Package org.apache.pekko.routing

Class ConsistentHash<T>

java.lang.Object

org.apache.pekko.routing.ConsistentHash<T>

public class ConsistentHash<T>
extends Object

Consistent Hashing node ring implementation.

A good explanation of Consistent Hashing: https://tom-e-white.com/2007/11/consistent-hashing.html

Note that toString of the ring nodes are used for the node hash, i.e. make sure it is different for different nodes.

Constructor Summary

Constructors

Constructor	Description
ConsistentHash()

Method Summary

Modifier and Type	Method	Description
ConsistentHash<T>	$colon$minus(T node)	Removes a node from the node ring.
ConsistentHash<T>	$colon$plus(T node)	Adds a node to the node ring.
ConsistentHash<T>	add(T node)	Java API: Adds a node to the node ring.
static <T> ConsistentHash<T>	apply(scala.collection.Iterable<T> nodes, int virtualNodesFactor, scala.reflect.ClassTag<T> evidence$2)
static <T> ConsistentHash<T>	create(Iterable<T> nodes, int virtualNodesFactor)	Java API: Factory method to create a ConsistentHash
boolean	isEmpty()	Is the node ring empty, i.e.
T	nodeFor(byte[] key)	Get the node responsible for the data key.
T	nodeFor(String key)	Get the node responsible for the data key.
ConsistentHash<T>	remove(T node)	Java API: Removes a node from the node ring.
int	virtualNodesFactor()

Methods inherited from class java.lang.Object

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

Constructor Details

ConsistentHash

public ConsistentHash()

Method Details

apply

public static <T> ConsistentHash<T> apply(scala.collection.Iterable<T> nodes,
 int virtualNodesFactor,
 scala.reflect.ClassTag<T> evidence$2)

create

public static <T> ConsistentHash<T> create(Iterable<T> nodes,
 int virtualNodesFactor)

Java API: Factory method to create a ConsistentHash

virtualNodesFactor

public int virtualNodesFactor()

$colon$plus

public ConsistentHash<T> $colon$plus(T node)

Adds a node to the node ring. Note that the instance is immutable and this operation returns a new instance.

add

public ConsistentHash<T> add(T node)

Java API: Adds a node to the node ring. Note that the instance is immutable and this operation returns a new instance.

$colon$minus

public ConsistentHash<T> $colon$minus(T node)

Removes a node from the node ring. Note that the instance is immutable and this operation returns a new instance.

remove

public ConsistentHash<T> remove(T node)

Java API: Removes a node from the node ring. Note that the instance is immutable and this operation returns a new instance.

nodeFor

public T nodeFor(byte[] key)

Get the node responsible for the data key. Can only be used if nodes exists in the node ring, otherwise throws IllegalStateException

nodeFor

public T nodeFor(String key)

Get the node responsible for the data key. Can only be used if nodes exists in the node ring, otherwise throws IllegalStateException

isEmpty

public boolean isEmpty()

Is the node ring empty, i.e. no nodes added or all removed.