/// <summary>
/// Replace <see cref="Sampler"/> with a new instance when parameters are updated.
/// </summary>
/// <param name="response">Response which contains either a <see cref="ProbabilisticSampler"/>
/// or <see cref="RateLimitingSampler"/>.</param>
private void UpdateRateLimitingOrProbabilisticSampler(SamplingStrategyResponse response)
{
ISampler sampler;
if (response.ProbabilisticSampling != null)
{
ProbabilisticSamplingStrategy strategy = response.ProbabilisticSampling;
sampler = new ProbabilisticSampler(strategy.SamplingRate);
}
else if (response.RateLimitingSampling != null)
{
RateLimitingSamplingStrategy strategy = response.RateLimitingSampling;
sampler = new RateLimitingSampler(strategy.MaxTracesPerSecond);
}
else
{
_metrics.SamplerParsingFailure.Inc(1);
_logger.LogError("No strategy present in response. Not updating sampler.");
return;
}
lock (_lock)
{
if (!Sampler.Equals(sampler))
{
Sampler.Close();
Sampler = sampler;
_metrics.SamplerUpdated.Inc(1);
}
}
}
/// <summary>
/// Updates the probabilistic and lowerBound samplers.
/// </summary>
/// <param name="samplingRate">The sampling rate for probabilistic sampling.</param>
/// <param name="lowerBound">The lower bound limit for lower bound sampling.</param>
/// <returns><c>true</c>, if any samplers were updated.</returns>
public virtual bool Update(double samplingRate, double lowerBound)
{
lock (_lock)
{
var isUpdated = false;
if (samplingRate != _probabilisticSampler.SamplingRate)
{
_probabilisticSampler.Close();
_probabilisticSampler = new ProbabilisticSampler(samplingRate);
var newTags = new Dictionary <string, object>();
foreach (var oldTag in _tags)
{
newTags[oldTag.Key] = oldTag.Value;
}
newTags[Constants.SamplerParamTagKey] = samplingRate;
_tags = newTags;
isUpdated = true;
}
if (lowerBound != _lowerBoundSampler.MaxTracesPerSecond)
{
_lowerBoundSampler.Close();
_lowerBoundSampler = new RateLimitingSampler(lowerBound);
isUpdated = true;
}
return(isUpdated);
}
}
public GuaranteedThroughputSampler(double samplingRate, double lowerBound)
{
_tags = new Dictionary <string, object> {
{ Constants.SamplerTypeTagKey, Type },
{ Constants.SamplerParamTagKey, samplingRate }
};
_probabilisticSampler = new ProbabilisticSampler(samplingRate);
_lowerBoundSampler = new RateLimitingSampler(lowerBound);
}
internal PerOperationSampler(
int maxOperations,
Dictionary <string, GuaranteedThroughputSampler> samplers,
ProbabilisticSampler probabilisticSampler,
double lowerBound,
ILoggerFactory loggerFactory)
{
MaxOperations = maxOperations;
OperationNameToSampler = samplers ?? new Dictionary <string, GuaranteedThroughputSampler>();
DefaultSampler = probabilisticSampler ?? throw new ArgumentNullException(nameof(probabilisticSampler));
LowerBound = lowerBound;
_logger = loggerFactory?.CreateLogger <PerOperationSampler>() ?? throw new ArgumentNullException(nameof(loggerFactory));
}
public RemoteControlledSampler Build()
{
if (LoggerFactory == null)
{
LoggerFactory = NullLoggerFactory.Instance;
}
if (InitialSampler == null)
{
InitialSampler = new ProbabilisticSampler();
}
if (Metrics == null)
{
Metrics = new MetricsImpl(NoopMetricsFactory.Instance);
}
return(new RemoteControlledSampler(this));
}
/// <summary>
/// Updates the <see cref="GuaranteedThroughputSampler"/> for each operation.
/// </summary>
/// <param name="strategies">The parameters for operation sampling.</param>
/// <returns><c>true</c>, if any samplers were updated.</returns>
public bool Update(OperationSamplingParameters strategies)
{
lock (_lock)
{
var isUpdated = false;
LowerBound = strategies.DefaultLowerBoundTracesPerSecond;
ProbabilisticSampler defaultSampler = new ProbabilisticSampler(strategies.DefaultSamplingProbability);
if (!defaultSampler.Equals(DefaultSampler))
{
DefaultSampler.Close();
DefaultSampler = defaultSampler;
isUpdated = true;
}
foreach (var strategy in strategies.PerOperationStrategies)
{
var operation = strategy.Operation;
var samplingRate = strategy.ProbabilisticSampling.SamplingRate;
if (OperationNameToSampler.TryGetValue(operation, out var sampler))
{
isUpdated = sampler.Update(samplingRate, LowerBound) || isUpdated;
}
else
{
if (OperationNameToSampler.Count < MaxOperations)
{
sampler = new GuaranteedThroughputSampler(samplingRate, LowerBound);
OperationNameToSampler[operation] = sampler;
isUpdated = true;
}
else
{
_logger.LogInformation("Exceeded the maximum number of operations {maxOperations} for per operations sampling", MaxOperations);
}
}
}
return(isUpdated);
}
}
