Package org.apache.hadoop.hdfs.server.diskbalancer.datamodel

Class DiskBalancerVolumeSet

java.lang.Object

org.apache.hadoop.hdfs.server.diskbalancer.datamodel.DiskBalancerVolumeSet

public class DiskBalancerVolumeSet
extends java.lang.Object

DiskBalancerVolumeSet is a collection of storage devices on the data node which are of similar StorageType.

Constructor Summary

Constructors

Constructor	Description
DiskBalancerVolumeSet()	Constructs Empty DiskNBalanceVolumeSet.
DiskBalancerVolumeSet(boolean isTransient)	Constructs a DiskBalancerVolumeSet.
DiskBalancerVolumeSet(DiskBalancerVolumeSet volumeSet)	Constructs a new DiskBalancerVolumeSet.

Method Summary

Modifier and Type	Method	Description
void	addVolume(DiskBalancerVolume volume)	adds a given volume into this volume set.
void	computeVolumeDataDensity()	Computes Volume Data Density.
double	getIdealUsed()	Gets the idealUsed for this volume set.
java.lang.String	getSetID()	Get Volume Set ID.
java.util.TreeSet<DiskBalancerVolume>	getSortedQueue()
java.lang.String	getStorageType()	Get Storage Type.
int	getVolumeCount()	Returns the number of volumes in the Volume Set.
java.util.List<DiskBalancerVolume>	getVolumes()	Returns a list diskVolumes that are part of this volume set.
boolean	isBalancingNeeded(double thresholdPercentage)	Computes whether we need to do any balancing on this volume Set at all.
boolean	isTransient()	Tells us if this volumeSet is transient.
void	removeVolume(DiskBalancerVolume volume)	Remove a volume from the current set.
void	setSetID(java.lang.String volID)	Set VolumeSet ID.
void	setStorageType(java.lang.String typeOfStorage)	Set Storage Type.
void	setTransient(boolean transientValue)	Set the transient properties for this volumeSet.

Methods inherited from class java.lang.Object

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

Constructor Detail

DiskBalancerVolumeSet

public DiskBalancerVolumeSet()

Constructs Empty DiskNBalanceVolumeSet. This is needed by jackson

DiskBalancerVolumeSet

public DiskBalancerVolumeSet(boolean isTransient)

Constructs a DiskBalancerVolumeSet.

Parameters:

isTransient - - boolean

DiskBalancerVolumeSet

public DiskBalancerVolumeSet(DiskBalancerVolumeSet volumeSet)

Constructs a new DiskBalancerVolumeSet.

Method Detail

isTransient

public boolean isTransient()

Tells us if this volumeSet is transient.

Returns:

- true or false

setTransient

public void setTransient(boolean transientValue)

Set the transient properties for this volumeSet.

Parameters:

transientValue - - Boolean

computeVolumeDataDensity

public void computeVolumeDataDensity()

Computes Volume Data Density. Adding a new volume changes the volumeDataDensity for all volumes. So we throw away our priority queue and recompute everything. we discard failed volumes from this computation. totalCapacity = totalCapacity of this volumeSet totalUsed = totalDfsUsed for this volumeSet idealUsed = totalUsed / totalCapacity dfsUsedRatio = dfsUsedOnAVolume / Capacity On that Volume volumeDataDensity = idealUsed - dfsUsedRatio

getVolumeCount

public int getVolumeCount()

Returns the number of volumes in the Volume Set.

Returns:

int

getStorageType

public java.lang.String getStorageType()

Get Storage Type.

Returns:

String

setStorageType

public void setStorageType(java.lang.String typeOfStorage)

Set Storage Type.

Parameters:

typeOfStorage - -- StorageType

addVolume

public void addVolume(DiskBalancerVolume volume)
               throws java.lang.Exception

adds a given volume into this volume set.

Parameters:

volume - - volume to add.

Throws:

java.lang.Exception

getVolumes

public java.util.List<DiskBalancerVolume> getVolumes()

Returns a list diskVolumes that are part of this volume set.

Returns:

List

getSortedQueue

public java.util.TreeSet<DiskBalancerVolume> getSortedQueue()

isBalancingNeeded

public boolean isBalancingNeeded(double thresholdPercentage)

Computes whether we need to do any balancing on this volume Set at all. It checks if any disks are out of threshold value

Parameters:

thresholdPercentage - - threshold - in percentage

Returns:

true if balancing is needed false otherwise.

removeVolume

public void removeVolume(DiskBalancerVolume volume)

Remove a volume from the current set. This call does not recompute the volumeDataDensity. It has to be done manually after this call.

Parameters:

volume - - Volume to remove

getSetID

public java.lang.String getSetID()

Get Volume Set ID.

Returns:

String

setSetID

public void setSetID(java.lang.String volID)

Set VolumeSet ID.

Parameters:

volID - String

getIdealUsed

public double getIdealUsed()

Gets the idealUsed for this volume set.