Improve tracing of HTTP/2 PINGs

[antonfirsov]

#57617 can be a worrying reliability issue. In case there will be other reports, it is very important to have the ability to collect traces that can help hunting down a potential bug in HttpClient or Kestrel. Currently we are not logging received PING content at all, which prevents investigation based on customer data.

This is a minimal-risk (log only) addition to #54755, which I believe we should backport to 6.0 (including RC2, and maybe RC1 if it meets the bar).

Contributes to #57617.

[ghost]

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Issue Details

---

#57617 can be a worrying reliability issue. In case there will be other reports, it is very important to have the ability to collect traces that can help hunting down a potential bug in HttpClient or Kestrel. Currently we are not logging received PING content at all, which prevents investigation based on customer data.

This is a minimal-risk (log only) addition to #54755, which I believe we should backport to 6.0 (including RC2, and maybe RC1 if it can meet the bar).

Contributes to #57617.

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

[karelz]

@antonfirsov for 6.0 backport, can we somehow easily check that when the logging is enabled, nothing bad happens and/or that we get what we need? (e.g. with induced error)

[karelz]

CI failures: System.Threading.Tasks.Tests - known problem #57331, re-running tests

[antonfirsov]

I pushed a test improvement to make sure both failure cases (ThrowProtocolError() calls) are covered.

Did a local run of all flow control tests having an EventListener attached, and everything worked as expected.

[antonfirsov]

/azp run runtime-libraries-coreclr outerloop

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[antonfirsov]

Outerloop test failures are unrelated and likely external outages: #46439#41381

[antonfirsov]

/backport to release/6.0

[github-actions]

Started backporting to release/6.0: https://github.com/dotnet/runtime/actions/runs/1158715829

[karelz]

/backport to release/6.0-rc1

[github-actions]

Started backporting to release/6.0-rc1: https://github.com/dotnet/runtime/actions/runs/1161483669