org.wildfly.clustering.singleton.election

Class SimpleSingletonElectionPolicy

java.lang.Object

org.wildfly.clustering.singleton.election.SimpleSingletonElectionPolicy

All Implemented Interfaces:

SingletonElectionPolicy

public class SimpleSingletonElectionPolicy
extends Object
implements SingletonElectionPolicy

A simple concrete policy service that decides which node in the cluster should be the primary node to run certain HASingleton service based on attribute "Position". The value will be divided by partition size and only remainder will be used. Let's say partition size is n: 0 means the first oldest node. 1 means the 2nd oldest node. ... n-1 means the nth oldest node. -1 means the youngest node. -2 means the 2nd youngest node. ... -n means the nth youngest node. E.g. the following attribute says the singleton will be running on the 3rd oldest node of the current partition: 2 If no election policy is defined, the oldest node in the cluster runs the singleton. This behavior can be achieved with this policy when "position" is set to 0.

Author:

Alex Fu, Galder Zamarreno, Paul Ferraro

Constructor Summary

Constructors

Constructor and Description
SimpleSingletonElectionPolicy()
SimpleSingletonElectionPolicy(int position)

Method Summary

Modifier and Type	Method and Description
Node	elect(List<Node> candidates) Elect a single node from the specified list of candidate nodes.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleSingletonElectionPolicy

public SimpleSingletonElectionPolicy()

SimpleSingletonElectionPolicy

public SimpleSingletonElectionPolicy(int position)

Method Detail

elect

public Node elect(List<Node> candidates)

Description copied from interface: SingletonElectionPolicy

Elect a single node from the specified list of candidate nodes.

Specified by:

elect in interface SingletonElectionPolicy

Parameters:

candidates - a list of candidate nodes.

Returns:

the elected node