org.apache.hadoop.hbase.zookeeper

Class MetaTableLocator

java.lang.Object

org.apache.hadoop.hbase.zookeeper.MetaTableLocator

@InterfaceAudience.Private
public class MetaTableLocator
extends Object

Utility class to perform operation (get/wait for/verify/set/delete) on znode in ZooKeeper which keeps hbase:meta region server location. Stateless class with a bunch of static methods. Doesn't manage resources passed in (e.g. Connection, ZKWatcher etc). Meta region location is set by RegionServerServices. This class doesn't use ZK watchers, rather accesses ZK directly. This class it stateless. The only reason it's not made a non-instantiable util class with a collection of static methods is that it'd be rather hard to mock properly in tests. TODO: rewrite using RPC calls to master to find out about hbase:meta.

Constructor Summary

Constructors

Constructor and Description
MetaTableLocator()

Method Summary

Modifier and Type	Method and Description
ServerName	blockUntilAvailable(ZKWatcher zkw, int replicaId, long timeout) Wait until the meta region is available and is not in transition.
ServerName	blockUntilAvailable(ZKWatcher zkw, long timeout) Wait until the meta region is available and is not in transition.
List<ServerName>	blockUntilAvailable(ZKWatcher zkw, long timeout, org.apache.hadoop.conf.Configuration conf) Wait until the primary meta region is available.
void	deleteMetaLocation(ZKWatcher zookeeper) Deletes the location of hbase:meta in ZooKeeper.
void	deleteMetaLocation(ZKWatcher zookeeper, int replicaId)
ServerName	getMetaRegionLocation(ZKWatcher zkw) Gets the meta region location, if available.
ServerName	getMetaRegionLocation(ZKWatcher zkw, int replicaId) Gets the meta region location, if available.
List<RegionInfo>	getMetaRegions(ZKWatcher zkw) Gets the meta regions for the given path with the default replica ID.
List<RegionInfo>	getMetaRegions(ZKWatcher zkw, int replicaId) Gets the meta regions for the given path and replica ID.
List<Pair<RegionInfo,ServerName>>	getMetaRegionsAndLocations(ZKWatcher zkw)
List<Pair<RegionInfo,ServerName>>	getMetaRegionsAndLocations(ZKWatcher zkw, int replicaId) Gets the meta regions and their locations for the given path and replica ID.
static RegionState	getMetaRegionState(ZKWatcher zkw) Load the meta region state from the meta server ZNode.
static RegionState	getMetaRegionState(ZKWatcher zkw, int replicaId) Load the meta region state from the meta server ZNode.
boolean	isLocationAvailable(ZKWatcher zkw) Checks if the meta region location is available.
static void	setMetaLocation(ZKWatcher zookeeper, ServerName serverName, int replicaId, RegionState.State state) Sets the location of hbase:meta in ZooKeeper to the specified server address.
static void	setMetaLocation(ZKWatcher zookeeper, ServerName serverName, RegionState.State state) Sets the location of hbase:meta in ZooKeeper to the specified server address.
void	stop() Stop working.
boolean	verifyMetaRegionLocation(ClusterConnection hConnection, ZKWatcher zkw, long timeout) Verify hbase:meta is deployed and accessible.
boolean	verifyMetaRegionLocation(ClusterConnection connection, ZKWatcher zkw, long timeout, int replicaId) Verify hbase:meta is deployed and accessible.
void	waitMetaRegionLocation(ZKWatcher zkw) Waits indefinitely for availability of hbase:meta.
ServerName	waitMetaRegionLocation(ZKWatcher zkw, int replicaId, long timeout) Gets the meta region location, if available, and waits for up to the specified timeout if not immediately available.
ServerName	waitMetaRegionLocation(ZKWatcher zkw, 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 java.lang.Object

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

Constructor Detail

MetaTableLocator

public MetaTableLocator()

Method Detail

isLocationAvailable

public boolean isLocationAvailable(ZKWatcher zkw)

Checks if the meta region location is available.

Returns:

true if meta region location is available, false if not

getMetaRegionsAndLocations

public List<Pair<RegionInfo,ServerName>> getMetaRegionsAndLocations(ZKWatcher zkw)

Parameters:

zkw - ZooKeeper watcher to be used

Returns:

meta table regions and their locations.

getMetaRegionsAndLocations

public List<Pair<RegionInfo,ServerName>> getMetaRegionsAndLocations(ZKWatcher zkw,
                                                                    int replicaId)

Gets the meta regions and their locations for the given path and replica ID.

Parameters:

zkw - reference to the ZKWatcher which also contains configuration and operation

replicaId - the ID of the replica

Returns:

meta table regions and their locations.

getMetaRegions

public List<RegionInfo> getMetaRegions(ZKWatcher zkw)

Gets the meta regions for the given path with the default replica ID.

Parameters:

zkw - ZooKeeper watcher to be used

Returns:

List of meta regions

getMetaRegions

public List<RegionInfo> getMetaRegions(ZKWatcher zkw,
                                       int replicaId)

Gets the meta regions for the given path and replica ID.

