.NET OpenTelemetry for Distributed Tracing: Complete Guide

By Sandeep Mhaske | January 2025

Table of Contents

• Introduction
• What is OpenTelemetry?
• Why Use OpenTelemetry in .NET?
• Key Features of OpenTelemetry
• Understanding Distributed Tracing
• Step-by-Step Implementation of OpenTelemetry
• Best Practices for OpenTelemetry
• Common Errors and Troubleshooting
• Conclusion

Introduction

As modern software systems become increasingly distributed, monitoring and tracing their performance has become more challenging. OpenTelemetry, an open-source observability framework, has emerged as a solution to these challenges. It provides tools for collecting and analyzing telemetry data, such as traces, metrics, and logs, to help developers monitor distributed systems effectively.

This blog dives into how to use .NET OpenTelemetry for distributed tracing. We will explore its features, advantages, implementation, and best practices, ensuring you gain a comprehensive understanding of integrating OpenTelemetry into your .NET applications.

What is OpenTelemetry?

OpenTelemetry is an open-source observability framework that provides APIs, SDKs, and instrumentation libraries for distributed tracing, metrics collection, and logging. It enables developers to monitor the performance and behavior of applications, making it easier to identify and resolve issues.

OpenTelemetry is vendor-agnostic and integrates seamlessly with observability platforms like Jaeger, Zipkin, and Prometheus. It has become a standard for tracing in modern distributed systems.

Why Use OpenTelemetry in .NET?

OpenTelemetry is an essential tool for .NET developers due to its ability to provide detailed insights into application performance. Here are some reasons to use OpenTelemetry in .NET:

• Monitor performance and identify bottlenecks in real-time.
• Gain visibility into complex distributed systems.
• Integrate with popular telemetry backends like Jaeger and Azure Monitor.
• Ensure application reliability by diagnosing issues quickly.
• Comply with industry standards for observability and monitoring.

Key Features of OpenTelemetry

• Support for distributed tracing, metrics, and logs.
• Cross-platform compatibility and vendor neutrality.
• Automatic instrumentation for .NET Core and ASP.NET Core applications.
• Built-in integration with observability platforms like Prometheus, Zipkin, and Jaeger.
• Extensibility through custom instrumentation and exporters.

Understanding Distributed Tracing

Distributed tracing tracks requests as they flow through multiple services in a distributed system. Each trace represents a unique transaction, while spans within a trace represent individual operations or service calls.

OpenTelemetry collects and aggregates trace data, providing a detailed view of how services interact. This helps developers understand performance bottlenecks and optimize system reliability.

Step-by-Step Implementation of OpenTelemetry

Step 1: Add OpenTelemetry NuGet Packages

Install the required NuGet packages in your .NET project:

dotnet add package OpenTelemetry
dotnet add package OpenTelemetry.Extensions.Hosting
dotnet add package OpenTelemetry.Exporter.Jaeger
            

Step 2: Configure OpenTelemetry

In your `Program.cs` file, configure OpenTelemetry with tracing and exporters:

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOpenTelemetryTracing(traceBuilder =>
{
    traceBuilder
        .AddAspNetCoreInstrumentation()
        .AddHttpClientInstrumentation()
        .AddJaegerExporter(options =>
        {
            options.AgentHost = "localhost";
            options.AgentPort = 6831;
        });
});

var app = builder.Build();

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

app.Run();
            

Step 3: Run and Monitor Traces

Start your application and configure your observability backend (e.g., Jaeger) to visualize traces. Ensure your OpenTelemetry exporter points to the correct backend address.

Best Practices for OpenTelemetry

• Use meaningful span names and attributes for better trace readability.
• Instrument all critical services and endpoints.
• Configure sampling rates to balance performance and observability.
• Secure telemetry data with encryption and authentication.
• Regularly monitor and fine-tune your OpenTelemetry configuration.

Common Errors and Troubleshooting

Some common issues with OpenTelemetry include:

• Missing traces due to misconfigured exporters or instrumentation.
• High latency caused by sampling or backend bottlenecks.
• Incorrect agent host and port settings for exporters.

Always validate configurations and monitor logs for errors during setup.

Conclusion

OpenTelemetry is a powerful framework for distributed tracing in .NET applications. By implementing OpenTelemetry, developers can gain deeper insights into their application's performance, identify bottlenecks, and ensure system reliability. With this guide, you are well-equipped to start using OpenTelemetry in your .NET projects.