Recording Application Metrics

App Metrics provides access to an IMetrics instance, registered as a single instance. This can be injected where required to start recording different types of metrics.

Each metric being measured should be described through one of the below classes, which provides details about the metric being measured.

Options Description
GaugeOptions Allows the metric context, metric name, unit of measurement, and tags to be specified.
CounterOptions Allows the metric context, metric name, unit of measurement, and tags to be specified.
MeterOptions Allows the metric context, metric name, unit of measurement, rate unit and tags to be specified.
TimerOptions Allows the metric context, metric name, unit of measurement, rate unit, duration unit, sampling type and tags to be specified. Also allows a custom IReservoir to be used for sampling.
HistogramOptions Allows the metric context, metric name, unit of measurement, sampling type and tags to be specified. Also allows a custom IReservoir to be used for sampling.

Name is the only required property is the property on each metric option instance.

Declaring Metrics

public static class AppMetricsRegistery
{
    public static GaugeOptions Errors { get; } = new GaugeOptions
    {
        Name = "Errors"            
    };

    public static CounterOptions SampleCounter { get; } = new CounterOptions
    {
        Name = "Sample Counter",
        MeasurementUnit = Unit.Calls,
    };

    public static HistogramOptions SampleHistogram { get; } = new HistogramOptions
    {
        Name = "Sample Histogram",
        Reservoir = new Lazy<IReservoir>(() => new DefaultAlgorithmRReservoir()),
        MeasurementUnit = Unit.MegaBytes            
    };

    public static MeterOptions SampleMeter { get; } = new MeterOptions
    {
        Name = "Sample Meter",
        MeasurementUnit = Unit.Calls            
    };

    public static TimerOptions SampleTimer { get; } = new TimerOptions
    {
        Name = "Sample Timer",
        MeasurementUnit = Unit.Items,
        DurationUnit = TimeUnit.Milliseconds,
        RateUnit = TimeUnit.Milliseconds,            
        Reservoir = new Lazy<IReservoir>(() => new DefaultForwardDecayingReservoir(sampleSize:1028, alpha:0.015))
    };
}

Recording Metrics using an IMetrics instance

_metrics.Measure.Counter.Increment(AppMetricsRegistery.SampleCounter);
_metrics.Measure.Counter.Decrement(AppMetricsRegistery.SampleCounter);

_metrics.Measure.Gauge.SetValue(AppMetricsRegistery.Errors, () => 1);

_metrics.Provider.Histogram.Update(AppMetricsRegistery.SampleHistogram, 1);

_metrics.Provider.Meter.Mark(AppMetricsRegistery.SampleMeter, 1);

using(_metrics.Measure.Timer.Time(AppMetricsRegistery.SampleTimer))
{
    // Do something
}

Next Steps