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 is 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.

  • Method Details

    • create

      public static Sampler create​(float probability)
      Parameters:
      probability - probability a request will result in a new trace. 0 means never sample, 1 means always sample. Minimum probability 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
      Parameters:
      traceIdIgnored - The trace ID to be decided on, can be ignored

    • toString

      public String toString()
      Overrides:
      toString in class Object