/// <summary>
/// Adds <see cref="AdaptiveSamplingTelemetryProcessor"/> to the <see cref="TelemetryProcessorChainBuilder" />
/// </summary>
/// <param name="builder">Instance of <see cref="TelemetryProcessorChainBuilder"/></param>
/// <param name="settings">Set of settings applicable to dynamic sampling percentage algorithm.</param>
/// <param name="callback">Callback invoked every time sampling percentage evaluation occurs.</param>
/// <return>Instance of <see cref="TelemetryProcessorChainBuilder"/>.</return>
public static TelemetryProcessorChainBuilder UseAdaptiveSampling(
this TelemetryProcessorChainBuilder builder,
SamplingPercentageEstimatorSettings settings,
AdaptiveSamplingPercentageEvaluatedCallback callback)
{
return builder.Use((next) => new AdaptiveSamplingTelemetryProcessor(settings, callback, next) { InitialSamplingPercentage = 100.0 / settings.EffectiveInitialSamplingRate });
}
public void MaxTelemetryItemsPerSecondAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.MaxTelemetryItemsPerSecond = -10;
Xunit.Assert.Equal(1E-12, settings.EffectiveMaxTelemetryItemsPerSecond, 12);
}
public void MovingAverageRatioSecondsAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.MovingAverageRatio = -3;
Xunit.Assert.Equal(0.25, settings.EffectiveMovingAverageRatio, 12);
}
/// <summary>
/// Initializes a new instance of the <see cref="SamplingPercentageEstimatorTelemetryProcessor"/> class.
/// <param name="settings">Dynamic sampling estimator settings.</param>
/// <param name="callback">Callback to invoke every time sampling percentage is evaluated.</param>
/// <param name="next">Next TelemetryProcessor in call chain.</param>
/// </summary>
public SamplingPercentageEstimatorTelemetryProcessor(
SamplingPercentageEstimatorSettings settings,
AdaptiveSamplingPercentageEvaluatedCallback callback,
ITelemetryProcessor next)
{
if (settings == null)
{
throw new ArgumentNullException("settings");
}
if (next == null)
{
throw new ArgumentNullException("next");
}
this.evaluationCallback = callback;
this.settings = settings;
this.next = next;
this.currenSamplingRate = settings.EffectiveInitialSamplingRate;
this.itemCount = new ExponentialMovingAverageCounter(settings.EffectiveMovingAverageRatio);
this.samplingPercentageLastChangeDateTime = DateTimeOffset.UtcNow;
// set evaluation interval to default value if it is negative or zero
this.evaluationInterval = this.settings.EffectiveEvaluationInterval;
// set up timer to run math to estimate sampling percentage
this.evaluationTimer = new Timer(
this.EstimateSamplingPercentage,
null,
this.evaluationInterval,
this.evaluationInterval);
}
public void SamplingPercentageIncreaseTimeoutSecondsAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.SamplingPercentageIncreaseTimeout = TimeSpan.Zero;
Assert.Equal(TimeSpan.FromMinutes(15), settings.EffectiveSamplingPercentageIncreaseTimeout);
}
public void EvaluationIntervalSecondsAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.EvaluationInterval = TimeSpan.Zero;
Assert.Equal(TimeSpan.FromSeconds(15), settings.EffectiveEvaluationInterval);
}
public void EvaluationIntervalSecondsAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.EvaluationInterval = TimeSpan.Zero;
Assert.AreEqual(TimeSpan.FromSeconds(15), settings.EffectiveEvaluationInterval);
}
public void MaxTelemetryItemsPerSecondAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.MaxTelemetryItemsPerSecond = -10;
Assert.AreEqual(1E-12, settings.EffectiveMaxTelemetryItemsPerSecond, 12);
}
public void MovingAverageRatioSecondsAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.MovingAverageRatio = -3;
Assert.AreEqual(0.25, settings.EffectiveMovingAverageRatio, 12);
}
public void SamplingPercentageIncreaseTimeoutSecondsAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.SamplingPercentageIncreaseTimeout = TimeSpan.Zero;
Assert.AreEqual(TimeSpan.FromMinutes(15), settings.EffectiveSamplingPercentageIncreaseTimeout);
}
public void MaxSamplingRateAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.MinSamplingPercentage = 200;
Assert.AreEqual(1, settings.EffectiveMaxSamplingRate);
settings.MinSamplingPercentage = -1;
Assert.AreEqual(1E8, settings.EffectiveMaxSamplingRate);
}
public void MaxSamplingRateAdjustedIfSetToIncorrectValue()
{
var settings = new SamplingPercentageEstimatorSettings();
settings.MinSamplingPercentage = 200;
Assert.Equal(1, settings.EffectiveMaxSamplingRate);
settings.MinSamplingPercentage = -1;
Assert.Equal(1E8, settings.EffectiveMaxSamplingRate);
}
/// <summary>
/// Initializes a new instance of the <see cref="AdaptiveSamplingTelemetryProcessor"/> class.
