Caching demo using metrics

consoleapp.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

	<ItemGroup>
		<PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="7.0.0-preview.5.22253.2" />
		<PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="7.0.0-preview.5.22253.2" />
	</ItemGroup>

</Project>

Program.cs

using Microsoft.Extensions.Caching.Memory;
using System.Diagnostics.Metrics;

class Program
{
    static Meter s_meter = new Meter("Microsoft.Extensions.Caching.Memory.MemoryCache", "1.0.0");
    static IMemoryCache? mc1;
    static IMemoryCache? mc2;

    static void Main(string[] args)
    {
        s_meter.CreateObservableGauge<long>("cache-hits", GetCacheHits);
        s_meter.CreateObservableGauge<long>("cache-miss", GetCacheMiss);
        s_meter.CreateObservableGauge<long>("cache-count", GetCurrentEntryCount);
        s_meter.CreateObservableGauge<long>("cache-size", GetCurrentEstimatedSize);

        mc1 = new MemoryCache(new MemoryCacheOptions() { TrackStatistics = true, SizeLimit = 30 });
        mc2 = new MemoryCache(new MemoryCacheOptions() { TrackStatistics = true, SizeLimit = 30 });

        var obj = new object();
        string key1 = "myKey1";
        string key2 = "myKey2";

        using (var entry = mc1.CreateEntry(key1))
        {
            entry.SetValue(obj);
            entry.SetSize(10);
            mc1.Set(key1, obj, new MemoryCacheEntryOptions() { Size = 10 });
        }

        using (var entry = mc2.CreateEntry(key2))
        {
            entry.SetValue(obj);
            entry.SetSize(10);
            mc2.Set(key2, obj, new MemoryCacheEntryOptions() { Size = 10 });
        }


        while (mc1.TryGetValue(key1, out object? value))
        {
            mc2.TryGetValue("missingKey", out object? value2);
            mc2.TryGetValue("missingKey", out value2);
            mc2.TryGetValue("missingKey", out value2);
            mc2.TryGetValue(key2, out value2);
            Thread.Sleep(1000);
        }

        Console.WriteLine("Press any key to exit");
        Console.ReadLine();
    }

    static IEnumerable<Measurement<long>> GetCacheHits()
    {
        return new Measurement<long>[]
        {
            new Measurement<long>(mc1!.GetCurrentStatistics()!.TotalHits, new KeyValuePair<string,object?>("CacheName", "mc1")),
            new Measurement<long>(mc2!.GetCurrentStatistics()!.TotalHits, new KeyValuePair<string,object?>("CacheName", "mc2")),
        };
    }

    static IEnumerable<Measurement<long>> GetCacheMiss()
    {
        return new Measurement<long>[]
        {
            new Measurement<long>(mc1!.GetCurrentStatistics()!.TotalMisses, new KeyValuePair<string,object?>("CacheName", "mc1")),
            new Measurement<long>(mc2!.GetCurrentStatistics()!.TotalMisses, new KeyValuePair<string,object?>("CacheName", "mc2")),
        };
    }

    static IEnumerable<Measurement<long>> GetCurrentEntryCount()
    {
        return new Measurement<long>[]
        {
            new Measurement<long>(mc1!.GetCurrentStatistics()!.CurrentEntryCount, new KeyValuePair<string,object?>("CacheName", "mc1")),
            new Measurement<long>(mc2!.GetCurrentStatistics()!.CurrentEntryCount, new KeyValuePair<string,object?>("CacheName", "mc2")),
        };
    }

    static IEnumerable<Measurement<long>> GetCurrentEstimatedSize()
    {
        return new Measurement<long>[]
        {
            new Measurement<long>(mc1!.GetCurrentStatistics()!.CurrentEstimatedSize!.Value, new KeyValuePair<string,object?>("CacheName", "mc1")),
            new Measurement<long>(mc2!.GetCurrentStatistics()!.CurrentEstimatedSize!.Value, new KeyValuePair<string,object?>("CacheName", "mc2")),
        };
    }
}

>  dotnet-counters monitor -n ConsoleApp78 --counters System.Runtime[cpu-usage,working-set],Microsoft.Extensions.Caching.Memory.MemoryCache

Gives:

Press p to pause, r to resume, q to quit.
    Status: Running

[System.Runtime]
    CPU Usage (%)                                      0
    Working Set (MB)                                  14
[Microsoft.Extensions.Caching.Memory.MemoryCache]
    cache-count
        CacheName=mc1                                  1
        CacheName=mc2                                  1
    cache-hits
        CacheName=mc1                             13,204
        CacheName=mc2                             13,204
    cache-miss
        CacheName=mc1                                  0
        CacheName=mc2                             39,612
    cache-size
        CacheName=mc1                                 10
        CacheName=mc2                                 10