org.apache.hadoop.metrics2.util

类 MetricSampleQuantiles

java.lang.Object

org.apache.hadoop.metrics2.util.MetricSampleQuantiles

@InterfaceAudience.Private
public class MetricSampleQuantiles
extends Object

Implementation of the Cormode, Korn, Muthukrishnan, and Srivastava algorithm for streaming calculation of targeted high-percentile epsilon-approximate quantiles. This is a generalization of the earlier work by Greenwald and Khanna (GK), which essentially allows different error bounds on the targeted quantiles, which allows for far more efficient calculation of high-percentiles. See: Cormode, Korn, Muthukrishnan, and Srivastava "Effective Computation of Biased Quantiles over Data Streams" in ICDE 2005 Greenwald and Khanna, "Space-efficient online computation of quantile summaries" in SIGMOD 2001

构造器概要

构造器

构造器和说明
MetricSampleQuantiles(MetricQuantile[] quantiles)

方法概要

限定符和类型	方法和说明
void	clear() Resets the estimator, clearing out all previously inserted items
long	getCount() Returns the number of items that the estimator has processed
int	getSampleCount() Returns the number of samples kept by the estimator
void	insert(long v) Add a new value from the stream.
Map<MetricQuantile,Long>	snapshot() Get a snapshot of the current values of all the tracked quantiles.

从类继承的方法 java.lang.Object

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

构造器详细资料

MetricSampleQuantiles

public MetricSampleQuantiles(MetricQuantile[] quantiles)

方法详细资料

insert

public void insert(long v)

Add a new value from the stream.

参数:

v - the value to insert

snapshot

public Map<MetricQuantile,Long> snapshot()
                                  throws IOException

Get a snapshot of the current values of all the tracked quantiles.

返回:

snapshot of the tracked quantiles

抛出:

IOException - if no items have been added to the estimator

getCount

public long getCount()

Returns the number of items that the estimator has processed

返回:

count total number of items processed

getSampleCount

public int getSampleCount()

Returns the number of samples kept by the estimator

返回:

count current number of samples

clear

public void clear()

Resets the estimator, clearing out all previously inserted items