Package org.apache.hadoop.hbase.zookeeper

Class ZKClusterId

java.lang.Object

org.apache.hadoop.hbase.zookeeper.ZKClusterId

@Private
public class ZKClusterId
extends Object

Publishes and synchronizes a unique identifier specific to a given HBase cluster. The stored identifier is read from the file system by the active master on startup, and is subsequently available to all watchers (including clients).

Field Summary

Fields

Modifier and Type	Field	Description
private final Abortable	abortable
private String	id
private final ZKWatcher	watcher

Constructor Summary

Constructors

Constructor	Description
ZKClusterId(ZKWatcher watcher, Abortable abortable)

Method Summary

Modifier and Type	Method	Description
String	getId()
static UUID	getUUIDForCluster(ZKWatcher zkw)	Get the UUID for the provided ZK watcher.
boolean	hasId()
static String	readClusterIdZNode(ZKWatcher watcher)
static void	setClusterId(ZKWatcher watcher, ClusterId id)

Methods inherited from class java.lang.Object

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

Field Details

watcher

private final ZKWatcher watcher

abortable

private final Abortable abortable

id

private String id

Constructor Details

ZKClusterId

public ZKClusterId(ZKWatcher watcher,
 Abortable abortable)

Method Details

hasId

public boolean hasId()

getId

public String getId()

readClusterIdZNode

public static String readClusterIdZNode(ZKWatcher watcher)
                                 throws org.apache.zookeeper.KeeperException

Throws:

org.apache.zookeeper.KeeperException

setClusterId

public static void setClusterId(ZKWatcher watcher,
 ClusterId id)
                         throws org.apache.zookeeper.KeeperException

Throws:

org.apache.zookeeper.KeeperException

getUUIDForCluster

public static UUID getUUIDForCluster(ZKWatcher zkw)
                              throws org.apache.zookeeper.KeeperException

Get the UUID for the provided ZK watcher. Doesn't handle any ZK exceptions

Parameters:

zkw - watcher connected to an ensemble

Returns:

the UUID read from zookeeper

Throws:

org.apache.zookeeper.KeeperException - if a ZooKeeper operation fails