Azure WebJobs - How to disable adaptive sampling for application insights?

Question

I came across this MSDN article on configuring AppInsights sampling for various types of apps.

However I could not find a way to configure it for azure webjobs.

When it comes to configuring appinsights for the WebJob it would look something like this (MSDN):

static async Task Main()
{
    var builder = new HostBuilder();
    builder.UseEnvironment(EnvironmentName.Development);
    builder.ConfigureWebJobs(b =>
            {
                b.AddAzureStorageCoreServices();
                b.AddAzureStorage();
            });
    builder.ConfigureLogging((context, b) =>
            {
                b.AddConsole();

                // If the key exists in settings, use it to enable Application Insights.
                string instrumentationKey = context.Configuration["APPINSIGHTS_INSTRUMENTATIONKEY"];
                if (!string.IsNullOrEmpty(instrumentationKey))
                {
                    b.AddApplicationInsightsWebJobs(o => o.InstrumentationKey = instrumentationKey);
                }
            });
    var host = builder.Build();
    using (host)
    {
        await host.RunAsync();
    }
}

The relevant code is:

b.AddApplicationInsightsWebJobs(o => o.InstrumentationKey = instrumentationKey);

The options itself is as follows:

Is it possible to disable adaptive sampling?

Any help is much appreciated. Thank you!

Answer 1

Simplest way is to set the SamplingSettings property to null:

.ConfigureLogging((loggingContext, builder) =>
{
    builder.AddConsole();
    builder.AddApplicationInsightsWebJobs(o =>
    {
        o.SamplingSettings = null;
    });
})

This prevents the AdaptiveSamplingTelemetryProcessor being added to the list of telemetry processors.

You can inspect whether adaptive sampling is active or not by taking a look at the TelemetryClient.TelemetryConfiguration.TelemetryProcessors property to see whether it contains an entry of type AdaptiveSamplingTelemetryProcessor or not.