Package org.apache.hadoop.fs.statistics.impl

Interface IOStatisticsStore

All Superinterfaces:

DurationTrackerFactory, IOStatistics, IOStatisticsAggregator, IOStatisticsSetters

All Known Implementing Classes:

ForwardingIOStatisticsStore

public interface IOStatisticsStore
extends IOStatistics, IOStatisticsSetters, IOStatisticsAggregator, DurationTrackerFactory

Interface of an IOStatistics store intended for use in classes which track statistics for reporting.

Field Summary

Fields inherited from interface org.apache.hadoop.fs.statistics.IOStatistics

MAX_UNSET_VALUE, MIN_UNSET_VALUE

Method Summary

Modifier and Type	Method	Description
void	addMaximumSample(java.lang.String key, long value)	Add a maximum sample: if greater than the current value, updates the value.
void	addMeanStatisticSample(java.lang.String key, long value)	Add a sample to the mean statistics.
void	addMinimumSample(java.lang.String key, long value)	Add a minimum sample: if less than the current value, updates the value.
default void	addSample(java.lang.String key, long count)	Add a statistics sample as a min, max and mean and count.
void	addTimedOperation(java.lang.String prefix, long durationMillis)	Add a duration to the min/mean/max statistics, using the given prefix and adding a suffix for each specific value.
void	addTimedOperation(java.lang.String prefix, java.time.Duration duration)	Add a duration to the min/mean/max statistics, using the given prefix and adding a suffix for each specific value.; increment tha counter whose name == prefix.
java.util.concurrent.atomic.AtomicLong	getCounterReference(java.lang.String key)	Get a reference to the atomic instance providing the value for a specific counter.
java.util.concurrent.atomic.AtomicLong	getGaugeReference(java.lang.String key)	Get a reference to the atomic instance providing the value for a specific gauge.
java.util.concurrent.atomic.AtomicLong	getMaximumReference(java.lang.String key)	Get a reference to the atomic instance providing the value for a specific maximum.
MeanStatistic	getMeanStatistic(java.lang.String key)	Get a reference to the atomic instance providing the value for a specific meanStatistic.
java.util.concurrent.atomic.AtomicLong	getMinimumReference(java.lang.String key)	Get a reference to the atomic instance providing the value for a specific minimum.
default long	incrementCounter(java.lang.String key)	Increment a counter by one.
long	incrementCounter(java.lang.String key, long value)	Increment a counter.
long	incrementGauge(java.lang.String key, long value)	Increment a gauge.
long	incrementMaximum(java.lang.String key, long value)	Increment a maximum.
long	incrementMinimum(java.lang.String key, long value)	Increment a minimum.
void	reset()	Reset all statistics.

Methods inherited from interface org.apache.hadoop.fs.statistics.DurationTrackerFactory

trackDuration, trackDuration

Methods inherited from interface org.apache.hadoop.fs.statistics.IOStatistics

counters, gauges, maximums, meanStatistics, minimums

Methods inherited from interface org.apache.hadoop.fs.statistics.IOStatisticsAggregator

aggregate

Methods inherited from interface org.apache.hadoop.fs.statistics.IOStatisticsSetters

setCounter, setGauge, setMaximum, setMeanStatistic, setMinimum

Method Detail

incrementCounter

default long incrementCounter(java.lang.String key)

Increment a counter by one. No-op if the counter is unknown.

Parameters:

key - statistics key

Returns:

old value or, if the counter is unknown: 0

incrementCounter

long incrementCounter(java.lang.String key,
                      long value)

Increment a counter. No-op if the counter is unknown. If the value is negative, it is ignored.

Parameters:

key - statistics key

value - value to increment

Returns:

the updated value or, if the counter is unknown: 0

incrementGauge

long incrementGauge(java.lang.String key,
                    long value)

Increment a gauge.

No-op if the gauge is unknown.

Parameters:

key - statistics key

value - value to increment

Returns:

new value or 0 if the key is unknown

incrementMaximum

long incrementMaximum(java.lang.String key,
                      long value)

Increment a maximum.

