org.apache.hadoop.hbase.zookeeper
Class RootRegionTracker

java.lang.Object
  org.apache.hadoop.hbase.zookeeper.ZooKeeperListener
      org.apache.hadoop.hbase.zookeeper.ZooKeeperNodeTracker
          org.apache.hadoop.hbase.zookeeper.RootRegionTracker

@InterfaceAudience.Private
public class RootRegionTracker
extends ZooKeeperNodeTracker

Tracks the root region server location node in zookeeper. Root region location is set by RegionServerServices. This class has a watcher on the root location and notices changes.

Field Summary

Fields inherited from class org.apache.hadoop.hbase.zookeeper.ZooKeeperNodeTracker

abortable, node

Fields inherited from class org.apache.hadoop.hbase.zookeeper.ZooKeeperListener

watcher

Constructor Summary

RootRegionTracker(ZooKeeperWatcher watcher, Abortable abortable)
Creates a root region location tracker.

Method Summary

static ServerName	blockUntilAvailable(ZooKeeperWatcher zkw, long timeout) Wait until the root region is available.
static void	deleteRootLocation(ZooKeeperWatcher zookeeper) Deletes the location of -ROOT- in ZooKeeper.
ServerName	getRootRegionLocation() Gets the root region location, if available.
static ServerName	getRootRegionLocation(ZooKeeperWatcher zkw) Gets the root region location, if available.
boolean	isLocationAvailable() Checks if the root region location is available.
static void	setRootLocation(ZooKeeperWatcher zookeeper, ServerName location) Sets the location of -ROOT- in ZooKeeper to the specified server address.
ServerName	waitRootRegionLocation(long timeout) Gets the root region location, if available, and waits for up to the specified timeout if not immediately available.

Methods inherited from class org.apache.hadoop.hbase.zookeeper.ZooKeeperNodeTracker

blockUntilAvailable, blockUntilAvailable, checkIfBaseNodeAvailable, getData, getNode, nodeCreated, nodeDataChanged, nodeDeleted, start, stop

Methods inherited from class org.apache.hadoop.hbase.zookeeper.ZooKeeperListener

nodeChildrenChanged

Methods inherited from class java.lang.Object

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

Constructor Detail

RootRegionTracker

public RootRegionTracker(ZooKeeperWatcher watcher,
                         Abortable abortable)

Creates a root region location tracker.

After construction, use ZooKeeperNodeTracker.start() to kick off tracking.

Parameters:

watcher -

abortable -

Method Detail

isLocationAvailable

public boolean isLocationAvailable()

Checks if the root region location is available.

Returns:

true if root region location is available, false if not

getRootRegionLocation

public ServerName getRootRegionLocation()
                                 throws InterruptedException

Gets the root region location, if available. Does not block. Sets a watcher.

Returns:

server name or null if we failed to get the data.

Throws:

InterruptedException

getRootRegionLocation

public static ServerName getRootRegionLocation(ZooKeeperWatcher zkw)
                                        throws org.apache.zookeeper.KeeperException

Gets the root region location, if available. Does not block. Does not set a watcher (In this regard it differs from getRootRegionLocation().

Parameters:

zkw -

Returns:

server name or null if we failed to get the data.

Throws:

org.apache.zookeeper.KeeperException

waitRootRegionLocation

public ServerName waitRootRegionLocation(long timeout)
                                  throws InterruptedException

Gets the root region location, if available, and waits for up to the specified timeout if not immediately available. Given the zookeeper notification could be delayed, we will try to get the latest data.

Parameters:

timeout - maximum time to wait, in millis

Returns:

server name for server hosting root region formatted as per ServerName, or null if none available

Throws:

InterruptedException - if interrupted while waiting

setRootLocation

public static void setRootLocation(ZooKeeperWatcher zookeeper,
                                   ServerName location)
                            throws org.apache.zookeeper.KeeperException

Sets the location of -ROOT- in ZooKeeper to the specified server address.

Parameters:

zookeeper - zookeeper reference

location - The server hosting -ROOT-

Throws:

org.apache.zookeeper.KeeperException - unexpected zookeeper exception

deleteRootLocation

public static void deleteRootLocation(ZooKeeperWatcher zookeeper)
                               throws org.apache.zookeeper.KeeperException

Deletes the location of -ROOT- in ZooKeeper.

Parameters:

zookeeper - zookeeper reference

Throws:

org.apache.zookeeper.KeeperException - unexpected zookeeper exception

blockUntilAvailable

public static ServerName blockUntilAvailable(ZooKeeperWatcher zkw,
                                             long timeout)
                                      throws InterruptedException

Wait until the root region is available.

Parameters:

zkw -

timeout -

Returns:

ServerName or null if we timed out.

Throws:

InterruptedException