org.apache.hadoop.hbase.zookeeper
Class MetaRegionTracker

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

@InterfaceAudience.Private
public class MetaRegionTracker
extends ZooKeeperNodeTracker

Tracks the meta region server location node in zookeeper. Meta region location is set by RegionServerServices. This class has a watcher on the meta 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

MetaRegionTracker(ZooKeeperWatcher watcher, Abortable abortable)
Creates a meta region location tracker.

Method Summary

static ServerName	blockUntilAvailable(ZooKeeperWatcher zkw, long timeout) Wait until the meta region is available.
static void	deleteMetaLocation(ZooKeeperWatcher zookeeper) Deletes the location of hbase:meta in ZooKeeper.
ServerName	getMetaRegionLocation() Gets the meta region location, if available.
static ServerName	getMetaRegionLocation(ZooKeeperWatcher zkw) Gets the meta region location, if available.
RegionState	getMetaRegionState() Get meta region state
boolean	isLocationAvailable() Checks if the meta region location is available.
static void	setMetaLocation(ZooKeeperWatcher zookeeper, ServerName location, RegionState.State regionState) Sets the location of hbase:meta in ZooKeeper to the specified server address.
ServerName	waitMetaRegionLocation(long timeout) Gets the meta 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

getWatcher, nodeChildrenChanged

Methods inherited from class java.lang.Object

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

Constructor Detail

MetaRegionTracker

public MetaRegionTracker(ZooKeeperWatcher watcher,
                         Abortable abortable)

Creates a meta region location tracker.

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

Parameters:

watcher -

abortable -

Method Detail

isLocationAvailable

public boolean isLocationAvailable()

Checks if the meta region location is available.

Returns:

true if meta region location is available, false if not

getMetaRegionLocation

public ServerName getMetaRegionLocation()

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

Returns:

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

Throws:

InterruptedException

getMetaRegionLocation

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

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

Parameters:

zkw -

Returns:

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

Throws:

org.apache.zookeeper.KeeperException

waitMetaRegionLocation

public ServerName waitMetaRegionLocation(long timeout)
                                  throws InterruptedException

Gets the meta 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 meta region formatted as per ServerName, or null if none available

Throws:

InterruptedException - if interrupted while waiting

setMetaLocation

public static void setMetaLocation(ZooKeeperWatcher zookeeper,
                                   ServerName location,
                                   RegionState.State regionState)
                            throws org.apache.zookeeper.KeeperException

Sets the location of hbase:meta in ZooKeeper to the specified server address.

Parameters:

zookeeper - zookeeper reference

location - The server hosting hbase:meta

Throws:

org.apache.zookeeper.KeeperException - unexpected zookeeper exception

deleteMetaLocation

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

Deletes the location of hbase:meta 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 meta region is available.

Parameters:

zkw -

timeout -

Returns:

ServerName or null if we timed out.

Throws:

InterruptedException

getMetaRegionState

public RegionState getMetaRegionState()

Get meta region state

Returns:

RegionState