No-op if the maximum is unknown.

Parameters:

key - statistics key

value - value to increment

Returns:

new value or 0 if the key is unknown

incrementMinimum

long incrementMinimum(java.lang.String key,
                      long value)

Increment a minimum.

No-op if the minimum is unknown.

Parameters:

key - statistics key

value - value to increment

Returns:

new value or 0 if the key is unknown

addMinimumSample

void addMinimumSample(java.lang.String key,
                      long value)

Add a minimum sample: if less than the current value, updates the value.

No-op if the minimum is unknown.

Parameters:

key - statistics key

value - sample value

addMaximumSample

void addMaximumSample(java.lang.String key,
                      long value)

Add a maximum sample: if greater than the current value, updates the value.

No-op if the key is unknown.

Parameters:

key - statistics key

value - sample value

addMeanStatisticSample

void addMeanStatisticSample(java.lang.String key,
                            long value)

Add a sample to the mean statistics.

No-op if the key is unknown.

Parameters:

key - key

value - sample value.

reset

void reset()

Reset all statistics. Unsynchronized.

getCounterReference

java.util.concurrent.atomic.AtomicLong getCounterReference(java.lang.String key)

Get a reference to the atomic instance providing the value for a specific counter. This is useful if the value is passed around.

Parameters:

key - statistic name

Returns:

the reference

Throws:

java.lang.NullPointerException - if there is no entry of that name

getMaximumReference

java.util.concurrent.atomic.AtomicLong getMaximumReference(java.lang.String key)

Get a reference to the atomic instance providing the value for a specific maximum. This is useful if the value is passed around.

Parameters:

key - statistic name

Returns:

the reference

Throws:

java.lang.NullPointerException - if there is no entry of that name

getMinimumReference

java.util.concurrent.atomic.AtomicLong getMinimumReference(java.lang.String key)

Get a reference to the atomic instance providing the value for a specific minimum. This is useful if the value is passed around.

Parameters:

key - statistic name

Returns:

the reference

Throws:

java.lang.NullPointerException - if there is no entry of that name

getGaugeReference

java.util.concurrent.atomic.AtomicLong getGaugeReference(java.lang.String key)

Get a reference to the atomic instance providing the value for a specific gauge. This is useful if the value is passed around.

Parameters:

key - statistic name

Returns:

the reference

Throws:

java.lang.NullPointerException - if there is no entry of that name

getMeanStatistic

MeanStatistic getMeanStatistic(java.lang.String key)

Get a reference to the atomic instance providing the value for a specific meanStatistic. This is useful if the value is passed around.

Parameters:

key - statistic name

Returns:

the reference

Throws:

java.lang.NullPointerException - if there is no entry of that name

addTimedOperation

void addTimedOperation(java.lang.String prefix,
                       long durationMillis)

Add a duration to the min/mean/max statistics, using the given prefix and adding a suffix for each specific value. The update is not-atomic, even though each individual statistic is updated thread-safely. If two threads update the values simultaneously, at the end of each operation the state will be correct. It is only during the sequence that the statistics may be observably inconsistent.

Parameters:

prefix - statistic prefix

durationMillis - duration in milliseconds.

addTimedOperation

void addTimedOperation(java.lang.String prefix,
                       java.time.Duration duration)

Add a duration to the min/mean/max statistics, using the given prefix and adding a suffix for each specific value.; increment tha counter whose name == prefix. If any of the statistics are not registered, that part of the sequence will be omitted -the rest will proceed. The update is not-atomic, even though each individual statistic is updated thread-safely. If two threads update the values simultaneously, at the end of each operation the state will be correct. It is only during the sequence that the statistics may be observably inconsistent.

Parameters:

prefix - statistic prefix

duration - duration

addSample

default void addSample(java.lang.String key,
                       long count)

Add a statistics sample as a min, max and mean and count.

Parameters:

key - key to add.

count - count.