org.apache.hadoop.hbase.master.balancer

Class CandidateGenerator

java.lang.Object

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

Direct Known Subclasses:

FavoredStochasticBalancer.FavoredNodeLoadPicker, FavoredStochasticBalancer.FavoredNodeLocalityPicker, LoadCandidateGenerator, LocalityBasedCandidateGenerator, RegionReplicaCandidateGenerator, StochasticLoadBalancer.RandomCandidateGenerator

@InterfaceAudience.Private
abstract class CandidateGenerator
extends Object

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

Constructor Summary

Constructors

Constructor and Description
CandidateGenerator()

Method Summary

Modifier and Type	Method and Description
(package private) abstract BaseLoadBalancer.Cluster.Action	generate(BaseLoadBalancer.Cluster cluster)
protected BaseLoadBalancer.Cluster.Action	getAction(int fromServer, int fromRegion, int toServer, int toRegion)
(package private) List<Integer>	getRandomIterationOrder(int length) Returns a random iteration order of indexes of an array with size length
(package private) int	pickOtherRandomRack(BaseLoadBalancer.Cluster cluster, int rackIndex)
(package private) int	pickOtherRandomServer(BaseLoadBalancer.Cluster cluster, int serverIndex)
(package private) int	pickRandomRack(BaseLoadBalancer.Cluster cluster)
(package private) int	pickRandomRegion(BaseLoadBalancer.Cluster cluster, int server, double chanceOfNoSwap) From a list of regions pick a random one.
(package private) BaseLoadBalancer.Cluster.Action	pickRandomRegions(BaseLoadBalancer.Cluster cluster, int thisServer, int otherServer)
(package private) int	pickRandomServer(BaseLoadBalancer.Cluster cluster)

Methods inherited from class java.lang.Object

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

Constructor Detail

CandidateGenerator

CandidateGenerator()

Method Detail

generate

abstract BaseLoadBalancer.Cluster.Action generate(BaseLoadBalancer.Cluster cluster)

pickRandomRegion

int pickRandomRegion(BaseLoadBalancer.Cluster 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(BaseLoadBalancer.Cluster cluster)

pickRandomRack

int pickRandomRack(BaseLoadBalancer.Cluster cluster)

pickOtherRandomServer

int pickOtherRandomServer(BaseLoadBalancer.Cluster cluster,
                          int serverIndex)

pickOtherRandomRack

int pickOtherRandomRack(BaseLoadBalancer.Cluster cluster,
                        int rackIndex)

pickRandomRegions

BaseLoadBalancer.Cluster.Action pickRandomRegions(BaseLoadBalancer.Cluster cluster,
                                                  int thisServer,
                                                  int otherServer)

getAction

protected BaseLoadBalancer.Cluster.Action getAction(int fromServer,
                                                    int fromRegion,
                                                    int toServer,
                                                    int toRegion)

getRandomIterationOrder

List<Integer> getRandomIterationOrder(int length)

Returns a random iteration order of indexes of an array with size length