private void RunSamplerTest(
ISampler sampler,
int iterations,
float expectedAutoKeepRate,
float expectedUserKeepRate,
float acceptableVariancePercent)
{
var sampleSize = iterations;
var autoKeeps = 0;
var userKeeps = 0;
int seed = new Random().Next();
var idGenerator = new SpanIdGenerator(seed);
while (sampleSize-- > 0)
{
var traceId = idGenerator.CreateNew();
var span = GetMyServiceSpan(traceId);
var priority = sampler.GetSamplingPriority(span);
if (priority == SamplingPriorityValues.AutoKeep)
{
autoKeeps++;
}
else if (priority == SamplingPriorityValues.UserKeep)
{
userKeeps++;
}
}
// AUTO_KEEP
var autoKeepRate = autoKeeps / (float)iterations;
var autoKeepRateLowerLimit = expectedAutoKeepRate * (1 - acceptableVariancePercent);
var autoKeepRateUpperLimit = expectedAutoKeepRate * (1 + acceptableVariancePercent);
Assert.True(
autoKeepRate >= autoKeepRateLowerLimit && autoKeepRate <= autoKeepRateUpperLimit,
$"Sampling AUTO_KEEP rate expected between {autoKeepRateLowerLimit} and {autoKeepRateUpperLimit}, actual rate is {autoKeepRate}. Random generator seeded with {seed}.");
// USER_KEEP (aka MANUAL_KEEP)
var userKeepRate = userKeeps / (float)iterations;
var userKeepRateLowerLimit = expectedUserKeepRate * (1 - acceptableVariancePercent);
var userKeepRateUpperLimit = expectedUserKeepRate * (1 + acceptableVariancePercent);
Assert.True(
userKeepRate >= userKeepRateLowerLimit && userKeepRate <= userKeepRateUpperLimit,
$"Sampling USER_KEEP rate expected between {userKeepRateLowerLimit} and {userKeepRateUpperLimit}, actual rate is {userKeepRate}. Random generator seeded with {seed}.");
}