voldemort.store.stats
Class Histogram

java.lang.Object
  voldemort.store.stats.Histogram

Deprecated. Use Tehuti Histograms instead...

@Deprecated
public class Histogram
extends java.lang.Object

A class for computing percentiles based on a simple histogram. The histogram starts at 0 and then has uniformly sized buckets. The number of buckets and width of each bucket is specified upon construction. Each bucket in the histogram "counts" the number of values inserted into the histogram that fall into the bucket's range. All interfaces for adding data to the histogram or querying the histogram for quantiles are synchronized to make this object threadsafe.

Constructor Summary

Histogram(int nBuckets, int step)
Deprecated. Initialize an empty histogram

Histogram(int nBuckets, int step, long resetIntervalMs)
Deprecated. Initialize an empty histogram

Method Summary

double	getAverage() Deprecated. Obtain the average of the data in the histogram Note: Caller is responsible for making sure 'sum' does not overflow within the reset interval
long	getQuantile(double quantile) Deprecated. Find the a value n such that the percentile falls within [ n, n + step).
void	insert(long data) Deprecated. Insert a value into the right bucket of the histogram.
void	reset() Deprecated. Reset the histogram back to empty (set all values to 0)

Methods inherited from class java.lang.Object

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

Constructor Detail

Histogram

public Histogram(int nBuckets,
                 int step,
                 long resetIntervalMs)

Deprecated.

Initialize an empty histogram

Parameters:

nBuckets - The number of buckets to use

step - The size of each bucket

Histogram

public Histogram(int nBuckets,
                 int step)

Deprecated.

Initialize an empty histogram

Parameters:

nBuckets - The number of buckets to use

step - The size (width) of each bucket

Method Detail

reset

public void reset()

Deprecated.

Reset the histogram back to empty (set all values to 0)

insert

public void insert(long data)

Deprecated.

Insert a value into the right bucket of the histogram. If the value is larger than any bound, insert into the last bucket. If the value is less than zero, then ignore it.

Parameters:

data - The value to insert into the histogram

getQuantile

public long getQuantile(double quantile)

Deprecated.

Find the a value n such that the percentile falls within [ n, n + step). This method does a LINEAR probe of the histogram. I.e., this method is O(nBuckets).

Parameters:

quantile - The percentile to find

Returns:

Lower bound associated with the percentile

getAverage

public double getAverage()

Deprecated.

Obtain the average of the data in the histogram Note: Caller is responsible for making sure 'sum' does not overflow within the reset interval

Returns:

the average over the current samples