Package org.apache.hadoop.hbase.master.balancer

Class CandidateGenerator

java.lang.Object

org.apache.hadoop.hbase.master.balancer.CandidateGenerator

Direct Known Subclasses:

CacheAwareLoadBalancer.CacheAwareCandidateGenerator, FavoredStochasticBalancer.FavoredNodeLoadPicker, FavoredStochasticBalancer.FavoredNodeLocalityPicker, LoadCandidateGenerator, LocalityBasedCandidateGenerator, RandomCandidateGenerator, RegionReplicaCandidateGenerator

@Private
abstract class CandidateGenerator
extends Object

Generates a candidate action to be applied to the cluster for cost function search

Constructor Summary

Constructors

Constructor	Description
CandidateGenerator()

Method Summary

Modifier and Type	Method	Description
(package private) abstract BalanceAction	generate(BalancerClusterState cluster)
protected BalanceAction	getAction(int fromServer, int fromRegion, int toServer, int toRegion)
(package private) int	pickOtherRandomRack(BalancerClusterState cluster, int rackIndex)
(package private) int	pickOtherRandomServer(BalancerClusterState cluster, int serverIndex)
(package private) int	pickRandomRack(BalancerClusterState cluster)
(package private) int	pickRandomRegion(BalancerClusterState cluster, int server, double chanceOfNoSwap)	From a list of regions pick a random one.
(package private) BalanceAction	pickRandomRegions(BalancerClusterState cluster, int thisServer, int otherServer)
(package private) int	pickRandomServer(BalancerClusterState cluster)

Methods inherited from class java.lang.Object

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

Constructor Details

CandidateGenerator

CandidateGenerator()

Method Details

generate

abstract BalanceAction generate(BalancerClusterState cluster)

pickRandomRegion

int pickRandomRegion(BalancerClusterState cluster,
 int server,
 double chanceOfNoSwap)

From a list of regions pick a random one. Null can be returned which BaseLoadBalancer.balanceCluster(Map) recognize as signal to try a region move rather than swap.

Parameters:

cluster - The state of the cluster

server - index of the server

chanceOfNoSwap - Chance that this will decide to try a move rather than a swap.

Returns:

a random RegionInfo or null if an asymmetrical move is suggested.

pickRandomServer

int pickRandomServer(BalancerClusterState cluster)

pickRandomRack

int pickRandomRack(BalancerClusterState cluster)

pickOtherRandomServer

int pickOtherRandomServer(BalancerClusterState cluster,
 int serverIndex)

pickOtherRandomRack

int pickOtherRandomRack(BalancerClusterState cluster,
 int rackIndex)

pickRandomRegions

BalanceAction pickRandomRegions(BalancerClusterState cluster,
 int thisServer,
 int otherServer)

getAction

protected BalanceAction getAction(int fromServer,
 int fromRegion,
 int toServer,
 int toRegion)