Kestrel Metrics

Kestrel Connections Dashboard

This Grafana dashboard provides detailed monitoring and visualization of ASP.NET Core Kestrel web server performance metrics. It focuses on connection-level metrics that are crucial for understanding your web application’s performance and behavior at the server level.

Source Code

View source for this dashboard here: https://github.com/petabridge/dotnet-grafana-dashboards/blob/master/kestrel/README.md

Dashboard Overview

The dashboard includes metrics for:

• Connection duration percentiles (p50, p75, p90, p98, p99)
• Active and queued connections
• Connections per instance of each application

Prerequisites

To use this dashboard, you need to have the OpenTelemetry.Instrumentation.AspNetCore package installed in your .NET application:

xml Copy

<ItemGroup>
    <PackageReference Include="OpenTelemetry.Instrumentation.AspNetCore" Version="{version}" />
</ItemGroup>

This dashboard is designed to work with Prometheus and the OTLP Exporter.

csharp Copy

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetry()
    .WithMetrics(metrics =>
    {
        metrics
            // OTHER METRICS SOURCES
            .AddAspNetCoreInstrumentation();
            
    })
    // traces, et al
    .UseOtlpExporter();

var app = builder.Build();

Installation

1. Import the dashboard into Grafana from Grafana Cloud:

2. Import the dashboard into Grafana as a JSON file:

   • Open Grafana
   • Navigate to Dashboards > Import
   • Click “Upload JSON file”
   • Select the kestrel-connections-dashboard.json file
   • Select your Prometheus data source
   • Click “Import”

Metrics Explanation

• Connection Duration: Shows how long Kestrel connections stay open, broken down by percentiles
• Active Connections: Real-time count of current open connections
• Connection Rate: Number of new connections per second
• Queue Length: Number of connections waiting to be processed