Getting Started

This page will show you how to get started with OpenTelemetry .NET Automatic Instrumentation.

If you are looking for a way to manually instrument your application, check out this guide.

You will learn how you can instrument a simple .NET application automatically, in such a way that traces, metrics and logs are emitted to the console.

Prerequisites

Ensure that you have the following installed locally:

• .NET SDK 6+

Example Application

The following example uses a basic Minimal API with ASP.NET Core application. If you are not using ASP.NET Core, that’s OK — you can still use OpenTelemetry .NET Automatic Instrumentation.

For more elaborate examples, see examples.

Create and launch an HTTP Server

To begin, set up an environment in a new directory called dotnet-simple. Within that directory, execute following command:

dotnet new web

In the same directory, replace the content of Program.cs with the following code:

using System.Globalization;

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

var logger = app.Logger;

int RollDice()
{
    return Random.Shared.Next(1, 7);
}

string HandleRollDice(string? player)
{
    var result = RollDice();

    if (string.IsNullOrEmpty(player))
    {
        logger.LogInformation("Anonymous player is rolling the dice: {result}", result);
    }
    else
    {
        logger.LogInformation("{player} is rolling the dice: {result}", player, result);
    }

    return result.ToString(CultureInfo.InvariantCulture);
}

app.MapGet("/rolldice/{player?}", HandleRollDice);

app.Run();

In the Properties subdirectory, replace the content of launchSettings.json with the following:

{
  "$schema": "http://json.schemastore.org/launchsettings.json",
  "profiles": {
    "http": {
      "commandName": "Project",
      "dotnetRunMessages": true,
      "launchBrowser": true,
      "applicationUrl": "http://localhost:8080",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

Build and run the application with the following command, then open http://localhost:8080/rolldice in your web browser to ensure it is working.

dotnet build
dotnet run

Instrumentation

Next, you’ll use a OpenTelemetry .NET Automatic Instrumentation to instrument the application at launch time. While you can configure .NET Automatic Instrumentation in a number of ways, the steps below use Unix-shell or PowerShell scripts.

Note: PowerShell commands require elevated (administrator) privileges.

1. Download installation scripts from Releases of the opentelemetry-dotnet-instrumentation repository:

   • Unix-shell
   • PowerShell

   curl -L -O https://github.com/open-telemetry/opentelemetry-dotnet-instrumentation/releases/latest/download/otel-dotnet-auto-install.sh
   

   $module_url = "https://github.com/open-telemetry/opentelemetry-dotnet-instrumentation/releases/latest/download/OpenTelemetry.DotNet.Auto.psm1"
   $download_path = Join-Path $env:temp "OpenTelemetry.DotNet.Auto.psm1"
   Invoke-WebRequest -Uri $module_url -OutFile $download_path -UseBasicParsing
   

2. Execute following script to download automatic instrumentation for your development environment:

   • Unix-shell
   • PowerShell

   ./otel-dotnet-auto-install.sh
   

   Import-Module $download_path
   Install-OpenTelemetryCore
   

3. Set and export variables that specify a console exporter, then execute script configuring other necessary environment variables using a notation suitable for your shell/terminal environment — we illustrate a notation for bash-like shells and PowerShell:

   • Unix-shell
   • PowerShell

   export OTEL_TRACES_EXPORTER=console \
     OTEL_METRICS_EXPORTER=console \
     OTEL_LOGS_EXPORTER=console
     OTEL_SERVICE_NAME=RollDiceService
   . $HOME/.otel-dotnet-auto/instrument.sh
   

   $env:OTEL_TRACES_EXPORTER="console"
   $env:OTEL_METRICS_EXPORTER="console"
   $env:OTEL_LOGS_EXPORTER="console"
   Register-OpenTelemetryForCurrentSession -OTelServiceName "RollDiceService"
   

4. Run your application once again:

   dotnet run
   

   Note the output from the dotnet run.

