.NET (server-side) SDK observability reference

This topic documents how to get started with the LaunchDarkly observability plugin for the .NET (server-side) SDK.

Overview

This topic documents how to get started with the LaunchDarkly observability plugin for the .NET (server-side) SDK.

The .NET (server-side) SDK supports the observability plugin for error monitoring, logging, and tracing.

LaunchDarkly’s SDKs are open source. In addition to this reference guide, we provide source, API reference documentation, and a sample application:

Resource	Location
SDK API documentation	Observability plugin API docs
GitHub repository	@launchdarkly/observability-dotnet
Published module	NuGet

Prerequisites and dependencies

This reference guide assumes that you are somewhat familiar with the LaunchDarkly .NET (server-side) SDK.

The observability plugin is compatible with the .NET (server-side) SDK, version 8.10 and later.

This plugin is designed for use with ASP.Net Core or ASP.Net:

• When using .NET or netstandard2.0, the plugin works with ASP.Net Core
• When using .NET Framework, the plugin works with ASP.Net

Get started

Follow these steps to get started:

• Install the plugin
• Initialize the .NET (server-side) SDK client
• Configure the plugin options
• Explore supported features
• Review observability data in LaunchDarkly

Install the plugin

LaunchDarkly uses a plugin to the .NET (server-side) SDK to provide observability.

The first step is to make both the SDK and the observability plugin available as dependencies.

Here’s how:

Installation

    dotnet add package LaunchDarkly.ServerSdk
    dotnet add package LaunchDarkly.Observability

Then, import the LaunchDarkly SDK’s namespaces in your application code. The namespace is not the same as the package name:

.NET SDK v8.10+

    using LaunchDarkly.Sdk;
    using LaunchDarkly.Sdk.Server;
    using LaunchDarkly.Observability;

Initialize the client

Next, initialize the SDK and the plugin.

To initialize, you need your LaunchDarkly environment’s SDK key. This authorizes your application to connect to a particular environment within LaunchDarkly. To learn more, read Initialize the client in the .NET (server-side) SDK reference guide.

Here’s how to initialize the SDK and plugin:

Initialize, .NET SDK v8.10+ with ASP.Net Core

    var builder = WebApplication.CreateBuilder(args);

    var config = Configuration.Builder("YOUR_SDK_KEY")
      .StartWaitTime(TimeSpan.FromSeconds(5))
      .Plugins(new PluginConfigurationBuilder()
          .Add(ObservabilityPlugin.Builder(builder.Services)
              .WithServiceName("your-service-name")
              .WithServiceVersion("example-sha")
              .Build()
          )
      ).Build();

    var client = new LdClient(config);

    // Client must be constructed before the web application.
    var app = builder.Build();

Configure the plugin options

You can configure options for the observability plugin when you initialize the SDK. The plugin constructor takes an optional object with the configuration details.

Here is an example:

Plugin options, .NET SDK v8.10+

    var plugin = ObservabilityPlugin.Builder()
      .WithServiceName("example-service")
      .WithServiceVersion("example-sha")
      .Build("YOUR_SDK_KEY");

For more information on plugin options, as well as how they interact with environment variables and existing OpenTelemetry configuration, read Configuration for server-side observability.

Explore supported features

The observability plugin supports the following features. After the SDK and plugins are initialized, you can access these from within your application:

• Configuration for server-side observability
• Errors
• Logs
• Metrics
• Tracing

Review observability data in LaunchDarkly

After you initialize the SDK and observability plugin, your application automatically starts sending observability data back to LaunchDarkly in the form of custom events. You can review this information in the LaunchDarkly user interface. To learn how, read Observability and Metrics autogenerated from OpenTelemetry data.