org.apache.hadoop.hbase.master.balancer

Class LocalityBasedCostFunction

java.lang.Object

org.apache.hadoop.hbase.master.balancer.CostFunction

org.apache.hadoop.hbase.master.balancer.LocalityBasedCostFunction

Direct Known Subclasses:

RackLocalityCostFunction, ServerLocalityCostFunction

@InterfaceAudience.Private
abstract class LocalityBasedCostFunction
extends CostFunction

Compute a cost of a potential cluster configuration based upon where HStoreFiles are located.

Field Summary

Fields

Modifier and Type	Field and Description
private double	bestLocality
private double	locality
private BalancerClusterState.LocalityType	type

Fields inherited from class org.apache.hadoop.hbase.master.balancer.CostFunction

cluster, COST_EPSILON

Constructor Summary

Constructors

Constructor and Description
LocalityBasedCostFunction(org.apache.hadoop.conf.Configuration conf, BalancerClusterState.LocalityType type, String localityCostKey, float defaultLocalityCost)

Method Summary

Modifier and Type	Method and Description
protected double	cost()
private int	getMostLocalEntityForRegion(int region)
private double	getWeightedLocality(int region, int entity)
(package private) void	prepare(BalancerClusterState cluster) Called once per LB invocation to give the cost function to initialize it's state, and perform any costly calculation.
(package private) abstract int	regionIndexToEntityIndex(int region) Maps region to the current entity (server or rack) on which it is stored
protected void	regionMoved(int region, int oldServer, int newServer)
void	updateWeight(double[] weights) Add the cost of this cost function to the weight of the candidate generator that is optimized for this cost function.

Methods inherited from class org.apache.hadoop.hbase.master.balancer.CostFunction

getMultiplier, isNeeded, postAction, scale, setMultiplier

Methods inherited from class java.lang.Object

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

Field Detail

type

private final BalancerClusterState.LocalityType type

bestLocality

private double bestLocality

locality

private double locality

Constructor Detail

LocalityBasedCostFunction

LocalityBasedCostFunction(org.apache.hadoop.conf.Configuration conf,
                          BalancerClusterState.LocalityType type,
                          String localityCostKey,
                          float defaultLocalityCost)

Method Detail

regionIndexToEntityIndex

abstract int regionIndexToEntityIndex(int region)

Maps region to the current entity (server or rack) on which it is stored

prepare

void prepare(BalancerClusterState cluster)

Description copied from class: CostFunction

Called once per LB invocation to give the cost function to initialize it's state, and perform any costly calculation.

Overrides:

prepare in class CostFunction

regionMoved

protected void regionMoved(int region,
                           int oldServer,
                           int newServer)

Overrides:

regionMoved in class CostFunction

cost

protected final double cost()

Specified by:

cost in class CostFunction

getMostLocalEntityForRegion

private int getMostLocalEntityForRegion(int region)

getWeightedLocality

private double getWeightedLocality(int region,
                                   int entity)

updateWeight

public final void updateWeight(double[] weights)

Description copied from class: CostFunction

Add the cost of this cost function to the weight of the candidate generator that is optimized for this cost function. By default it is the RandomCandiateGenerator for a cost function. Called once per init or after postAction.

Overrides:

updateWeight in class CostFunction

Parameters:

weights - the weights for every generator.