Package io.honeycomb.beeline.tracing.sampling

Class DeterministicTraceSampler

java.lang.Object

io.honeycomb.beeline.tracing.sampling.DeterministicTraceSampler

All Implemented Interfaces:

TraceSampler<String>

public class DeterministicTraceSampler
extends Object
implements TraceSampler<String>

This TraceSampler allows for distributed sampling based on a common field such as a request or trace ID. It accepts a sample rate N and will deterministically sample 1/N events based on the target field. Hence, two or more processes can decide whether or not to sample related events without communication.

- A sample rate of 0 means the TraceSampler will never sample.
- A sampler rate of 1 means it will always samples.

This implementation is based on the implementations (and necessarily needs to be in line with) the other Beeline implementations.

Thread-safety

Instances of this class are thread-safe and can be shared.

See Also:

Go sampler, Nodejs sampler

Constructor Summary

Constructors

Constructor	Description
DeterministicTraceSampler(int sampleRate)	See the class level javadoc for an explanation of the sampleRate.

Method Summary

Modifier and Type	Method	Description
int	sample(String traceId)	Decides, based on the given traceId, whether to sample the current trace.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DeterministicTraceSampler

public DeterministicTraceSampler(int sampleRate)

See the class level javadoc for an explanation of the sampleRate.

Parameters:

sampleRate - to use - must not be negative.

Throws:

IllegalArgumentException - if sampleRate is negative.

IllegalStateException - if SHA-1 is not supported.

Method Detail

sample

public int sample(String traceId)

Decides, based on the given traceId, whether to sample the current trace. 0 if not, otherwise it returns the configured sampleRate.

Specified by:

sample in interface TraceSampler<String>

Parameters:

traceId - to use as input to the sampling algorithm.

Returns:

a decision of whether the trace is to be sampled.