com.hp.util.dcord.election

Interface ElectionStrategy

public interface ElectionStrategy

Provides election strategy

Author:

Vamsi Krishna Devaki, Nachiket Abhyankar, Fabiel Zuniga

Method Summary

Methods

Modifier and Type	Method and Description
Node	elect(Set<Node> candidates, Node suggested, Set<Node> active, Set<Node> configured) Elects a leader from the set of candidates.

Method Detail

elect

Node elect(Set<Node> candidates,
         Node suggested,
         Set<Node> active,
         Set<Node> configured)

Elects a leader from the set of candidates. Return null if the cluster should remain without a leader. For example, in the event of a network partition the sub-cluster with quorum could elect a leader while any sub-cluster with no quorum could remain without a leader. Or a leader could be elected on each sub-cluster. It is up to the strategy.

Parameters:

candidates - potential leaders in the current cluster

suggested - suggested leader, null if no suggestion. The suggested leader is part of the candidates, and it normally represents the current leader. A suggested node is used when the election is run because a node left the cluster (Election must be run again because strategies could verify quorum).

active - the nodes currently active (Reachable nodes)

configured - the nodes that were used to configure the cluster

Returns:

the leader, null if the cluster should remain without a leader