com.bigdata.quorum

Enum QuorumStateChangeEventEnum

java.lang.Object

java.lang.Enum<QuorumStateChangeEventEnum>

com.bigdata.quorum.QuorumStateChangeEventEnum

All Implemented Interfaces:

Serializable, Comparable<QuorumStateChangeEventEnum>

public enum QuorumStateChangeEventEnum
extends Enum<QuorumStateChangeEventEnum>

Enumeration of event types for the events described by the QuorumStateChangeListener interface.

Author:

Bryan Thompson

Enum Constant Summary

Enum Constants

Enum Constant and Description
CONSENSUS Event generated when a consensus has been achieved among (k+1)/2 services concerning a shared lastCommitTime (really, this is not a consensus but a simple majority).
LOST_CONSENSUS Event generated when the consensus is lost.
MEMBER_ADD This service was added as a quorum member.
MEMBER_REMOVE This service was removed as a quorum member.
PIPELINE_ADD This service was added as a pipeline member.
PIPELINE_CHANGE Event generated when the downstream service in the write pipeline has changed.
PIPELINE_ELECTED_LEADER Event generated when a service already in the pipeline becomes the first service in the write pipeline because all previous services in the pipeline order have been removed from the pipeline.
PIPELINE_REMOVE This service was removed as a pipeline member.
PIPELINE_UPSTREAM_CHANGE Event generated when the upstream service in the write pipeline has been removed.
QUORUM_BREAK Event generated when a quorum breaks.
QUORUM_MEET Event generated when a quorum meets.
SERVICE_JOIN Event generated when this service joins the quorum.
SERVICE_LEAVE Event generated when this service leaves the quorum.

Method Summary

Methods

Modifier and Type	Method and Description
static QuorumStateChangeEventEnum	valueOf(String name) Returns the enum constant of this type with the specified name.
static QuorumStateChangeEventEnum[]	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

MEMBER_ADD

public static final QuorumStateChangeEventEnum MEMBER_ADD

This service was added as a quorum member.

See Also:

QuorumStateChangeListener.memberAdd()

MEMBER_REMOVE

public static final QuorumStateChangeEventEnum MEMBER_REMOVE

This service was removed as a quorum member.

See Also:

QuorumStateChangeListener.memberRemove()

PIPELINE_ADD

public static final QuorumStateChangeEventEnum PIPELINE_ADD

This service was added as a pipeline member.

See Also:

QuorumStateChangeListener.pipelineAdd()

PIPELINE_REMOVE

public static final QuorumStateChangeEventEnum PIPELINE_REMOVE

This service was removed as a pipeline member.

See Also:

QuorumStateChangeListener.pipelineRemove()

PIPELINE_ELECTED_LEADER

public static final QuorumStateChangeEventEnum PIPELINE_ELECTED_LEADER

Event generated when a service already in the pipeline becomes the first service in the write pipeline because all previous services in the pipeline order have been removed from the pipeline.

See Also:

QuorumStateChangeListener.pipelineElectedLeader()

PIPELINE_CHANGE

public static final QuorumStateChangeEventEnum PIPELINE_CHANGE

Event generated when the downstream service in the write pipeline has changed. Services always enter at the end of the write pipeline, but may be removed at any position in the write pipeline.

See Also:

QuorumStateChangeListener.pipelineChange(UUID, UUID)

PIPELINE_UPSTREAM_CHANGE

public static final QuorumStateChangeEventEnum PIPELINE_UPSTREAM_CHANGE

Event generated when the upstream service in the write pipeline has been removed. This hook provides an opportunity for the service to close out its connection with the old upstream service and to prepare to establish a new connection with the new downstream service.

See Also:

QuorumStateChangeListener.pipelineUpstreamChange()

CONSENSUS

public static final QuorumStateChangeEventEnum CONSENSUS

Event generated when a consensus has been achieved among (k+1)/2 services concerning a shared lastCommitTime (really, this is not a consensus but a simple majority). This message is sent to each member service regardless of whether or not they participated in the consensus.

See Also:

QuorumStateChangeListener.consensus(long)

LOST_CONSENSUS

public static final QuorumStateChangeEventEnum LOST_CONSENSUS

Event generated when the consensus is lost. Services do not withdraw their cast votes until a quorum breaks and a new consensus needs to be established.

See Also:

QuorumStateChangeListener.lostConsensus()

SERVICE_JOIN

public static final QuorumStateChangeEventEnum SERVICE_JOIN

Event generated when this service joins the quorum.

See Also:

QuorumStateChangeListener.serviceJoin()

SERVICE_LEAVE

public static final QuorumStateChangeEventEnum SERVICE_LEAVE

Event generated when this service leaves the quorum.

See Also:

QuorumStateChangeListener.serviceLeave()

QUORUM_MEET

public static final QuorumStateChangeEventEnum QUORUM_MEET

Event generated when a quorum meets.

See Also:

QuorumStateChangeListener.quorumMeet(long, UUID)

QUORUM_BREAK

public static final QuorumStateChangeEventEnum QUORUM_BREAK

Event generated when a quorum breaks.

See Also:

QuorumStateChangeListener.quorumBreak()

Method Detail

values

public static QuorumStateChangeEventEnum[] 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 (QuorumStateChangeEventEnum c : QuorumStateChangeEventEnum.values())
    System.out.println(c);

Returns:

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

valueOf

public static QuorumStateChangeEventEnum 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