org.apache.hadoop.hbase.replication
Class ReplicationPeersZKImpl

java.lang.Object
  org.apache.hadoop.hbase.replication.ReplicationStateZKBase
      org.apache.hadoop.hbase.replication.ReplicationPeersZKImpl

All Implemented Interfaces:

ReplicationPeers

public class ReplicationPeersZKImpl
extends ReplicationStateZKBase
implements ReplicationPeers

This class provides an implementation of the ReplicationPeers interface using Zookeeper. The peers znode contains a list of all peer replication clusters and the current replication state of those clusters. It has one child peer znode for each peer cluster. The peer znode is named with the cluster id provided by the user in the HBase shell. The value of the peer znode contains the peers cluster key provided by the user in the HBase Shell. The cluster key contains a list of zookeeper quorum peers, the client port for the zookeeper quorum, and the base znode for HBase. For example: /hbase/replication/peers/1 [Value: zk1.host.com,zk2.host.com,zk3.host.com:2181:/hbase] /hbase/replication/peers/2 [Value: zk5.host.com,zk6.host.com,zk7.host.com:2181:/hbase] Each of these peer znodes has a child znode that indicates whether or not replication is enabled on that peer cluster. These peer-state znodes do not have child znodes and simply contain a boolean value (i.e. ENABLED or DISABLED). This value is read/maintained by the ReplicationPeer.PeerStateTracker class. For example: /hbase/replication/peers/1/peer-state [Value: ENABLED]

Nested Class Summary

static class

ReplicationPeersZKImpl.PeerRegionServerListener Tracks changes to the list of region servers in a peer's cluster.

Field Summary

Fields inherited from class org.apache.hadoop.hbase.replication.ReplicationStateZKBase

abortable, conf, DISABLED_ZNODE_BYTES, ENABLED_ZNODE_BYTES, ourClusterKey, peerStateNodeName, peersZNode, queuesZNode, replicationZNode, zookeeper

Constructor Summary

ReplicationPeersZKImpl(ZooKeeperWatcher zk, org.apache.hadoop.conf.Configuration conf, Abortable abortable)

Method Summary

void	addPeer(String id, String clusterKey) Add a new remote slave cluster for replication.
boolean	connectToPeer(String peerId) Attempt to connect to a new remote slave cluster.
void	disablePeer(String id) Stop the replication to the specified remote slave cluster.
void	disconnectFromPeer(String peerId) Disconnect from a remote slave cluster.
void	enablePeer(String id) Restart the replication to the specified remote slave cluster.
Map<String,String>	getAllPeerClusterKeys() List the cluster keys of all remote slave clusters (whether they are enabled/disabled or connected/disconnected).
List<String>	getAllPeerIds() List all registered peer clusters and set a watch on their znodes.
Set<String>	getConnectedPeers() Get a set of all connected remote slave clusters.
org.apache.hadoop.conf.Configuration	getPeerConf(String peerId) Returns the configuration needed to talk to the remote slave cluster.
UUID	getPeerUUID(String peerId) Returns the UUID of the provided peer id.
List<ServerName>	getRegionServersOfConnectedPeer(String peerId) Returns all region servers from given connected remote slave cluster.
boolean	getStatusOfConnectedPeer(String id) Get the replication status for the specified connected remote slave cluster.
boolean	getStatusOfPeerFromBackingStore(String id) Get the replication status for the specified remote slave cluster, which doesn't have to be connected.
long	getTimestampOfLastChangeToPeer(String peerId) Get the timestamp of the last change in composition of a given peer cluster.
void	init() Initialize the ReplicationPeers interface.
void	removePeer(String id) Removes a remote slave cluster and stops the replication to it.

Methods inherited from class org.apache.hadoop.hbase.replication.ReplicationStateZKBase

getListOfReplicators, isPeerPath, peerExists, toByteArray

Methods inherited from class java.lang.Object

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

Constructor Detail

ReplicationPeersZKImpl

public ReplicationPeersZKImpl(ZooKeeperWatcher zk,
                              org.apache.hadoop.conf.Configuration conf,
                              Abortable abortable)

Method Detail

init

public void init()
          throws IOException,
                 org.apache.zookeeper.KeeperException

Description copied from interface: ReplicationPeers

Initialize the ReplicationPeers interface.

Specified by:

init in interface ReplicationPeers

Throws:

org.apache.zookeeper.KeeperException

IOException

addPeer

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

Description copied from interface: ReplicationPeers

Add a new remote slave cluster for replication.

Specified by:

addPeer in interface ReplicationPeers

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:

IOException

removePeer

public void removePeer(String id)
                throws IOException

Description copied from interface: ReplicationPeers

Removes a remote slave cluster and stops the replication to it.

Specified by:

removePeer in interface ReplicationPeers

Parameters:

id - a short that identifies the cluster

Throws:

IOException

enablePeer

public void enablePeer(String id)
                throws IOException

Description copied from interface: ReplicationPeers

Restart the replication to the specified remote slave cluster.

