org.apache.hadoop.hbase.client.replication

Class ReplicationAdmin

java.lang.Object

org.apache.hadoop.hbase.client.replication.ReplicationAdmin

All Implemented Interfaces:

Closeable, AutoCloseable

@InterfaceAudience.Public
@InterfaceStability.Evolving
public class ReplicationAdmin
extends Object
implements Closeable

This class provides the administrative interface to HBase cluster replication. In order to use it, the cluster and the client using ReplicationAdmin must be configured with hbase.replication set to true.

Adding a new peer results in creating new outbound connections from every region server to a subset of region servers on the slave cluster. Each new stream of replication will start replicating from the beginning of the current HLog, meaning that edits from that past will be replicated.

Removing a peer is a destructive and irreversible operation that stops all the replication streams for the given cluster and deletes the metadata used to keep track of the replication state.

To see which commands are available in the shell, type replication.

Field Summary

Fields

Modifier and Type	Field and Description
static String	CFNAME
static String	REPLICATIONGLOBAL
static String	REPLICATIONTYPE
static String	TNAME

Constructor Summary

Constructors

Constructor and Description
ReplicationAdmin(org.apache.hadoop.conf.Configuration conf) Constructor that creates a connection to the local ZooKeeper ensemble.

Method Summary

Methods

Modifier and Type	Method and Description
void	addPeer(String id, String clusterKey) Add a new peer cluster to replicate to.
void	close()
void	disablePeer(String id) Stop the replication stream to the specified peer.
void	enablePeer(String id) Restart the replication stream to the specified peer.
int	getPeersCount() Get the number of slave clusters the local cluster has.
boolean	getPeerState(String id) Get the state of the specified peer cluster
Map<String,String>	listPeers() Map of this cluster's peers for display.
List<HashMap<String,String>>	listReplicated() Find all column families that are replicated from this cluster
void	removePeer(String id) Removes a peer cluster and stops the replication to it.

Methods inherited from class java.lang.Object

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

Field Detail

TNAME

public static final String TNAME

See Also:

Constant Field Values

CFNAME

public static final String CFNAME

See Also:

Constant Field Values

REPLICATIONTYPE

public static final String REPLICATIONTYPE

See Also:

Constant Field Values

REPLICATIONGLOBAL

public static final String REPLICATIONGLOBAL

Constructor Detail

ReplicationAdmin

public ReplicationAdmin(org.apache.hadoop.conf.Configuration conf)
                 throws IOException

Constructor that creates a connection to the local ZooKeeper ensemble.

Parameters:

conf - Configuration to use

Throws:

IOException - if an internal replication error occurs

RuntimeException - if replication isn't enabled.

Method Detail

addPeer

public void addPeer(String id,
           String clusterKey)
             throws ReplicationException

Add a new peer cluster to replicate to.

Parameters:

id - a short that identifies the cluster

clusterKey - the concatenation of the slave cluster's hbase.zookeeper.quorum:hbase.zookeeper.property.clientPort:zookeeper.znode.parent

Throws:

IllegalStateException - if there's already one slave since multi-slave isn't supported yet.

ReplicationException

removePeer

public void removePeer(String id)
                throws ReplicationException

Removes a peer cluster and stops the replication to it.

Parameters:

id - a short that identifies the cluster

Throws:

ReplicationException

enablePeer

public void enablePeer(String id)
                throws ReplicationException

Restart the replication stream to the specified peer.

Parameters:

id - a short that identifies the cluster

Throws:

ReplicationException

disablePeer

public void disablePeer(String id)
                 throws ReplicationException

Stop the replication stream to the specified peer.

Parameters:

id - a short that identifies the cluster

Throws:

ReplicationException

getPeersCount

public int getPeersCount()

Get the number of slave clusters the local cluster has.

Returns:

number of slave clusters

listPeers

public Map<String,String> listPeers()

Map of this cluster's peers for display.

Returns:

A map of peer ids to peer cluster keys

getPeerState

public boolean getPeerState(String id)
                     throws ReplicationException

Get the state of the specified peer cluster

Parameters:

id - String format of the Short that identifies the peer, an IllegalArgumentException is thrown if it doesn't exist

Returns:

true if replication is enabled to that peer, false if it isn't

Throws:

ReplicationException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

listReplicated

public List<HashMap<String,String>> listReplicated()
                                            throws IOException

Find all column families that are replicated from this cluster

Returns:

the full list of the replicated column families of this cluster as: tableName, family name, replicationType Currently replicationType is Global. In the future, more replication types may be extended here. For example 1) the replication may only apply to selected peers instead of all peers 2) the replicationType may indicate the host Cluster servers as Slave for the table:columnFam.

Throws:

IOException