private async Task HandleContextAsync(HttpListenerContext listenerContext)
{
//request handling
using (_processingTimer.NewContext())
{
var time = ValueReader.GetCurrentValue(_processingTimer)
.Scale(TimeUnit.Milliseconds, TimeUnit.Milliseconds)
.Histogram.Percentile95;
if (time < _acceptableTimeOfService)
{
string paramString = listenerContext.Request.RawUrl;
if (listenerContext.Request.HttpMethod == "POST")
{
if (paramString.StartsWith("/process/"))
{
var result = ProcessImage(listenerContext);
using (var writer = new BinaryWriter(result.Item1.Response.OutputStream))
writer.Write(result.Item2);
return;
}
}
listenerContext.Response.StatusCode = (int)HttpStatusCode.BadRequest;
using (var writer = new StreamWriter(listenerContext.Response.OutputStream))
await writer.WriteLineAsync();
}
else
{
listenerContext.Response.StatusCode = (int)HttpStatusCode.ServiceUnavailable;
using (var writer = new StreamWriter(listenerContext.Response.OutputStream))
await writer.WriteLineAsync();
}
}
}
public SampleMetrics()
{
// define a simple gauge that will provide the instant value of this.someValue when requested
Metric.Gauge("SampleMetrics.DataValue", () => this.someValue, Unit.Custom("$"));
Metric.Gauge("Custom Ratio", () => ValueReader.GetCurrentValue(totalRequestsCounter).Count / ValueReader.GetCurrentValue(meter).FiveMinuteRate, Unit.Percent);
Metric.Advanced.Gauge("Ratio", () => new HitRatioGauge(meter, timer, m => m.OneMinuteRate), Unit.Percent);
}
public SampleMetrics(IMetrics metrics)
{
_metrics = metrics;
_concurrentRequestsCounter = _metrics.Advanced.Counter(SampleMetricsRegistry.Counters.ConcurrentRequestsCounter);
_histogramOfData = _metrics.Advanced.Histogram(SampleMetricsRegistry.Histograms.ResultsExample);
_meter = _metrics.Advanced.Meter(SampleMetricsRegistry.Meters.Requests);
_setCounter = _metrics.Advanced.Counter(SampleMetricsRegistry.Counters.SetCounter);
_setMeter = _metrics.Advanced.Meter(SampleMetricsRegistry.Meters.SetMeter);
_timer = _metrics.Advanced.Timer(SampleMetricsRegistry.Timers.Requests);
_totalRequestsCounter = _metrics.Advanced.Counter(SampleMetricsRegistry.Counters.Requests);
// define a simple gauge that will provide the instant value of someValue when requested
_metrics.Gauge(SampleMetricsRegistry.Gauges.DataValue, () => _someValue);
_metrics.Gauge(SampleMetricsRegistry.Gauges.CustomRatioGauge,
() => ValueReader.GetCurrentValue(_totalRequestsCounter).Count / ValueReader.GetCurrentValue(_meter).FiveMinuteRate);
_metrics.Advanced.Gauge(SampleMetricsRegistry.Gauges.Ratio, () => new HitRatioGauge(_meter, _timer, m => m.OneMinuteRate));
}
/// <summary>
/// Creates a new HitRatioGauge with externally tracked Meters, and uses the provided meter rate function to extract the value for the ratio.
/// </summary>
/// <param name="hitMeter">The numerator meter to use for the ratio.</param>
/// <param name="totalMeter">The denominator meter to use for the ratio.</param>
/// <param name="meterRateFunc">The function to extract a value from the MeterValue. Will be applied to both the numerator and denominator meters.</param>
public HitRatioGauge(Meter hitMeter, Meter totalMeter, Func <MeterValue, double> meterRateFunc)
: base(() => meterRateFunc(ValueReader.GetCurrentValue(hitMeter)), () => meterRateFunc(ValueReader.GetCurrentValue(totalMeter)))
{
}
/// <summary>
/// Creates a new HitPercentageGauge with externally tracked Meter and Timer, and uses the provided meter rate function
/// to extract the value for the percentage.
/// </summary>
/// <param name="hitMeter">The numerator meter to use.</param>
/// <param name="totalTimer">The denominator timer to use.</param>
/// <param name="meterRateFunc">
/// The function to extract a value from the MeterValue. Will be applied to both the numerator
/// and denominator meters.
/// </param>
public HitPercentageGauge(IMeter hitMeter, ITimer totalTimer, Func <MeterValue, double> meterRateFunc)
: base(() => meterRateFunc(ValueReader.GetCurrentValue(hitMeter)), () => meterRateFunc(ValueReader.GetCurrentValue(totalTimer).Rate))
{
}
