Skip to content

README.md

Latest commit

 

History

History
96 lines (79 loc) · 3.42 KB

README.md

File metadata and controls

96 lines (79 loc) · 3.42 KB

Getting Started with OpenTelemetry .NET Metrics in 5 Minutes - ASP.NET Core Application

First, download and install the .NET SDK on your computer.

Create a new web application:

dotnet new web -o aspnetcoreapp
cd aspnetcoreapp

Install the OpenTelemetry.Exporter.Console, OpenTelemetry.Extensions.Hosting, and OpenTelemetry.Instrumentation.AspNetCore packages:

dotnet add package OpenTelemetry.Exporter.Console
dotnet add package OpenTelemetry.Extensions.Hosting
dotnet add package OpenTelemetry.Instrumentation.AspNetCore

Update the Program.cs file with the code from Program.cs.

Run the application again (using dotnet run) and then browse to the url shown in the console for your application (ex http://localhost:5154). You should see the metrics output from the console.

Metric Name: http.server.request.duration, Description: Duration of HTTP server requests., Unit: s, Metric Type: Histogram
Instrumentation scope (Meter):
        Name: Microsoft.AspNetCore.Hosting
(2026-04-02T22:41:03.8661885Z, 2026-04-02T22:41:12.0061720Z] http.request.method: GET http.response.status_code: 200 http.route: / network.protocol.version: 1.1 url.scheme: http
Value: Sum: 0.0276842 Count: 1 Min: 0.0276842 Max: 0.0276842
(-Infinity,0.005]:0
(0.005,0.01]:0
(0.01,0.025]:0
(0.025,0.05]:1
(0.05,0.075]:0
(0.075,0.1]:0
(0.1,0.25]:0
(0.25,0.5]:0
(0.5,0.75]:0
(0.75,1]:0
(1,2.5]:0
(2.5,5]:0
(5,7.5]:0
(7.5,10]:0
(10,+Infinity]:0

Congratulations! You are now collecting metrics using OpenTelemetry.

What does the above program do?

The program uses the OpenTelemetry.Instrumentation.AspNetCore package to automatically create metrics for incoming ASP.NET Core requests, uses the OpenTelemetry.Exporter.Console package to write metrics to the console every 1000 milliseconds. This is done by configuring an OpenTelemetry MeterProvider using extension methods and setting it to auto-start when the host is started:

builder.Services.AddOpenTelemetry()
    .ConfigureResource(resource => resource
        .AddService(serviceName: builder.Environment.ApplicationName))
    .WithMetrics(metrics => metrics
        .AddAspNetCoreInstrumentation()
        .AddConsoleExporter((exporterOptions, metricReaderOptions) =>
        {
            metricReaderOptions.PeriodicExportingMetricReaderOptions.ExportIntervalMilliseconds = 1000;
        }));

Note

The AddOpenTelemetry extension is part of the OpenTelemetry.Extensions.Hosting package.

The index route ("/") is set up to write out a greeting message on the response:

app.MapGet("/", () => $"Hello from OpenTelemetry Metrics!");

Learn more