com.sleepycat.je.rep.arbiter

Class Arbiter

java.lang.Object

com.sleepycat.je.rep.arbiter.Arbiter

public class Arbiter
extends java.lang.Object

Provides a mechanism to allow write availability for the Replication group even when the number of replication nodes is less than majority. The main use of an Arbiter is when the replication group consists of two nodes. The addition of an Arbiter to the replication group allows for one node to fail and provide write availability with ACK durability of SIMPLE_MAJORITY. The Arbiter acknowledges the transaction, but does not retain a copy of the data. The Arbiter persists a small amount of state to insure that only the Replication nodes that contain the Arbiter acknowledged transactions may become a Master.

The Arbiter node participates in elections and may acknowledge transaction commits.

The Arbiter state is as follows: UNKNOWN [ UNKNOWN | REPLICA]+ DETACHED

Constructor Summary

Constructors

Constructor and Description
Arbiter(ArbiterConfig arbiterConfig) An Arbiter used in elections and transaction acknowledgments.

Method Summary

Modifier and Type	Method and Description
ArbiterMutableConfig	getArbiterMutableConfig() Returns the Arbiter mutable attributes.
ReplicatedEnvironment.State	getState() Gets the Arbiter state.
ArbiterStats	getStats(StatsConfig config) Gets the Arbiter statistics.
void	setArbiterMutableConfig(ArbiterMutableConfig config) Sets the Arbiter mutable attributes.
void	shutdown() Shutdown the Arbiter.

Methods inherited from class java.lang.Object

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

Constructor Detail

Arbiter

public Arbiter(ArbiterConfig arbiterConfig)
        throws EnvironmentNotFoundException,
               EnvironmentLockedException,
               DatabaseException,
               java.lang.IllegalArgumentException

An Arbiter used in elections and transaction acknowledgments. This method returns when a connection to the current master replication node is made. The Arbiter.shutdown() method is used to shutdown the threads that run as part of the Arbiter.

Parameters:

arbiterConfig - Configuration parameters for the Arbiter.

Throws:

EnvironmentNotFoundException - if the environment does not exist

EnvironmentLockedException - when an environment cannot be opened because another Arbiter has the environment open.

DatabaseException - problem establishing connection to the master.

java.lang.IllegalArgumentException - if an invalid parameter is specified, for example, an invalid ArbiterConfig parameter.

Method Detail

getArbiterMutableConfig

public ArbiterMutableConfig getArbiterMutableConfig()

Returns the Arbiter mutable attributes.

Returns:

Arbiter attributes.

setArbiterMutableConfig

public void setArbiterMutableConfig(ArbiterMutableConfig config)
                             throws DatabaseException

Sets the Arbiter mutable attributes.

Parameters:

config - Arbiter attributes.

Throws:

DatabaseException

getState

public ReplicatedEnvironment.State getState()

Gets the Arbiter state.

getStats

public ArbiterStats getStats(StatsConfig config)
                      throws DatabaseException

Gets the Arbiter statistics.

Parameters:

config - The general statistics attributes. If null, default attributes are used.

Returns:

Arbiter statistics.

Throws:

DatabaseException

shutdown

public void shutdown()
              throws DatabaseException

Shutdown the Arbiter. Threads are stopped and resources are released.

Throws:

DatabaseException