org.apache.hadoop.metrics2.lib
Class MutableStat

java.lang.Object
  org.apache.hadoop.metrics2.lib.MutableMetric
      org.apache.hadoop.metrics2.lib.MutableStat

Direct Known Subclasses:

MutableRate

@InterfaceAudience.Public
@InterfaceStability.Evolving
public class MutableStat
extends MutableMetric

A mutable metric with stats. Useful for keeping throughput/latency stats.

Constructor Summary

MutableStat(String name, String description, String sampleName, String valueName)
Construct a snapshot stat metric with extended stat off by default

MutableStat(String name, String description, String sampleName, String valueName, boolean extended)
Construct a sample statistics metric

Method Summary

void	add(long value) Add a snapshot to the metric
void	add(long numSamples, long sum) Add a number of samples and their sum to the running stat
void	resetMinMax() Reset the all time min max of the metric
void	setExtended(boolean extended) Set whether to display the extended stats (stdev, min/max etc.) or not
void	snapshot(MetricsRecordBuilder builder, boolean all) Get a snapshot of the metric

Methods inherited from class org.apache.hadoop.metrics2.lib.MutableMetric

changed, clearChanged, setChanged, snapshot

Methods inherited from class java.lang.Object

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

Constructor Detail

MutableStat

public MutableStat(String name,
                   String description,
                   String sampleName,
                   String valueName,
                   boolean extended)

Construct a sample statistics metric

Parameters:

name - of the metric

description - of the metric

sampleName - of the metric (e.g. "Ops")

valueName - of the metric (e.g. "Time", "Latency")

extended - create extended stats (stdev, min/max etc.) by default.

MutableStat

public MutableStat(String name,
                   String description,
                   String sampleName,
                   String valueName)

Construct a snapshot stat metric with extended stat off by default

Parameters:

name - of the metric

description - of the metric

sampleName - of the metric (e.g. "Ops")

valueName - of the metric (e.g. "Time", "Latency")

Method Detail

setExtended

public void setExtended(boolean extended)

Set whether to display the extended stats (stdev, min/max etc.) or not

Parameters:

extended - enable/disable displaying extended stats

add

public void add(long numSamples,
                long sum)

Add a number of samples and their sum to the running stat

Parameters:

numSamples - number of samples

sum - of the samples

add

public void add(long value)

Add a snapshot to the metric

Parameters:

value - of the metric

snapshot

public void snapshot(MetricsRecordBuilder builder,
                     boolean all)

Description copied from class: MutableMetric

Get a snapshot of the metric

Specified by:

snapshot in class MutableMetric

Parameters:

builder - the metrics record builder

all - if true, snapshot unchanged metrics as well

resetMinMax

public void resetMinMax()

Reset the all time min max of the metric