Norr.PerformanceMonitor is a library that can be easily integrated into ASP.NET Core applications to collect performance metrics and export them to systems like Prometheus.

1. Installation

Install via NuGet:

dotnet add package Norr.PerformanceMonitor

This package includes the core performance measurement infrastructure, metric collectors (Monitor, PerformanceScope), and basic exporters.

2. Program.cs Integration (Minimal Example)

Add the following integration to your Program.cs file in your ASP.NET Core application:

using Microsoft.AspNetCore.Routing;
using Norr.PerformanceMonitor.Abstractions;
using Norr.PerformanceMonitor.DependencyInjection;
using Norr.PerformanceMonitor.Integrations.AspNetCore;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddPerformanceMonitor();
builder.Services.AddControllers();

var app = builder.Build();

app.UseRouting();
app.UseRouteTagging();
app.UseMiddleware<PerformanceMiddleware>();

app.Use(async (ctx, next) =>
{
    var monitor = ctx.RequestServices.GetRequiredService<IMonitor>();
    var route = (ctx.GetEndpoint() as RouteEndpoint)?.RoutePattern.RawText
                ?? ctx.Request.Path.Value ?? "/";
    using (monitor.Begin($"http {ctx.Request.Method} {route}"))
        await next();
});

app.MapControllers();
app.UseNorrPrometheusEndpoint("/metrics");

app.Run();

With this setup, your application will start exposing metrics in Prometheus format at the /metrics endpoint.

3. First Run and Metrics Check

Run the application:

dotnet run

Make a request to an endpoint:

curl https://xxxx:yyyy/orders/42/details

Then check the metrics:

curl https://xxxx:yyyy/metrics

Example output:

# TYPE http_GET_orders__id__details summary
http_GET_orders__id__details_count 5
http_GET_orders__id__details_sum 400

These values show the total number of calls and duration/memory measurements for the given endpoint.

4. Optional Configuration (appsettings.json)

Add PerformanceOptions to your appsettings.json:

{
  "PerformanceOptions": {
    "Metrics": {
      "Temporality": "Cumulative",
      "EnableDuplicateGuard": true
    },
    "Exporters": {
      "Console": true,
      "Prometheus": true
    },
    "Scrubbing": {
      "MaskSensitiveValues": true,
      "NormalizePaths": true,
      "Mask": "***",
      "DropBannedKeys": false,
      "BannedKeys": [ "user.email", "http.authorization" ]
    }
  }
}

And add this to your Program.cs:

builder.Services.Configure<PerformanceOptions>(
    builder.Configuration.GetSection("PerformanceOptions"));

With these settings:

• Console exporter is enabled → prints a summary log at startup.
• Prometheus exporter remains enabled.
• Scrubbing masks sensitive data and normalizes path parameters.

5. Conclusion

With these steps, Norr.PerformanceMonitor is integrated into your project. The first metrics appear at the /metrics endpoint. Optional settings allow you to easily manage exporter and scrubbing behavior.