Update dotnet-counters help text for .NET 5

[davidsh]

ASP.NET Core has added new counters for .NET 5. PR: dotnet/aspnetcore#21649

.NET runtime stack (System.Net.* components) will be adding new counters shortly as well.

The help text in KnownData.cs needs to be updated with these new counters.

[davidsh]

@davidfowl

[BrennanConroy]

Are there rules for what counters we add to this list? Because there are a lot more that aren't mentioned.

[davidsh]

Are there rules for what counters we add to this list? Because there are a lot more that aren't mentioned.

Things that ship in the "shared framework" are considered part of "known counters". That would include .NET runtime (Microsoft.NETCore.App package) and ASP.NET Core.

@noahfalk Can you clarify this?

[noahfalk]

We didn't have any formalized rules on this, I think the ad-hoc criteria is:
a) part of the .NET platform
b) stable (no plan to change or remove the counter in the future)
c) we expect some customers would find them useful

In the future I hope to have something that automatically enumerates counters in a process, but for now we've been doing it on the cheap. Thanks for the heads up about the new counters!

[cijothomas]

@sywhang Is there a good place where I can find the entire list of counters which meet the criteria Noah listed above? I am trying to document ApplicationInsights EventCounter doc, to add a link to the list of "known counters".
(We recently removed all default EventCounters from ApplicationInsights. Now its upto customers to enable individual counters. So trying to point them to a good list)

[sywhang]

There isn't a place with docs on these counters other than just the dotnet-counters tool itself. So for now, I think the best place to find them is using the dotnet-counters list command. This is something I hope to document to the docs.microsoft.com page some time this week or next week.