Confusing message on Http timeout

[danmoseley]

From some test failures I noticed:

NuGet.Protocol.Core.Types.FatalProtocolException : An error occurred while retrieving package metadata for 'Microsoft.NETFramework.ReferenceAssemblies.net48.1.0.2' from source 'dotnet-public'.
---- System.Threading.Tasks.TaskCanceledException : The request was canceled due to the configured HttpClient.Timeout of -0.001 seconds elapsing.
-------- System.TimeoutException : The operation was canceled.
------------ System.Threading.Tasks.TaskCanceledException : The operation was canceled.
---------------- System.TimeoutException : A connection could not be established within the configured ConnectTimeout.

Apparently the timeout was set to Timeout.InfiniteTimeSpan, which is -1 ms. Presumably this couldn't have expired, so the message is confusing. I don't have a repro, so feel free to close if it's not important.

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Issue Details

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From some test failures I noticed:

NuGet.Protocol.Core.Types.FatalProtocolException : An error occurred while retrieving package metadata for 'Microsoft.NETFramework.ReferenceAssemblies.net48.1.0.2' from source 'dotnet-public'.
---- System.Threading.Tasks.TaskCanceledException : The request was canceled due to the configured HttpClient.Timeout of -0.001 seconds elapsing.
-------- System.TimeoutException : The operation was canceled.
------------ System.Threading.Tasks.TaskCanceledException : The operation was canceled.
---------------- System.TimeoutException : A connection could not be established within the configured ConnectTimeout.

Apparently the timeout was set to Timeout.InfiniteTimeSpan, which is -1 ms. Presumably this couldn't have expired, so the message is confusing. I don't have a repro, so feel free to close if it's not important.

Author:	danmoseley
Assignees:	-
Labels:	area-System.Net.Http
Milestone:	-

[danmoseley]

#67508

[MihaZupan]

The relevant code path that determines the exception type:

runtime/src/libraries/System.Net.Http/src/System/Net/Http/HttpClient.cs

Lines 607 to 609 in 1c2198e

	// If this exception is for cancellation, but cancellation wasn't requested, either by the caller's token or by the pending requests source,
	// the only other cause could be a timeout. Treat it as such.
	e = toThrow = new TaskCanceledException(SR.Format(SR.net_http_request_timedout, _timeout.TotalSeconds), new TimeoutException(e.Message, e), oce.CancellationToken);

We should differentiate between a regular timeout and the ConnectTimeout.

Ideally, we would also expose such info in a programmatical way to the user. This recently came up in YARP as well (dotnet/yarp#1628).

[karelz]

Triage: It seems we are doing the right thing in the ConnectionPool, but HttpClient overrides it (and wraps with TImeoutException even if the timeout is not set) -- we should fix that.