Removing Windows Specifc performance counter dependency with cross platfrom EventCounters

[madhub]

Currently Redis client implementation depends PerformanceCounter class to get CPU time, which brings additional Windows specific nuget package Microsoft.Win32.Registry,System.Configuration.ConfigurationManager each of these inturn brings additional packages creating dependency hell , instead of this it is better to use cross platform EventCounters .
As EventCounters is available in .NET 3.1 on wards , we can use it for .NET Core 3.1 target & older targets still use the PerformanceCounter as is.

Sample implementation of how to get cpu-usage is from Event Counter

Reference Resource

• Event Counter Docs
• EventCounters Design
• .NET Core Counters internals

[mgravell]

Sounds good to me

[NickCraver]

I may be missing it here, but I don't think this counter exists in the EventCounters space. There's a subtle but important difference: we're using _Total, which is total CPU by all processes (the goal being to see if the box is pegged and unable to handle the load). The EventCounters space is for this process. For example the process could be at 2% CPU while some beast beside it is eating the other 98% and the box would be pegged...but we wouldn't get a useful metric there.

If there's a way to get global in a fewer dependency way I am also all for it, just not aware of that path at the moment :)

[madhub]

@NickCraver I saw below code in RavenDB , to calculate CPU usage for Windows/Linux/Mac
Is this something can be used in this project ( if source license allows ) ?
https://github.com/ravendb/ravendb/blob/f773b7da6e8afccad88549ee528fd1165878baa1/src/Raven.Server/Utils/Cpu/CpuUsageCalculator.cs

[NickCraver]

@madhub it's possible, but that's baking in multiple system calls cross-platform into the library which I think makes things worse for cases like #1442 that we want to solve with net6.0-<platform> potentially. It'd be nice if someone had a library for this specific stat, maybe it does exist...or we should propose the API for .NET 7 as a longer-term solution.

[NickCraver]

Given this approach isn't viable in the library but the over platform TFMs are on the table, I'm going to tidy up this issue and we'll remain open to adding those TFMs if needed.

[NickCraver]

Heads up: we revisited this based on issue data and me crawling old issues again to see effectiveness. Not fixed in terms of how to fetch, just removed as not-worth-it tradeoff given even more downsides with vulnerabilities downstream. Version 2.6.80+ will no longer reference System.Diagnostics.PerformanceCounter.