internal static bool ShouldSample(SpanContext parentContext, string name, ISampler sampler, out SpanContext context, out SpanId parentSpanId)
{
var traceId = TraceId.Invalid;
var tracestate = Tracestate.Empty;
parentSpanId = SpanId.Invalid;
var parentOptions = TraceOptions.Default;
if (parentContext.IsValid)
{
traceId = parentContext.TraceId;
parentSpanId = parentContext.SpanId;
parentOptions = parentContext.TraceOptions;
}
else
{
traceId = TraceId.FromBytes(Guid.NewGuid().ToByteArray());
}
var result = parentOptions.IsSampled;
var spanId = SpanId.FromBytes(Guid.NewGuid().ToByteArray(), 8);
var traceOptions = TraceOptions.Default;
if (sampler != null)
{
var builder = TraceOptions.Builder(parentContext.TraceOptions);
result = sampler.ShouldSample(parentContext, traceId, spanId, name, null);
builder = builder.SetIsSampled(result);
traceOptions = builder.Build();
}
context = SpanContext.Create(traceId, spanId, traceOptions, parentContext.Tracestate);
return(result);
}
private static bool MakeSamplingDecision(
SpanContext parent,
string name,
ISampler sampler,
IEnumerable <ISpan> parentLinks,
ITraceId traceId,
ISpanId spanId,
ITraceParams activeTraceParams)
{
// If users set a specific sampler in the SpanBuilder, use it.
if (sampler != null)
{
return(sampler.ShouldSample(parent, traceId, spanId, name, parentLinks));
}
// Use the default sampler if this is a root Span or this is an entry point Span (has remote
// parent).
if (parent == null || !parent.IsValid)
{
return(activeTraceParams
.Sampler
.ShouldSample(parent, traceId, spanId, name, parentLinks));
}
// Parent is always different than null because otherwise we use the default sampler.
return(parent.TraceOptions.IsSampled || IsAnyParentLinkSampled(parentLinks));
}
private static bool MakeSamplingDecision(
SpanContext parent,
string name,
ISampler sampler,
IEnumerable <Link> parentLinks,
ActivityTraceId traceId,
ActivitySpanId spanId,
TracerConfiguration tracerConfiguration)
{
// If users set a specific sampler in the SpanBuilder, use it.
if (sampler != null)
{
return(sampler.ShouldSample(parent, traceId, spanId, name, parentLinks).IsSampled);
}
// Use the default sampler if this is a root Span or this is an entry point Span (has remote
// parent).
if (parent == null || !parent.IsValid)
{
return(tracerConfiguration
.Sampler
.ShouldSample(parent, traceId, spanId, name, parentLinks).IsSampled);
}
// Parent is always different than null because otherwise we use the default sampler.
return((parent.TraceOptions & ActivityTraceFlags.Recorded) != 0 || IsAnyParentLinkSampled(parentLinks));
}
// Applies the given sampler to NUM_SAMPLE_TRIES random traceId/spanId pairs.
private static void AssertSamplerSamplesWithProbability(
ISampler sampler, ISpanContext parent, IList <ISpan> parentLinks, double probability)
{
RandomGenerator random = new RandomGenerator(1234);
int count = 0; // Count of spans with sampling enabled
for (int i = 0; i < NUM_SAMPLE_TRIES; i++)
{
if (sampler.ShouldSample(
parent,
false,
TraceId.GenerateRandomId(random),
SpanId.GenerateRandomId(random),
SPAN_NAME,
parentLinks))
{
count++;
}
}
double proportionSampled = (double)count / NUM_SAMPLE_TRIES;
// Allow for a large amount of slop (+/- 10%) in number of sampled traces, to avoid flakiness.
Assert.True(proportionSampled <probability + 0.1 && proportionSampled> probability - 0.1);
}
public ISpan Start(ISpanBuilder spanBuilder)
{
if (spanBuilder == null)
{
throw new ArgumentNullException(nameof(spanBuilder));
}
var traceId = spanBuilder.References?.FirstOrDefault()?.SpanContext?.TraceId ?? Guid.NewGuid().ToString();
var spanId = Guid.NewGuid().ToString();
var baggage = new Baggage();
if (spanBuilder.References != null)
{
foreach (var reference in spanBuilder.References)
{
baggage.Merge(reference.SpanContext.Baggage);
}
}
var sampled = spanBuilder.Sampled ?? _sampler?.ShouldSample();
var spanContext = _spanContextFactory.Create(new SpanContextPackage(traceId, spanId, sampled.GetValueOrDefault(true), baggage, spanBuilder.References));
return(new Span(spanBuilder.OperationName, spanBuilder.StartTimestamp ?? DateTimeOffset.UtcNow, spanContext, _spanRecorder));
}
public Decision ShouldSample(SpanContext parentContext, ActivityTraceId traceId, ActivitySpanId spanId, string name,
IEnumerable <Link> links)
{
if (name == "/health")
{
return(new Decision(false));
}
return(_sampler.ShouldSample(parentContext, traceId, spanId, name, links));
}
// Applies the given sampler to NUM_SAMPLE_TRIES random traceId/spanId pairs.
