ITelemetryProcessor for Application Insights to filter out Umbraco's ping requests, learn more at https://swimburger.net/blog/umbraco/ignoring-umbraco-ping-from-azure-application-insights

PingFilter.cs

using Microsoft.ApplicationInsights.Channel;
using Microsoft.ApplicationInsights.DataContracts;
using Microsoft.ApplicationInsights.Extensibility;
using System;

namespace YourApp.ApplicationInsights
{
    public class PingFilter : ITelemetryProcessor
    {
        //next processor in the pipeline
        private readonly ITelemetryProcessor next;

        public PingFilter(ITelemetryProcessor next)
        {
            //store next processor in the pipeline
            this.next = next;
        }

        //our logic goes here
        public void Process(ITelemetry telemetry)
        {
            //check to see if telemetry is for a Request
            var request = telemetry as RequestTelemetry;
            //ignore if RequestTelemetry is a ping request
            if (request?.Url?.AbsolutePath.Equals("/umbraco/ping.aspx", StringComparison.OrdinalIgnoreCase) == true)
            {
                //stop pipeline
                return;
            }

            //invoke next processor
            next.Process(telemetry);
        }
    }
}