public AdaptiveSampler(int targetSamplesPerInterval = DefaultTargetSamplesPerInterval, int targetSamplingIntervalInSeconds = DefaultTargetSamplingIntervalInSeconds, int?seed = null)
{
if (targetSamplesPerInterval < MinTargetSamplesPerInterval)
{
throw new ArgumentException(
$"invalid value provided for parameter; it must be at least {MinTargetSamplesPerInterval}",
nameof(targetSamplesPerInterval));
}
var rand = (seed.HasValue) ? new Random(seed.Value) : new Random();
//This .ctor does not trigger the start of the sampling interval timer
_state = new AdaptiveSamplerState(targetSamplesPerInterval, TimeSpan.FromSeconds(targetSamplingIntervalInSeconds), rand);
}
protected override void OnConfigurationUpdated(ConfigurationUpdateSource configurationUpdateSource)
{
if (configurationUpdateSource != ConfigurationUpdateSource.Server ||
!_configuration.DistributedTracingEnabled ||
!_configuration.SamplingTarget.HasValue)
{
return;
}
var samplingTarget = _configuration.SamplingTarget.Value;
if (samplingTarget < MinTargetSamplesPerInterval)
{
Log.Error(
$"invalid value specified in new server configuration; sampling_target must be at least {MinTargetSamplesPerInterval} but was {samplingTarget}. (defaulting to {DefaultTargetSamplesPerInterval})");
samplingTarget = DefaultTargetSamplesPerInterval;
}
var samplingInterval = TimeSpan.FromSeconds(_configuration.SamplingTargetPeriodInSeconds ?? DefaultTargetSamplingIntervalInSeconds);
//This .ctor will force the start of the sampling interval timer if it wasn't started previously
_state = new AdaptiveSamplerState(samplingTarget, samplingInterval, _state);
}
public AdaptiveSamplerState(int targetSamplesPerInterval, TimeSpan targetSamplesInterval, AdaptiveSamplerState state) : this(targetSamplesPerInterval, targetSamplesInterval, state._rand)
{
_candidatesSeenCurrentInterval = state._candidatesSeenCurrentInterval;
_candidatesSeenLastInterval = state._candidatesSeenLastInterval;
_candidatesSampledCurrentInterval = state._candidatesSampledCurrentInterval;
_nextIntervalStartTime = DateTimeOffset.UtcNow + TargetSamplesInterval;
}