private static void AssertSamplerSamplesWithProbability(
ISampler sampler, SpanContext parent, List <ILink> links, double probability)
{
var count = 0; // Count of spans with sampling enabled
for (var i = 0; i < NUM_SAMPLE_TRIES; i++)
{
if (sampler.ShouldSample(
parent,
ActivityTraceId.CreateRandom(),
ActivitySpanId.CreateRandom(),
SPAN_NAME,
links).IsSampled)
{
count++;
}
}
var proportionSampled = (double)count / NUM_SAMPLE_TRIES;
// Allow for a large amount of slop (+/- 10%) in number of sampled traces, to avoid flakiness.
Assert.True(proportionSampled <probability + 0.1 && proportionSampled> probability - 0.1);
}
internal static bool ShouldSample(SpanContext parentContext, string name, ISampler sampler, out SpanContext context, out ActivitySpanId parentSpanId)
{
ActivityTraceId traceId = default;
var tracestate = Tracestate.Empty;
parentSpanId = default;
var parentOptions = ActivityTraceFlags.None;
if (parentContext.IsValid)
{
traceId = parentContext.TraceId;
parentSpanId = parentContext.SpanId;
parentOptions = parentContext.TraceOptions;
}
else
{
traceId = ActivityTraceId.CreateRandom();
}
var result = (parentOptions & ActivityTraceFlags.Recorded) != 0;
var spanId = ActivitySpanId.CreateRandom();
var traceOptions = ActivityTraceFlags.None;
if (sampler != null)
{
traceOptions = parentContext.TraceOptions;
result = sampler.ShouldSample(parentContext, traceId, spanId, name, null);
if (result)
{
traceOptions |= ActivityTraceFlags.Recorded;
}
}
context = SpanContext.Create(traceId, spanId, traceOptions, parentContext.Tracestate);
return(result);
}
public void ProbabilitySampler_SampleBasedOnTraceId()
{
ISampler defaultProbability = ProbabilitySampler.Create(0.0001);
// This traceId will not be sampled by the ProbabilitySampler because the first 8 bytes as long
// is not less than probability * Long.MAX_VALUE;
ITraceId notSampledtraceId =
TraceId.FromBytes(
new byte[]
{
0x8F,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0,
0,
0,
0,
0,
0,
0,
0,
});
Assert.False(
defaultProbability.ShouldSample(
null,
notSampledtraceId,
SpanId.GenerateRandomId(random),
SPAN_NAME,
new List <ISpan>()));
// This traceId will be sampled by the ProbabilitySampler because the first 8 bytes as long
// is less than probability * Long.MAX_VALUE;
ITraceId sampledtraceId =
TraceId.FromBytes(
new byte[]
{
0x00,
0x00,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0,
0,
0,
0,
0,
0,
0,
0,
});
Assert.True(
defaultProbability.ShouldSample(
null,
sampledtraceId,
SpanId.GenerateRandomId(random),
SPAN_NAME,
new List <ISpan>()));
}
public void ProbabilitySampler_SampleBasedOnTraceId()
{
ISampler defaultProbability = ProbabilitySampler.Create(0.0001);
// This traceId will not be sampled by the ProbabilitySampler because the first 8 bytes as long
// is not less than probability * Long.MAX_VALUE;
var notSampledtraceId =
ActivityTraceId.CreateFromBytes(
new byte[]
{
0x8F,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0,
0,
0,
0,
0,
0,
0,
0,
});
Assert.False(
defaultProbability.ShouldSample(
null,
notSampledtraceId,
ActivitySpanId.CreateRandom(),
SPAN_NAME,
null).IsSampled);
// This traceId will be sampled by the ProbabilitySampler because the first 8 bytes as long
// is less than probability * Long.MAX_VALUE;
var sampledtraceId =
ActivityTraceId.CreateFromBytes(
new byte[]
{
0x00,
0x00,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0xFF,
0,
0,
0,
0,
0,
0,
0,
0,
});
Assert.True(
defaultProbability.ShouldSample(
null,
sampledtraceId,
ActivitySpanId.CreateRandom(),
SPAN_NAME,
null).IsSampled);
}
public ISpan Start(ISpanBuilder spanBuilder)
{
if (spanBuilder == null)
{
throw new ArgumentNullException(nameof(spanBuilder));
}
var traceId = spanBuilder.References?.FirstOrDefault()?.SpanContext?.TraceId ?? Guid.NewGuid().ToString();
var spanId = Guid.NewGuid().ToString();
Baggage baggage = new Baggage();
foreach (var reference in spanBuilder.References)
{
baggage.Merge(reference.SpanContext.Baggage);
}
var spanContext = _spanContextFactory.Create(new SpanContextPackage(traceId, spanId, _sampler.ShouldSample(), baggage));
return(new Span(spanBuilder.OperationName, spanContext, _spanQueue));
}