Package org.apache.ignite.internal.processors.metric.impl

Class HitRateMetric

java.lang.Object

org.apache.ignite.internal.processors.metric.AbstractMetric

org.apache.ignite.internal.processors.metric.impl.HitRateMetric

All Implemented Interfaces:

LongMetric, Metric

public class HitRateMetric
extends AbstractMetric
implements LongMetric

Accumulates approximate hit rate statistics. Calculates number of hits in last rateTimeInterval milliseconds. Algorithm is based on circular array of size hit counters, each is responsible for last corresponding time interval of rateTimeInterval/size milliseconds. Resulting number of hits is sum of all counters.

Implementation is nonblocking and protected from hits loss. Maximum relative error is 1/size. 2^55 - 1 hits per interval can be accumulated without numeric overflow.

Field Summary

Fields

Modifier and Type	Field	Description
static int	DFLT_SIZE	Default counters array size.

Constructor Summary

Constructors

Constructor	Description
HitRateMetric(String name, @Nullable String desc, long rateTimeInterval, int size)

Method Summary

Modifier and Type	Method	Description
void	add(long x)	Adds x to the metric.
void	increment()	Adds 1 to the metric.
long	rateTimeInterval()
void	reset()	Resets metric state.
void	reset(long rateTimeInterval)	Resets metric with the new parametes.
void	reset(long rateTimeInterval, int size)	Resets metric with the new parameters.
long	value()

Methods inherited from class org.apache.ignite.internal.processors.metric.AbstractMetric

description, equals, hashCode, name

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.ignite.spi.metric.LongMetric

getAsString

Methods inherited from interface org.apache.ignite.spi.metric.Metric

description, name

Field Detail

DFLT_SIZE

public static final int DFLT_SIZE

Default counters array size.

See Also:

Constant Field Values

Constructor Detail

HitRateMetric

public HitRateMetric(String name,
                     @Nullable
                     @Nullable String desc,
                     long rateTimeInterval,
                     int size)

Parameters:

name - Name.

desc - Description.

rateTimeInterval - Rate time interval in milliseconds.

size - Counters array size.

Method Detail

reset

public void reset()

Resets metric state.

Specified by:

reset in interface Metric

reset

public void reset(long rateTimeInterval)

Resets metric with the new parametes.

Parameters:

rateTimeInterval - New rate time interval.

reset

public void reset(long rateTimeInterval,
                  int size)

Resets metric with the new parameters.

Parameters:

rateTimeInterval - New rate time interval.

size - New counters array size.

add

public void add(long x)

Adds x to the metric.

Parameters:

x - Value to be added.

increment

public void increment()

Adds 1 to the metric.

value

public long value()

Specified by:

value in interface LongMetric

Returns:

Value of the metric.

rateTimeInterval

public long rateTimeInterval()

Returns:

Rate time interval in milliseconds.