Parameters:

zkw - reference to the ZKWatcher which also contains configuration and operation

replicaId - the ID of the replica

Returns:

List of meta regions

getMetaRegionLocation

public ServerName getMetaRegionLocation(ZKWatcher zkw)

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

Parameters:

zkw - zookeeper connection to use

Returns:

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

getMetaRegionLocation

public ServerName getMetaRegionLocation(ZKWatcher zkw,
                                        int replicaId)

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

Parameters:

zkw - reference to the ZKWatcher which also contains configuration and operation

replicaId - the ID of the replica

Returns:

server name

waitMetaRegionLocation

public ServerName waitMetaRegionLocation(ZKWatcher zkw,
                                         long timeout)
                                  throws InterruptedException,
                                         NotAllMetaRegionsOnlineException

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:

zkw - reference to the ZKWatcher which also contains configuration and operation

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

NotAllMetaRegionsOnlineException - if a meta or root region is not online

waitMetaRegionLocation

public ServerName waitMetaRegionLocation(ZKWatcher zkw,
                                         int replicaId,
                                         long timeout)
                                  throws InterruptedException,
                                         NotAllMetaRegionsOnlineException

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:

zkw - reference to the ZKWatcher which also contains configuration and operation

replicaId - the ID of the replica

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 waiting for the socket operation fails

NotAllMetaRegionsOnlineException - if a meta or root region is not online

waitMetaRegionLocation

public void waitMetaRegionLocation(ZKWatcher zkw)
                            throws InterruptedException

Waits indefinitely for availability of hbase:meta. Used during cluster startup. Does not verify meta, just that something has been set up in zk.

Throws:

InterruptedException - if interrupted while waiting

See Also:

waitMetaRegionLocation(ZKWatcher, long)

verifyMetaRegionLocation

public boolean verifyMetaRegionLocation(ClusterConnection hConnection,
                                        ZKWatcher zkw,
                                        long timeout)
                                 throws InterruptedException,
                                        IOException

Verify hbase:meta is deployed and accessible.

Parameters:

hConnection - the connection to use

zkw - reference to the ZKWatcher which also contains configuration and operation

timeout - How long to wait on zk for meta address (passed through to the internal call to getMetaServerConnection(org.apache.hadoop.hbase.client.ClusterConnection, org.apache.hadoop.hbase.zookeeper.ZKWatcher, long, int).

Returns:

True if the hbase:meta location is healthy.

Throws:

IOException - if the number of retries for getting the connection is exceeded

InterruptedException - if waiting for the socket operation fails

verifyMetaRegionLocation

public boolean verifyMetaRegionLocation(ClusterConnection connection,
                                        ZKWatcher zkw,
                                        long timeout,
                                        int replicaId)
                                 throws InterruptedException,
                                        IOException

Verify hbase:meta is deployed and accessible.

Parameters:

connection - the connection to use

zkw - reference to the ZKWatcher which also contains configuration and operation

timeout - How long to wait on zk for meta address (passed through to

replicaId - the ID of the replica

Returns:

True if the hbase:meta location is healthy.

Throws:

InterruptedException - if waiting for the socket operation fails

IOException - if the number of retries for getting the connection is exceeded

setMetaLocation

public static void setMetaLocation(ZKWatcher zookeeper,
                                   ServerName serverName,
                                   RegionState.State state)
                            throws org.apache.zookeeper.KeeperException

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

Parameters:

zookeeper - zookeeper reference

serverName - The server hosting hbase:meta

state - The region transition state

Throws:

org.apache.zookeeper.KeeperException - unexpected zookeeper exception

setMetaLocation

public static void setMetaLocation(ZKWatcher zookeeper,
                                   ServerName serverName,
                                   int replicaId,
                                   RegionState.State state)
                            throws org.apache.zookeeper.KeeperException

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

Parameters:

zookeeper - reference to the ZKWatcher which also contains configuration and operation

serverName - the name of the server

replicaId - the ID of the replica

state - the state of the region

Throws:

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

getMetaRegionState

public static RegionState getMetaRegionState(ZKWatcher zkw)
                                      throws org.apache.zookeeper.KeeperException

Load the meta region state from the meta server ZNode.

Throws:

org.apache.zookeeper.KeeperException

getMetaRegionState

public static RegionState getMetaRegionState(ZKWatcher zkw,
                                             int replicaId)
                                      throws org.apache.zookeeper.KeeperException

Load the meta region state from the meta server ZNode.

Parameters:

zkw - reference to the ZKWatcher which also contains configuration and operation

replicaId - the ID of the replica

Returns:

regionstate

Throws:

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

deleteMetaLocation

public void deleteMetaLocation(ZKWatcher 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

deleteMetaLocation

public void deleteMetaLocation(ZKWatcher zookeeper,
                               int replicaId)
                        throws org.apache.zookeeper.KeeperException

Throws:

org.apache.zookeeper.KeeperException

blockUntilAvailable

public List<ServerName> blockUntilAvailable(ZKWatcher zkw,
                                            long timeout,
                                            org.apache.hadoop.conf.Configuration conf)
                                     throws InterruptedException

Wait until the primary meta region is available. Get the secondary locations as well but don't block for those.

Parameters:

zkw - reference to the ZKWatcher which also contains configuration and operation

timeout - maximum time to wait in millis

conf - the Configuration to use

Returns:

ServerName or null if we timed out.

Throws:

InterruptedException - if waiting for the socket operation fails

blockUntilAvailable

public ServerName blockUntilAvailable(ZKWatcher zkw,
                                      long timeout)
                               throws InterruptedException

Wait until the meta region is available and is not in transition.

Parameters:

zkw - zookeeper connection to use

timeout - maximum time to wait, in millis

Returns:

ServerName or null if we timed out.

Throws:

InterruptedException - if waiting for the socket operation fails

blockUntilAvailable

public ServerName blockUntilAvailable(ZKWatcher zkw,
                                      int replicaId,
                                      long timeout)
                               throws InterruptedException

Wait until the meta region is available and is not in transition.

Parameters:

zkw - reference to the ZKWatcher which also contains configuration and constants

replicaId - the ID of the replica

timeout - maximum time to wait in millis

Returns:

ServerName or null if we timed out.

Throws:

InterruptedException - if waiting for the socket operation fails

stop

public void stop()

Stop working. Interrupts any ongoing waits.