Package brave.sampler

Class CountingSampler

java.lang.Object

brave.sampler.Sampler

brave.sampler.CountingSampler

public final class CountingSampler
extends Sampler

This sampler is appropriate for low-traffic instrumentation (ex servers that each receive <100K requests), or those who do not provision random trace ids. It not appropriate for collectors as the sampling decision isn't idempotent (consistent based on trace id).

Implementation

This initializes a random bitset of size 100 (corresponding to 1% granularity). This means that it is accurate in units of 100 traces. At runtime, this loops through the bitset, returning the value according to a counter.

Field Summary

Fields inherited from class brave.sampler.Sampler

ALWAYS_SAMPLE, NEVER_SAMPLE

Method Summary

Modifier and Type	Method	Description
static Sampler	create(float rate)
boolean	isSampled(long traceIdIgnored)	loops over the pre-canned decisions, resetting to zero when it gets to the end.
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

create

public static Sampler create(float rate)

Parameters:

rate - 0 means never sample, 1 means always sample. Otherwise minimum sample rate is 0.01, or 1% of traces

isSampled

public boolean isSampled(long traceIdIgnored)

loops over the pre-canned decisions, resetting to zero when it gets to the end.

Specified by:

isSampled in class Sampler

toString

public String toString()

Overrides:

toString in class Object