org.apache.storm.metrics.hdrhistogram

Class HistogramMetric

java.lang.Object

org.apache.storm.metrics.hdrhistogram.HistogramMetric

All Implemented Interfaces:

IMetric

public class HistogramMetric
extends Object
implements IMetric

A metric wrapping an HdrHistogram.

Constructor Summary

Constructors

Constructor and Description
HistogramMetric(int numberOfSignificantValueDigits)
HistogramMetric(Long highestTrackableValue, int numberOfSignificantValueDigits)
HistogramMetric(Long lowestDiscernibleValue, Long highestTrackableValue, int numberOfSignificantValueDigits) (From the Constructor of Histogram) Construct a Histogram given the Lowest and Highest values to be tracked and a number of significant decimal digits.

Method Summary

Modifier and Type	Method and Description
Object	getValueAndReset() Get value and reset.
void	recordValue(long val)

Methods inherited from class java.lang.Object

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

Constructor Detail

HistogramMetric

public HistogramMetric(int numberOfSignificantValueDigits)

HistogramMetric

public HistogramMetric(Long highestTrackableValue,
                       int numberOfSignificantValueDigits)

HistogramMetric

public HistogramMetric(Long lowestDiscernibleValue,
                       Long highestTrackableValue,
                       int numberOfSignificantValueDigits)

(From the Constructor of Histogram) Construct a Histogram given the Lowest and Highest values to be tracked and a number of significant decimal digits. Providing a lowestDiscernibleValue is useful is situations where the units used for the histogram’s values are much smaller that the minimal accuracy required. E.g. when tracking time values stated in nanosecond units, where the minimal accuracy required is a microsecond, the proper value for lowestDiscernibleValue would be 1000.

Parameters:

lowestDiscernibleValue - The lowest value that can be discerned (distinguished from 0) by the histogram. Must be a positive integer that is >= 1. May be internally rounded down to nearest power of 2 (if null 1 is used).

highestTrackableValue - The highest value to be tracked by the histogram. Must be a positive integer that is >= (2 * lowestDiscernibleValue). (if null 2 * lowestDiscernibleValue is used and auto-resize is enabled)

numberOfSignificantValueDigits - Specifies the precision to use. This is the number of significant decimal digits to which the histogram will maintain value resolution and separation. Must be a non-negative integer between 0 and 5.

Method Detail

recordValue

public void recordValue(long val)

getValueAndReset

public Object getValueAndReset()

Description copied from interface: IMetric

Get value and reset.

Specified by:

getValueAndReset in interface IMetric

Returns:

an object that will be sent sent to IMetricsConsumer#handleDataPoints(org.apache.storm.metric.api.IMetricsConsumer .TaskInfo, java.util.Collection). If null is returned nothing will be sent. If this value can be reset, like with a counter, a side effect of calling this should be that the value is reset.