Specified by:

enablePeer in interface ReplicationPeers

Parameters:

id - a short that identifies the cluster

Throws:

IOException

disablePeer

public void disablePeer(String id)
                 throws IOException

Description copied from interface: ReplicationPeers

Stop the replication to the specified remote slave cluster.

Specified by:

disablePeer in interface ReplicationPeers

Parameters:

id - a short that identifies the cluster

Throws:

IOException

getStatusOfConnectedPeer

public boolean getStatusOfConnectedPeer(String id)

Description copied from interface: ReplicationPeers

Get the replication status for the specified connected remote slave cluster. The value might be read from cache, so it is recommended to use ReplicationPeers.getStatusOfPeerFromBackingStore(String) if reading the state after enabling or disabling it.

Specified by:

getStatusOfConnectedPeer in interface ReplicationPeers

Parameters:

id - a short that identifies the cluster

Returns:

true if replication is enabled, false otherwise.

getStatusOfPeerFromBackingStore

public boolean getStatusOfPeerFromBackingStore(String id)
                                        throws IOException

Description copied from interface: ReplicationPeers

Get the replication status for the specified remote slave cluster, which doesn't have to be connected. The state is read directly from the backing store.

Specified by:

getStatusOfPeerFromBackingStore in interface ReplicationPeers

Parameters:

id - a short that identifies the cluster

Returns:

true if replication is enabled, false otherwise.

Throws:

IOException - Throws if there's an error contacting the store

connectToPeer

public boolean connectToPeer(String peerId)
                      throws IOException,
                             org.apache.zookeeper.KeeperException

Description copied from interface: ReplicationPeers

Attempt to connect to a new remote slave cluster.

Specified by:

connectToPeer in interface ReplicationPeers

Parameters:

peerId - a short that identifies the cluster

Returns:

true if a new connection was made, false if no new connection was made.

Throws:

IOException

org.apache.zookeeper.KeeperException

disconnectFromPeer

public void disconnectFromPeer(String peerId)

Description copied from interface: ReplicationPeers

Disconnect from a remote slave cluster.

Specified by:

disconnectFromPeer in interface ReplicationPeers

Parameters:

peerId - a short that identifies the cluster

getAllPeerClusterKeys

public Map<String,String> getAllPeerClusterKeys()

Description copied from interface: ReplicationPeers

List the cluster keys of all remote slave clusters (whether they are enabled/disabled or connected/disconnected).

Specified by:

getAllPeerClusterKeys in interface ReplicationPeers

Returns:

A map of peer ids to peer cluster keys

getRegionServersOfConnectedPeer

public List<ServerName> getRegionServersOfConnectedPeer(String peerId)

Description copied from interface: ReplicationPeers

Returns all region servers from given connected remote slave cluster.

Specified by:

getRegionServersOfConnectedPeer in interface ReplicationPeers

Parameters:

peerId - a short that identifies the cluster

Returns:

addresses of all region servers in the peer cluster. Returns an empty list if the peer cluster is unavailable or there are no region servers in the cluster.

getPeerUUID

public UUID getPeerUUID(String peerId)

Description copied from interface: ReplicationPeers

Returns the UUID of the provided peer id.

Specified by:

getPeerUUID in interface ReplicationPeers

Parameters:

peerId - the peer's ID that will be converted into a UUID

Returns:

a UUID or null if the peer cluster does not exist or is not connected.

getConnectedPeers

public Set<String> getConnectedPeers()

Description copied from interface: ReplicationPeers

Get a set of all connected remote slave clusters.

Specified by:

getConnectedPeers in interface ReplicationPeers

Returns:

set of peer ids

getPeerConf

public org.apache.hadoop.conf.Configuration getPeerConf(String peerId)
                                                 throws org.apache.zookeeper.KeeperException

Description copied from interface: ReplicationPeers

Returns the configuration needed to talk to the remote slave cluster.

Specified by:

getPeerConf in interface ReplicationPeers

Parameters:

peerId - a short that identifies the cluster

Returns:

the configuration for the peer cluster, null if it was unable to get the configuration

Throws:

org.apache.zookeeper.KeeperException

getAllPeerIds

public List<String> getAllPeerIds()

List all registered peer clusters and set a watch on their znodes.

Specified by:

getAllPeerIds in interface ReplicationPeers

Returns:

A list of peer ids

getTimestampOfLastChangeToPeer

public long getTimestampOfLastChangeToPeer(String peerId)

Description copied from interface: ReplicationPeers

Get the timestamp of the last change in composition of a given peer cluster.

Specified by:

getTimestampOfLastChangeToPeer in interface ReplicationPeers

Parameters:

peerId - identifier of the peer cluster for which the timestamp is requested

Returns:

the timestamp (in milliseconds) of the last change to the composition of the peer cluster