org.apache.hadoop.metrics.util

Class MetricsTimeVaryingRate

java.lang.Object

org.apache.hadoop.metrics.util.MetricsBase

org.apache.hadoop.metrics.util.MetricsTimeVaryingRate

@InterfaceAudience.LimitedPrivate(value={"HDFS","MapReduce"})
public class MetricsTimeVaryingRate
extends MetricsBase

The MetricsTimeVaryingRate class is for a rate based metric that naturally varies over time (e.g. time taken to create a file). The rate is averaged at each interval heart beat (the interval is set in the metrics config file). This class also keeps track of the min and max rates along with a method to reset the min-max.

Field Summary

Fields inherited from class org.apache.hadoop.metrics.util.MetricsBase

NO_DESCRIPTION

Constructor Summary

Constructors

Constructor and Description
MetricsTimeVaryingRate(String nam, MetricsRegistry registry) Constructor - create a new metric
MetricsTimeVaryingRate(String nam, MetricsRegistry registry, String description) Constructor - create a new metric

Method Summary

Methods

Modifier and Type	Method and Description
long	getMaxTime() The max time for a single operation since the last reset resetMinMax()
long	getMinTime() The min time for a single operation since the last reset resetMinMax()
long	getPreviousIntervalAverageTime() The average rate of an operation in the previous interval
int	getPreviousIntervalNumOps() The number of operations in the previous interval
void	inc(int numOps, long time) Increment the metrics for numOps operations
void	inc(long time) Increment the metrics for one operation
void	pushMetric(MetricsRecord mr) Push the delta metrics to the mr.
void	resetMinMax() Reset the min max values

Methods inherited from class org.apache.hadoop.metrics.util.MetricsBase

getDescription, getName

Methods inherited from class java.lang.Object

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

Constructor Detail

MetricsTimeVaryingRate

public MetricsTimeVaryingRate(String nam,
                      MetricsRegistry registry,
                      String description)

Constructor - create a new metric

Parameters:

nam - the name of the metrics to be used to publish the metric

registry - - where the metrics object will be registered

MetricsTimeVaryingRate

public MetricsTimeVaryingRate(String nam,
                      MetricsRegistry registry)

Constructor - create a new metric

Parameters:

nam - the name of the metrics to be used to publish the metric

registry - - where the metrics object will be registered A description of MetricsBase.NO_DESCRIPTION is used

Method Detail

inc

public void inc(int numOps,
       long time)

Increment the metrics for numOps operations

Parameters:

numOps - - number of operations

time - - time for numOps operations

inc

public void inc(long time)

Increment the metrics for one operation

Parameters:

time - for one operation

pushMetric

public void pushMetric(MetricsRecord mr)

Push the delta metrics to the mr. The delta is since the last push/interval. Note this does NOT push to JMX (JMX gets the info via getPreviousIntervalAverageTime() and getPreviousIntervalNumOps()

Specified by:

pushMetric in class MetricsBase

Parameters:

mr -

getPreviousIntervalNumOps

public int getPreviousIntervalNumOps()

The number of operations in the previous interval

Returns:

- ops in prev interval

getPreviousIntervalAverageTime

public long getPreviousIntervalAverageTime()

The average rate of an operation in the previous interval

Returns:

- the average rate.

getMinTime

public long getMinTime()

The min time for a single operation since the last reset resetMinMax()

Returns:

min time for an operation

getMaxTime

public long getMaxTime()

The max time for a single operation since the last reset resetMinMax()

Returns:

max time for an operation

resetMinMax

public void resetMinMax()

Reset the min max values