com.sleepycat.je.rep

Enum QuorumPolicy

java.lang.Object

java.lang.Enum<QuorumPolicy>

com.sleepycat.je.rep.QuorumPolicy

All Implemented Interfaces:

Serializable, Comparable<QuorumPolicy>

public enum QuorumPolicy
extends Enum<QuorumPolicy>

The quorum policy determine the number of nodes that must participate to pick the winner of an election, and therefore the master of the group. The default quorum policy during the lifetime of the group is QuorumPolicy.SIMPLE_MAJORITY. The only time that the application needs to specify a specific quorum policy is at node startup time, by passing one to the ReplicatedEnvironment constructor.

Note that NodeType.SECONDARY nodes are not counted as part of master election quorums.

Enum Constant Summary

Enum Constants

Enum Constant and Description
ALL All participants are required to vote.
SIMPLE_MAJORITY A simple majority of participants is required to vote.

Method Summary

Modifier and Type	Method and Description
int	quorumSize(int groupSize) Returns the minimum number of nodes to needed meet the quorum policy.
static QuorumPolicy	valueOf(String name) Returns the enum constant of this type with the specified name.
static QuorumPolicy[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

ALL

public static final QuorumPolicy ALL

All participants are required to vote.

SIMPLE_MAJORITY

public static final QuorumPolicy SIMPLE_MAJORITY

A simple majority of participants is required to vote.

Method Detail

values

public static QuorumPolicy[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (QuorumPolicy c : QuorumPolicy.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static QuorumPolicy valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

quorumSize

public int quorumSize(int groupSize)

Returns the minimum number of nodes to needed meet the quorum policy.

Parameters:

groupSize - the number of election participants in the replication group

Returns:

the number of nodes that are needed for a quorum for a group with groupSize number of election participants