com.sleepycat.je.rep.arbitration

Class Arbiter

java.lang.Object

com.sleepycat.je.rep.arbitration.Arbiter

public class Arbiter
extends Object

The locus for management of this node's active arbitration state, and of the mechanisms available to this node for doing arbitration.

A node is in active arbitration state if

• is the master
• is lacking the required durability quorum
• is maintaining its authoritative master status and its ability to commit writes through the good graces of an ArbiterProvider.

The Arbiter detects which arbitration options are available in the JE HA group.

Constructor Summary

Constructors

Constructor and Description
Arbiter(RepImpl repImpl) Examine environment configuration and rep group membership to figure out which arbitration options are in operation for this HA group.

Method Summary

Modifier and Type	Method and Description
boolean	activateArbitration() The replication node knows that it has lost its durability quorum, and wants to try to enter active arbitration mode.
boolean	activationPossible() Return true if it's possible that this node can switch into active arbitration.
void	endArbitration() The node has determined that it need not be in active arbitration.
int	getAckCount(Durability.ReplicaAckPolicy ackPolicy) Return the arbitration-influenced durability quorum size.
int	getElectionQuorumSize(QuorumPolicy quorumPolicy) Return the arbitration-influenced election quorum size.
boolean	isActive() Return true if this node is in active arbitration.
boolean	isApplicable(Durability.ReplicaAckPolicy ackPolicy) Return true if this node is in active arbitration, and if arbitration should take precedence over the durability quorum policy.
boolean	isApplicable(QuorumPolicy quorumPolicy) Return true if this node is in active arbitration, and if arbitration should take precedence over the election quorum policy.
void	processConfigChange(ReplicationMutableConfig newConfig) The replication configuration was changed.

Methods inherited from class java.lang.Object

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

Constructor Detail

Arbiter

public Arbiter(RepImpl repImpl)

Examine environment configuration and rep group membership to figure out which arbitration options are in operation for this HA group.

Method Detail

activateArbitration

public boolean activateArbitration()

The replication node knows that it has lost its durability quorum, and wants to try to enter active arbitration mode.

Returns:

true if the node successfully transitions to active arbitration, or was already in active arbitration.

endArbitration

public void endArbitration()

The node has determined that it need not be in active arbitration. End the active arbitration state. If the node was not in active arbitration, do nothing.

activationPossible

public boolean activationPossible()

Return true if it's possible that this node can switch into active arbitration. The criteria for activation depend on the type of arbitration enabled for this node.

For example, if designated primary arbitration is used, then it's only possible to move into active arbitration if the Designated Primary configuration parameter is set for this node. If LWT Node arbitration is used, then this node must have a valid connection to the arbiter node.

isApplicable

public boolean isApplicable(QuorumPolicy quorumPolicy)

Return true if this node is in active arbitration, and if arbitration should take precedence over the election quorum policy.

isApplicable

public boolean isApplicable(Durability.ReplicaAckPolicy ackPolicy)

Return true if this node is in active arbitration, and if arbitration should take precedence over the durability quorum policy.

getElectionQuorumSize

public int getElectionQuorumSize(QuorumPolicy quorumPolicy)

Return the arbitration-influenced election quorum size. Arbitration may reduce the value that would usually be indicated by the quorum policy.

getAckCount

public int getAckCount(Durability.ReplicaAckPolicy ackPolicy)

Return the arbitration-influenced durability quorum size. Arbitration may reduce the value that would usually be indicated by the ack policy.

processConfigChange

public void processConfigChange(ReplicationMutableConfig newConfig)

The replication configuration was changed. Check the new configuration to see it impacts active arbitration state or makes more arbitration mechanisms available. For example, if we are in active arbitration using designated primary arbitration, a change to the node's designated primary configuration parameter may affect whether this node can stay in active arbitration.

isActive

public boolean isActive()

Return true if this node is in active arbitration.