ApplicationInsights dotnet core custom initializer - asp.net-core

Question

I'm unable to figure out how to configure AI for aspnetcore project. I've done the following:
services.AddSingleton<ITelemetryInitializer, AppInsightsInitializer>();
services.AddApplicationInsightsTelemetry(Configuration);
Where I need the loggedin user and the servicename so I've got this initializer:
public class AppInsightsInitializer : ITelemetryInitializer
{
private IHttpContextAccessor _httpContextAccessor;
public AppInsightsInitializer(IHttpContextAccessor httpContextAccessor)
{
_httpContextAccessor = httpContextAccessor ?? throw new ArgumentNullException("httpContextAccessor");
}
public void Initialize(ITelemetry telemetry)
{
var httpContext = _httpContextAccessor.HttpContext;
telemetry.Context.Properties["appname"] = "MyCoolService";
if (httpContext != null && httpContext.User.Identity.IsAuthenticated == true && httpContext.User.Identity.Name != null)
{
telemetry.Context.User.AuthenticatedUserId = httpContext.User.Identity.Name;
}
}
}
I've got no applicationinights.config file (I understand they are not needed)
Problem: I got 4 entries of each log (same id). The data is correct. I also got the following errror in the logs:
AI: Error collecting 9 of the configured performance counters. Please check the configuration. Counter \Process(??APP_WIN32_PROC??)\% Processor Time: Failed to perform the first read for performance counter. Please make sure it exists.
Category: Process, counter: % Processor Time, instance Counter \Memory\Available Bytes: Failed to register performance counter.
Category: Memory, counter: Available Bytes, instance: .
Counter \ASP.NET Applications(??APP_W3SVC_PROC??)\Requests/Sec: Failed to perform the first read for performance counter. Please make sure it exists.
Category: ASP.NET Applications, counter: Requests/Sec, instance MyCoolv3.Api.exe Counter \.NET CLR Exceptions(??APP_CLR_PROC??)\# of Exceps Thrown / sec: Failed to perform the first read for performance counter. Please make sure it exists.
Category: .NET CLR Exceptions, counter: # of Exceps Thrown / sec, instance Counter \ASP.NET Applications(??APP_W3SVC_PROC??)\Request Execution Time: Failed to perform the first read for performance counter. Please make sure it exists.
Category: ASP.NET Applications, counter: Request Execution Time, instance MyCoolv3.Api.exe Counter \Process(??APP_WIN32_PROC??)\Private Bytes: Failed to perform the first read for performance counter. Please make sure it exists. Category: Process, counter: Private Bytes, instance Counter \Process(??APP_WIN32_PROC??)\IO Data Bytes/sec: Failed to perform the first read for performance counter. Please make sure it exists.
Category: Process, counter: IO Data Bytes/sec, instance Counter \ASP.NET Applications(??APP_W3SVC_PROC??)\Requests In Application Queue: Failed to perform the first read for performance counter. Please make sure it exists. Category: ASP.NET Applications, counter: Requests In Application Queue, instance MyCoolv3.Api.exe
Counter \Processor(_Total)\% Processor Time: Failed to register performance counter. Category: Processor, counter: % Processor Time, instance: _Total.
I'm using:
<PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.1.0-beta1" />
<PackageReference Include="Microsoft.AspNetCore" Version="1.1.1" />
<PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />

Answer 1

services.AddApplicationInsightsTelemetry(Configuration);
isn't needed anymore (hypothetically, you should even be getting deprecation warnings on that line?)
if you create a asp.net core new project in VS2017, AI will already be there in package references (though the 2.0 version, not that 2.1 beta version), and all of the wireup would already be done in program.cs and in some other files.
If you're porting an existing one, then instead of the above AddApplicationInsights... line, instead you'd have
.UseApplicationInsights()
in your program.cs startup of your app instead. for more details, there's some info about this in the 2.1 beta release notes on github
We're also working on updating the "configure application insights" tools in VS2017 to properly "migrate" apps like this in a future update.
I'm not sure why you'd get multiple instances of any events unless you're explicitly logging them, or if you possibly have multiple calls to startup (which also shouldn't affect anything). Where are are you seeing multiple instances? in VS's appinsights tools? in the portal?