Application Insights MediatR Operation Behavior

ApplicationInsightsBehavior.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using MediatR;
using Microsoft.ApplicationInsights;
using Microsoft.ApplicationInsights.DataContracts;
using Microsoft.ApplicationInsights.Extensibility;

namespace BenjaminAbt.ApplicationInsights.MediatR
{
    // requiresservices.AddApplicationInsightsTelemetry();
    public class ApplicationInsightsBehavior<TRequest, TResponse> : IPipelineBehavior<TRequest, TResponse> where TRequest : notnull
    {
        private readonly TelemetryClient _telemetryClient;

        public ApplicationInsightsBehavior(TelemetryClient telemetryClient)
        {
            _telemetryClient = telemetryClient;
        }

        public async Task<TResponse> Handle(
            TRequest request,
            CancellationToken cancellationToken,
            RequestHandlerDelegate<TResponse> next)
        {
            // use type name as command name
            string commandName = typeof(TRequest).Name;

            using IOperationHolder<DependencyTelemetry> operation = _telemetryClient.StartOperation<DependencyTelemetry>(commandName);

            TResponse response;
            try
            {
                response = await next().ConfigureAwait(false);

                operation.Telemetry.Success = true;
            }
            catch (Exception e)
            {
                operation.Telemetry.Success = false;
                _telemetryClient.TrackException(e);

                throw;
            }

            return response;
        }
    }
}

Requires

services.AddApplicationInsightsTelemetry();

in your DI registration.

Register the Behavior via

services.AddMediatR();
services.AddTransient(typeof(IPipelineBehavior<,>), typeof(ApplicationInsightsBehavior<,>));