open-telemetry / open-telemetry/opentelemetry-java-contrib

Consistent sampling tests are flaky

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#2,050 0 comments 0 reactions 2 assignees View on GitHub

@PeterF778 is already working on this.

Since Jul 23, 2025.

bug component:consistent-sampling
Dominant language
Java
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Avg merge
2d 7h
Merged PRs (30d)
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Description

Component(s)

consistent-sampling

What happened?

https://scans.gradle.com/s/lkud6oenfjrhi
https://scans.gradle.com/s/2xvjyd25fvjng
Seems to be fairly easy to reproduce, change @Test to @RepeatedTest(100).
added

    System.err.println(originalNumberOfSpans + " " + observedPvalues + " " + samplingProbability);
    System.err.println(expectedProbabilities + " " + Arrays.toString(observedValues));

to https://github.com/open-telemetry/opentelemetry-java-contrib/blob/d18102b7ba05be4ade560b9c3cd8ebb736220f1c/consistent-sampling/src/test/java/io/opentelemetry/contrib/sampler/consistent/ConsistentProbabilityBasedSamplerTest.java#L143
for failing test it printed out

1000000 {4=37074, 5=12751} 0.05
{4=0.037500000000000006, 5=0.012499999999999997, NOT SAMPLED=0.95} [37074, 12751, 950175]
Component version

1.48.0

Log output

No response

Additional context

No response

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