Azure Monitor: Application Insights Sampling Strategies

At scale, telemetry volume overwhelms budgets. Sampling reduces data while preserving insights.

Adaptive Sampling (Default)

Automatically adjusts rate to stay within 5 items/second per server. Good for most cases.

Fixed-Rate Sampling

services.Configure<TelemetryConfiguration>(config =>
{
    var processor = new SamplingTelemetryProcessor(new NullTelemetryProcessor())
    {
        SamplingPercentage = 25 // Keep 25%
    };
    config.TelemetryProcessorChain.Use(processor);
});

Tip: Exclude failures and slow requests from sampling to ensure you never miss issues.