/// <param name="settings">Sampling percentage estimator settings.</param>
/// <param name="callback">Callback invoked every time sampling percentage is evaluated.</param>
/// <param name="next">Next TelemetryProcessor in call chain.</param>
/// </summary>
public AdaptiveSamplingTelemetryProcessor(
SamplingPercentageEstimatorSettings settings,
AdaptiveSamplingPercentageEvaluatedCallback callback,
ITelemetryProcessor next)
{
this.estimatorSettings = settings;
this.evaluationCallback = callback;
// make estimatortelemetry processor work after sampling was done
this.estimatorProcessor = new SamplingPercentageEstimatorTelemetryProcessor(settings, this.SamplingPercentageChanged, next);
this.samplingProcessor = new SamplingTelemetryProcessor(this.estimatorProcessor);
}
public void UseAdaptiveSamplingAddsAdaptiveSamplingProcessorToTheChainWithCorrectSettings()
{
SamplingPercentageEstimatorSettings settings = new SamplingPercentageEstimatorSettings
{
MaxSamplingPercentage = 13
};
AdaptiveSamplingPercentageEvaluatedCallback callback = (second, percentage, samplingPercentage, changed, estimatorSettings) => { };
var tc = new TelemetryConfiguration {
TelemetryChannel = new StubTelemetryChannel()
};
var channelBuilder = new TelemetryProcessorChainBuilder(tc);
channelBuilder.UseAdaptiveSampling(settings, callback);
channelBuilder.Build();
Assert.AreEqual(13, ((AdaptiveSamplingTelemetryProcessor)tc.TelemetryProcessorChain.FirstTelemetryProcessor).MaxSamplingPercentage);
}
private void SamplingPercentageChanged(
double afterSamplingTelemetryItemRatePerSecond,
double currentSamplingPercentage,
double newSamplingPercentage,
bool isSamplingPercentageChanged,
SamplingPercentageEstimatorSettings settings)
{
if (isSamplingPercentageChanged)
{
this.samplingProcessor.SamplingPercentage = newSamplingPercentage;
TelemetryChannelEventSource.Log.SamplingChanged(newSamplingPercentage);
}
if (this.evaluationCallback != null)
{
this.evaluationCallback(
afterSamplingTelemetryItemRatePerSecond,
currentSamplingPercentage,
newSamplingPercentage,
isSamplingPercentageChanged,
settings);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="SamplingPercentageEstimatorTelemetryProcessor"/> class.
/// <param name="settings">Dynamic sampling estimator settings.</param>
/// <param name="callback">Callback to invoke every time sampling percentage is evaluated.</param>
/// <param name="next">Next TelemetryProcessor in call chain.</param>
/// </summary>
public SamplingPercentageEstimatorTelemetryProcessor(
SamplingPercentageEstimatorSettings settings,
AdaptiveSamplingPercentageEvaluatedCallback callback,
ITelemetryProcessor next)
{
if (settings == null)
{
throw new ArgumentNullException("settings");
}
if (next == null)
{
throw new ArgumentNullException("next");
}
this.evaluationCallback = callback;
this.settings = settings;
this.next = next;
this.currenSamplingRate = settings.EffectiveInitialSamplingRate;
this.itemCount = new ExponentialMovingAverageCounter(settings.EffectiveMovingAverageRatio);
this.samplingPercentageLastChangeDateTime = DateTimeOffset.UtcNow;
// set evaluation interval to default value if it is negative or zero
this.evaluationInterval = this.settings.EffectiveEvaluationInterval;
// set up timer to run math to estimate sampling percentage
this.evaluationTimer = new Timer(
this.EstimateSamplingPercentage,
null,
this.evaluationInterval,
this.evaluationInterval);
}
private void TraceSamplingPercentageEvaluation(
double afterSamplingTelemetryItemRatePerSecond,
double currentSamplingPercentage,
double newSamplingPercentage,
bool isSamplingPercentageChanged,
SamplingPercentageEstimatorSettings settings)
{
Trace.WriteLine(string.Format(
"[Sampling% evaluation] {0}, Eps: {1}, Current %: {2}, New %: {3}, Changed: {4}",
DateTimeOffset.UtcNow.ToString("o"),
afterSamplingTelemetryItemRatePerSecond,
currentSamplingPercentage,
newSamplingPercentage,
isSamplingPercentageChanged));
}