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Application Insights–OpenTelemetry integration for ASP.NET Core

OpenTelemetry is becoming THE standard of telemetry instrumentation. And thanks to the Azure Monitor OpenTelemetry Exporter we can keep using Application Insights as our tool of choice. In this post I'll walk you through the steps to link your OpenTelemetry enabled ASP.NET core application to Azure Monitor Application Insights.

Important to mention is that this feature is still in preview!

At the moment of writing distributed tracing and metrics are supported but some of the other features that we like from the Application Insights SDK are not available(yet).

What is not supported?

I copied the list from the documentation:

Add Azure Monitor OpenTelemetry Exporter to your ASP.NET Core application

Now that we now what isn’t available yet, let’s focus on what we can do and see how we can start instrumenting our ASP.NET Core application using OpenTelemetry.

Let’s start by adding the necessary Nuget packages:

dotnet add package --prerelease Azure.Monitor.OpenTelemetry.Exporter

We also add some extra packages to include extra instrumentation specific for ASP.NET Core:

dotnet add package --prerelease OpenTelemetry.Extensions.Hosting
dotnet add package --prerelease OpenTelemetry.Instrumentation.AspNetCore
dotnet add package --prerelease OpenTelemetry.Instrumentation.Http
dotnet add package --prerelease OpenTelemetry.Instrumentation.SqlClient

Now that we have all the packages we need, we can add the necessary instrumentation code:

We specified a servicename and version and added some extra attributes. But let’s take advantage of the extra instrumentation libraries we added and extend the configuration a little bit:

Last thing we need to add is the Azure Monitor OpenTelemetry exporter itself. Here we need to specify our Applications Insights connection string:

If we now run our application, our instrumentation data should be send to Application Insights.

More information: Enable Azure Monitor OpenTelemetry for .NET, Node.js, and Python applications - Azure Monitor | Microsoft Learn

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