org.apache.htrace.core

Class Sampler

java.lang.Object

org.apache.htrace.core.Sampler

Direct Known Subclasses:

AlwaysSampler, CountSampler, NeverSampler, ProbabilitySampler

public abstract class Sampler
extends Object

Extremely simple callback to determine the frequency that an action should be performed.

For example, the next() function may look like this:

 
 public boolean next() {
   return Math.random() > 0.5;
 }
 
 

This would trace 50% of all gets, 75% of all puts and would not trace any other requests.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Sampler.Builder A Sampler builder.

Field Summary

Fields

Modifier and Type	Field and Description
static Sampler	ALWAYS
static Sampler	NEVER

Constructor Summary

Constructors

Constructor and Description
Sampler()

Method Summary

Modifier and Type	Method and Description
abstract boolean	next()

Methods inherited from class java.lang.Object

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

Field Detail

ALWAYS

public static final Sampler ALWAYS

NEVER

public static final Sampler NEVER

Constructor Detail

Sampler

public Sampler()

Method Detail

next

public abstract boolean next()