org.apache.hadoop.hbase.master.balancer

Class StochasticLoadBalancer.CandidateGenerator

java.lang.Object

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

Direct Known Subclasses:

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

Enclosing class:

StochasticLoadBalancer

abstract static class StochasticLoadBalancer.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)
protected List<Integer>	getRandomIterationOrder(int length) Returns a random iteration order of indexes of an array with size length
protected int	pickOtherRandomRack(BaseLoadBalancer.Cluster cluster, int rackIndex)
protected int	pickOtherRandomServer(BaseLoadBalancer.Cluster cluster, int serverIndex)
protected int	pickRandomRack(BaseLoadBalancer.Cluster cluster)
protected int	pickRandomRegion(BaseLoadBalancer.Cluster cluster, int server, double chanceOfNoSwap) From a list of regions pick a random one.
protected BaseLoadBalancer.Cluster.Action	pickRandomRegions(BaseLoadBalancer.Cluster cluster, int thisServer, int otherServer)
protected 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

protected int pickRandomRegion(BaseLoadBalancer.Cluster cluster,
                               int server,
                               double chanceOfNoSwap)

From a list of regions pick a random one. Null can be returned which StochasticLoadBalancer.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

protected int pickRandomServer(BaseLoadBalancer.Cluster cluster)

pickRandomRack

protected int pickRandomRack(BaseLoadBalancer.Cluster cluster)

pickOtherRandomServer

protected int pickOtherRandomServer(BaseLoadBalancer.Cluster cluster,
                                    int serverIndex)

pickOtherRandomRack

protected int pickOtherRandomRack(BaseLoadBalancer.Cluster cluster,
                                  int rackIndex)

pickRandomRegions

protected 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

protected List<Integer> getRandomIterationOrder(int length)

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