org.apache.pig.impl.util

Class SpillableMemoryManager

java.lang.Object

org.apache.pig.impl.util.SpillableMemoryManager

All Implemented Interfaces:

EventListener, NotificationListener

public class SpillableMemoryManager
extends Object
implements NotificationListener

This class Tracks the tenured pool and a list of Spillable objects. When memory gets low, this class will start requesting Spillable objects to free up memory.

Low memory is defined as more than 50% of the tenured pool being allocated. Spillable objects are tracked using WeakReferences so that the objects can be GCed even though this class has a reference to them.

Method Summary

Modifier and Type	Method and Description
void	clearSpillables()
void	configure(org.apache.hadoop.conf.Configuration conf)
static SpillableMemoryManager	getInstance()
void	handleNotification(Notification n, Object o)
void	registerSpillable(Spillable s) Register a spillable to be tracked.
static void	staticDataCleanup()

Methods inherited from class java.lang.Object

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

Method Detail

staticDataCleanup

public static void staticDataCleanup()

getInstance

public static SpillableMemoryManager getInstance()

configure

public void configure(org.apache.hadoop.conf.Configuration conf)

handleNotification

public void handleNotification(Notification n,
                               Object o)

Specified by:

handleNotification in interface NotificationListener

clearSpillables

public void clearSpillables()

registerSpillable

public void registerSpillable(Spillable s)

Register a spillable to be tracked. No need to unregister, the tracking will stop when the spillable is GCed.

Parameters:

s - the spillable to track.