org.infinispan.distribution.ch

Class ReplicatedConsistentHashFactory

java.lang.Object

org.infinispan.distribution.ch.ReplicatedConsistentHashFactory

All Implemented Interfaces:

ConsistentHashFactory<ReplicatedConsistentHash>

public class ReplicatedConsistentHashFactory
extends Object
implements ConsistentHashFactory<ReplicatedConsistentHash>

Factory for ReplicatedConsistentHash.

Since:

5.2

Author:

Dan Berindei, anistor@redhat.com

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ReplicatedConsistentHashFactory.Externalizer

Constructor Summary

Constructors

Constructor and Description
ReplicatedConsistentHashFactory()

Method Summary

Methods

Modifier and Type	Method and Description
ReplicatedConsistentHash	create(Hash hashFunction, int numOwners, int numSegments, List<Address> members, Map<Address,Float> capacityFactors) Create a new consistent hash instance.
ReplicatedConsistentHash	rebalance(ReplicatedConsistentHash baseCH) Create a new consistent hash instance, based on an existing instance, but "balanced" according to the implementation's rules.
ReplicatedConsistentHash	union(ReplicatedConsistentHash ch1, ReplicatedConsistentHash ch2) Creates a union of two compatible ConsistentHashes (use the same hashing function and have the same configuration parameters).
ReplicatedConsistentHash	updateMembers(ReplicatedConsistentHash baseCH, List<Address> newMembers, Map<Address,Float> actualCapacityFactors) Create a new consistent hash instance, based on an existing instance, but with a new list of members.

Methods inherited from class java.lang.Object

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

Constructor Detail

ReplicatedConsistentHashFactory

public ReplicatedConsistentHashFactory()

Method Detail

create

public ReplicatedConsistentHash create(Hash hashFunction,
                              int numOwners,
                              int numSegments,
                              List<Address> members,
                              Map<Address,Float> capacityFactors)

Description copied from interface: ConsistentHashFactory

Create a new consistent hash instance.

Specified by:

create in interface ConsistentHashFactory<ReplicatedConsistentHash>

Parameters:

hashFunction - The hash function to use on top of the keys' own hashCode() implementation.

numOwners - The ideal number of owners for each key. The created consistent hash can have more or less owners, but each key will have at least one owner.

numSegments - Number of hash-space segments. The implementation may round up the number of segments for performance, or may ignore the parameter altogether.

members - A list of addresses representing the new cache members.

capacityFactors - The capacity factor of each member. Determines the relative capacity of each node compared to the others. The implementation may ignore this parameter. If null, all the members are assumed to have a capacity factor of 1.

updateMembers

public ReplicatedConsistentHash updateMembers(ReplicatedConsistentHash baseCH,
                                     List<Address> newMembers,
                                     Map<Address,Float> actualCapacityFactors)

Description copied from interface: ConsistentHashFactory

Create a new consistent hash instance, based on an existing instance, but with a new list of members.

This method will not assign any new owners, so it will not require a state transfer. The only exception is if a segment doesn't have any owners in the new members list - but there isn't anyone to transfer that segment from, so that won't require a state transfer either.

Specified by:

updateMembers in interface ConsistentHashFactory<ReplicatedConsistentHash>

Parameters:

baseCH - An existing consistent hash instance, should not be null

newMembers - A list of addresses representing the new cache members.

actualCapacityFactors - The capacity factor of each member. Determines the relative capacity of each node compared to the others. The implementation may ignore this parameter. If null, all the members are assumed to have a capacity factor of 1.

Returns:

A new ConsistentHash instance, or baseCH if the existing instance does not need any changes.

rebalance

public ReplicatedConsistentHash rebalance(ReplicatedConsistentHash baseCH)

Description copied from interface: ConsistentHashFactory

Create a new consistent hash instance, based on an existing instance, but "balanced" according to the implementation's rules.

It must be possible to switch from the "intermediary" consistent hash that includes the old owners to the new consistent hash without any state transfer.

rebalance(rebalance(ch)) must be equivalent to rebalance(ch).

Specified by:

rebalance in interface ConsistentHashFactory<ReplicatedConsistentHash>

Parameters:

baseCH - An existing consistent hash instance, should not be null

Returns:

A new ConsistentHash instance, or baseCH if the existing instance does not need any changes.

union

public ReplicatedConsistentHash union(ReplicatedConsistentHash ch1,
                             ReplicatedConsistentHash ch2)

Description copied from interface: ConsistentHashFactory

Creates a union of two compatible ConsistentHashes (use the same hashing function and have the same configuration parameters).

Specified by:

union in interface ConsistentHashFactory<ReplicatedConsistentHash>