5. From another terminal, send a request using curl:

   curl localhost:8080/rolldice
   

6. After about 30 sec, stop the server process.

At this point, you should see trace and log output from the server and client that looks something like this (output is line-wrapped for readability):

LogRecord.Timestamp:               2023-08-14T06:44:53.9279186Z
LogRecord.TraceId:                 3961d22b5f90bf7662ad4933318743fe
LogRecord.SpanId:                  93d5fcea422ff0ac
LogRecord.TraceFlags:              Recorded
LogRecord.CategoryName:            simple-dotnet
LogRecord.LogLevel:                Information
LogRecord.StateValues (Key:Value):
    result: 1
    OriginalFormat (a.k.a Body): Anonymous player is rolling the dice: {result}

Resource associated with LogRecord:
service.name: simple-dotnet
telemetry.auto.version: 0.7.0
telemetry.sdk.name: opentelemetry
telemetry.sdk.language: dotnet
telemetry.sdk.version: 1.4.0.802

info: simple-dotnet[0]
      Anonymous player is rolling the dice: 1
Activity.TraceId:            3961d22b5f90bf7662ad4933318743fe
Activity.SpanId:             93d5fcea422ff0ac
Activity.TraceFlags:         Recorded
Activity.ActivitySourceName: OpenTelemetry.Instrumentation.AspNetCore
Activity.DisplayName:        /rolldice
Activity.Kind:               Server
Activity.StartTime:          2023-08-14T06:44:53.9278162Z
Activity.Duration:           00:00:00.0049754
Activity.Tags:
    net.host.name: localhost
    net.host.port: 8080
    http.method: GET
    http.scheme: http
    http.target: /rolldice
    http.url: http://localhost:8080/rolldice
    http.flavor: 1.1
    http.user_agent: curl/8.0.1
    http.status_code: 200
Resource associated with Activity:
    service.name: simple-dotnet
    telemetry.auto.version: 0.7.0
    telemetry.sdk.name: opentelemetry
    telemetry.sdk.language: dotnet
    telemetry.sdk.version: 1.4.0.802

Also when stopping the server, you should see an output of all the metrics collected (sample excerpt shown):

Export process.runtime.dotnet.gc.collections.count, Number of garbage collections that have occurred since process start., Meter: OpenTelemetry.Instrumentation.Runtime/1.1.0.2
(2023-08-14T06:12:05.8500776Z, 2023-08-14T06:12:23.7750288Z] generation: gen2 LongSum
Value: 2
(2023-08-14T06:12:05.8500776Z, 2023-08-14T06:12:23.7750288Z] generation: gen1 LongSum
Value: 2
(2023-08-14T06:12:05.8500776Z, 2023-08-14T06:12:23.7750288Z] generation: gen0 LongSum
Value: 6

...

Export http.client.duration, Measures the duration of outbound HTTP requests., Unit: ms, Meter: OpenTelemetry.Instrumentation.Http/1.0.0.0
(2023-08-14T06:12:06.2661140Z, 2023-08-14T06:12:23.7750388Z] http.flavor: 1.1 http.method: POST http.scheme: https http.status_code: 200 net.peer.name: dc.services.visualstudio.com Histogram
Value: Sum: 1330.4766000000002 Count: 5 Min: 50.0333 Max: 465.7936
(-Infinity,0]:0
(0,5]:0
(5,10]:0
(10,25]:0
(25,50]:0
(50,75]:2
(75,100]:0
(100,250]:0
(250,500]:3
(500,750]:0
(750,1000]:0
(1000,2500]:0
(2500,5000]:0
(5000,7500]:0
(7500,10000]:0
(10000,+Infinity]:0

What next?

For more:

• To configure exporters, samplers, resources and more, see Configuration and settings
• See the list of available instrumentations
• If you want to combine automatic and manual instrumentation, learn how you can create custom traces and metrics
• If you face any issues, check the Troubleshooting Guide