Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

In a dot net core 8 application, health checks executed on a regular interval eventually leak all available memory, causing the container to crash.

Expected Behavior

Health check should not leak memory. Memory usage should remain relatively consistent or at least be reclaimed by garbage collection.

Steps To Reproduce

Reproduced with the following system configuration:

• Windows 11 build 22631.3155
• SDK: 8.0.102
• Runtime: 8.0.2

1. Setup new dot net core web API application using .NET 8 as the target framework
2. Modify the auto generated Program.cs to include the following block of code

        builder.Services.AddHealthChecks();

        var app = builder.Build();
        app.MapHealthChecks("/hc", new HealthCheckOptions
        {
            AllowCachingResponses = false,
        });

From there, run the program with a memory profiler (I used DotMemory version 2023.3.3). Notice that each time /hc is called, the health check leaks ~100KB of RAM.

Now, modify the *.csproj file to change the target framework to dot net 6;

<TargetFramework>net6.0</TargetFramework>

Note:

• You will need to remove the OpenAPI reference in the *.csproj
• You will also need to remove the .WithOpenApi(); extension in Program.cs

Now repeat the profiling exercise. Notice that, although the memory is not 100% constant, it doesn't really exhibit "leaking" behavior.

Please advise as to how to proceed. If you setup a docker container to poll the service at ~10 second intervals, you'll end up with hundreds of MBs of RAM leaked over a few hour timeframe.

Severity: SEVERE; risk of production crash. Framework is effectively not usable.

Exceptions (if any)

Memory should not leak during basic health check.

.NET Version

8.0.102

Anything else?

Similar to issue reported in the runtime itself, dotnet/runtime#99304