Cannot turn off sampling of application insights

Question

I have a DotNet 6 application ASP.NET Web API application that is running as an App Service in Azure.

I do not have fixed sampling enabled. I also do not have applicationinsights.json file in my application.

I have code to disable Adaptive Sampling in the ConfigureServices method. The code snippet is below:

  if (!string.IsNullOrEmpty(configuration["ApplicationInsights:InstrumentationKey"]))
            {
                services.AddApplicationInsightsTelemetry(options =>
                {
                    if (webHostEnvironment.IsDevelopment())
                    {
                        options.DeveloperMode = true;
                        options.EnableDebugLogger = false;
                    }
                    options.EnableAdaptiveSampling = false;
                    options.InstrumentationKey = configuration["ApplicationInsights:InstrumentationKey"];
                });
                services.AddApplicationInsightsTelemetryProcessor<FilterProcessor>();
                services.AddSingleton<ITelemetryInitializer, NopContextInitializer>();
            }

My Azure settings for application insights is as follows for ingestion sampling

I continue to see sampling happening when I run the below query:

union requests,dependencies,pageViews,browserTimings,exceptions,traces
| where timestamp > ago(1d)
| summarize RetainedPercentage = 100/avg(itemCount) by bin(timestamp, 1h), itemType

My application was a .NET Core 3.1 a few weeks back and could not get sampling to be turned off. Even after upgrading to DotNet 6, I am not able to turn off sampling.

Any pointers on why this may be happening ?

Answer 1

I also do not have applicationinsights.json file in my application.

When we add Application Insights Telemetry from Visual Studio => Project Root Folder, by default ApplicationInsights.config used to be generated automatically.

I have Added Application Insights Telemetry from Project Root Folder, even I didn't find ApplicationInsights.config added in the application.

There might be some latest changes in Adding the ApplicationInsights Telemetry.

We can disable sampling from either ApplicationInsights.config or from code.

As we don't have ApplicationInsights.config file, will try to disable the sampling from Code.

As mentioned in the MSDoc,

Only ASP.NET server-side telemetry currently supports adaptive sampling.

In Program.cs, add the below lines of code

var aiOptions = new Microsoft.ApplicationInsights.AspNetCore.Extensions.ApplicationInsightsServiceOptions();
aiOptions.EnableAdaptiveSampling = false; 
builder.Services.AddApplicationInsightsTelemetry(aiOptions);

• This code works only for the Production Environment(Deployed Application).

For .NET Core 6

My Program.cs

using Microsoft.ApplicationInsights.Channel;
using Microsoft.ApplicationInsights.WindowsServer.TelemetryChannel;
using Microsoft.ApplicationInsights.Extensibility;
var builder = WebApplication.CreateBuilder(args);

var aiOptions = new Microsoft.ApplicationInsights.AspNetCore.Extensions.ApplicationInsightsServiceOptions();
aiOptions.EnableAdaptiveSampling = false;
builder.Services.AddApplicationInsightsTelemetry(aiOptions);

builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

if (app.Environment.IsDevelopment())
{
   app.UseSwagger();
   app.UseSwaggerUI();
}

app.UseHttpsRedirection();
app.UseAuthorization();
app.MapControllers();
app.Run();

My appsettings.json file

{
  "Logging": {
    "ApplicationInsights": {
      "LogLevel": {
        "Default": "Debug",
        "Microsoft": "Error"
      }
    },
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*",
  "ApplicationInsights": {
    "ConnectionString": "InstrumentationKey=********;IngestionEndpoint=https://****.in.applicationinsights.azure.com/;LiveEndpoint=https://****.livediagnostics.monitor.azure.com/",
    "EnableAdaptiveSampling": false,
    "EnablePerformanceCounterCollectionModule": false
  }
}

• Re-deploy the App, Access the URL and check the traces/Logs.

References taken from MSDoc