Azure application insights disable favicon check

Question

I have a regular mvc app. How can I disable app insights from checking for favicon.ico?

Answer 1

You can write a custom TelemetryFilter that prevents telemetry from being send to application insights:

public class CustomTelemetryFilter : ITelemetryProcessor
{
    private readonly ITelemetryProcessor _next;

    public CustomTelemetryFilter(ITelemetryProcessor next)
    {
        _next = next;
    }

    public void Process(ITelemetry item)
    {
        // Example: process all telemetry except requests to favicon
        var isFavIconUrl = item is RequestTelemetry request && request.Url.ToString().EndsWith("favicon.ico");

        if (!isFavIconUrl)
            _next.Process(item); // Process the item only if it is not the request for favicon
    }
}

The last step is to register your filter, see the docs on how to do that for your specific runtime.