is there any way to disable the warning?

[MihaZupan]

Was this specifically a change when going from 2.0 to 2.1, or did you see similar behavior in other versions as well?
Can you also please share the exceptions (including stack traces) associated with these errors? That will help us narrow down where failures are occurring.

There were some changes around how different error conditions are classified, but I don't believe it should have affected these categories.

Errors like RequestCanceled indicate that the client talking to the proxy went away before we were able to get a response from the backend destination. My expectation is that you should be seeing it at a similar rate in 2.0 or 2.1.

[JohnCampionJr]

I returned to v2.0.1 and the warning went away. There is definitely some sort of regression.

I'm using it in this project:
https://github.com/JohnCampionJr/AspNetCore.SpaYarp/tree/multispayarp

I'll see if I can provide the exceptions.

[JohnCampionJr]

Here's the exception, only seen in 2.1 and not in 2.0.1.

.net8.0, macOS if that helps.

warn: Yarp.ReverseProxy.Forwarder.HttpForwarder[48]
      UpgradeRequestCanceled: Copying the upgraded request body was canceled.
      System.IO.IOException: The client reset the request stream.
         at System.IO.Pipelines.Pipe.GetReadResult(ReadResult& result)
         at System.IO.Pipelines.Pipe.GetReadAsyncResult()
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2.Http2MessageBody.ReadAsync(CancellationToken cancellationToken)
         at System.Runtime.CompilerServices.PoolingAsyncValueTaskMethodBuilder`1.StateMachineBox`1.System.Threading.Tasks.Sources.IValueTaskSource<TResult>.GetResult(Int16 token)
         at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpRequestStream.ReadAsyncInternal(Memory`1 destination, CancellationToken cancellationToken)
         at System.Runtime.CompilerServices.PoolingAsyncValueTaskMethodBuilder`1.StateMachineBox`1.System.Threading.Tasks.Sources.IValueTaskSource<TResult>.GetResult(Int16 token)
         at Yarp.ReverseProxy.Forwarder.StreamCopier.CopyAsync(Stream input, Stream output, Int64 promisedContentLength, StreamCopierTelemetry telemetry, ActivityCancellationTokenSource activityToken, Boolean autoFlush, CancellationToken cancellation)

[MihaZupan]

Between 2.0.1 and 2.1.0, the log level of "ForwardingError" (event 48) was raised from Information to Warning (#2025).
It's possible the only difference after updating to 2.1.0 is that you're not silently ignoring these logs anymore.

If you lower the log level you observe for YARP to Information while running 2.0.1, do you see a comparable rate of errors?

[MihaZupan]

Have you had a chance to confirm whether this is the case for you?

[scottt13]

Same issue here, many warnings being logged for cancelled requests after upgrading to 2.1.0. We try to keep a fairly clean house in terms of warnings and errors and this is now flooding our warning logs with messages that we are not going to be able to do anything with because it is expected that some requests will be cancelled from time to time.

[MihaZupan]

Agreed on the cancelled requests being too noisy here.

Given that there is no indication that there is a regression here resulting in more errors, and only that the existing errors were raised from Info to Warn, I'm closing this as a duplicate of #2195 which deals with reducing the amount of noise from cancelled requests.

[plachor]

Hi @MihaZupan just to be sure I understand, you state that those 3 warnings mentioned by @marekott are logged due to request aborted by client and Yarp is simply logging them with warning where in fact are more like debug logs. So we can simply ignore those till you fix severity level.