org.lable.oss.uniqueid.zookeeper

Class SynchronizedUniqueIDGenerator

java.lang.Object

org.lable.oss.uniqueid.BaseUniqueIDGenerator

org.lable.oss.uniqueid.zookeeper.SynchronizedUniqueIDGenerator

All Implemented Interfaces:

IDGenerator

public class SynchronizedUniqueIDGenerator
extends BaseUniqueIDGenerator

A BaseUniqueIDGenerator that coordinates the generator ID used by other processes using this class via the same ZooKeeper quorum by attempting to claim an available ID for itself.

Although claims on a generator ID will be automatically relinquished after the connection to the ZooKeeper quorum is lost, instances of this class should be explicitly closed after use, if you do not expect to generate anymore IDs at that time.

Because claimed generator IDs are automatically returned to the pool after a set time (ExpiringResourceClaim.DEFAULT_TIMEOUT), there is no guarantee that IDs generated have the same generator ID.

Nested Class Summary

Nested classes/interfaces inherited from class org.lable.oss.uniqueid.BaseUniqueIDGenerator

BaseUniqueIDGenerator.Blueprint

Field Summary

Fields inherited from class org.lable.oss.uniqueid.BaseUniqueIDGenerator

clusterId, generatorId, MAX_CLUSTER_ID, MAX_GENERATOR_ID, MAX_SEQUENCE_COUNTER, MAX_TIMESTAMP

Method Summary

Modifier and Type	Method and Description
byte[]	generate()
static SynchronizedUniqueIDGenerator	generatorFor(String zookeeperQuorum, String znode) Get the synchronized ID generator instance.
void	relinquishGeneratorIDClaim() Return the claimed generator ID to the pool.

Methods inherited from class org.lable.oss.uniqueid.BaseUniqueIDGenerator

assertParameterWithinBounds, batch, parse

Methods inherited from class java.lang.Object

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

Method Detail

generatorFor

public static SynchronizedUniqueIDGenerator generatorFor(String zookeeperQuorum,
                                                         String znode)
                                                  throws IOException

Get the synchronized ID generator instance.

Parameters:

zookeeperQuorum - Addresses of the ZooKeeper quorum to connect to.

znode - Base-path of the resource pool in ZooKeeper.

Returns:

An instance of this class.

Throws:

IOException - Thrown when something went wrong trying to find the cluster ID or trying to claim a generator ID.

generate

public byte[] generate()
                throws GeneratorException

Specified by:

generate in interface IDGenerator

Overrides:

generate in class BaseUniqueIDGenerator

Throws:

GeneratorException

relinquishGeneratorIDClaim

public void relinquishGeneratorIDClaim()

Return the claimed generator ID to the pool. Call this when you are done generating IDs. If you don't the claim will expire automatically, but this takes a while.