org.apache.hadoop.hdfs.protocolPB

Class NamenodeProtocolTranslatorPB

java.lang.Object

org.apache.hadoop.hdfs.protocolPB.NamenodeProtocolTranslatorPB

All Implemented Interfaces:

Closeable, AutoCloseable, NamenodeProtocol, ProtocolMetaInterface

@InterfaceAudience.Private
@InterfaceStability.Stable
public class NamenodeProtocolTranslatorPB
extends Object
implements NamenodeProtocol, ProtocolMetaInterface, Closeable

This class is the client side translator to translate the requests made on NamenodeProtocol interfaces to the RPC server implementing NamenodeProtocolPB.

Field Summary

Fields inherited from interface org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol

ACT_CHECKPOINT, ACT_SHUTDOWN, ACT_UNKNOWN, FATAL, NOTIFY, versionID

Constructor Summary

Constructors

Constructor and Description
NamenodeProtocolTranslatorPB(NamenodeProtocolPB rpcProxy)

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
void	endCheckpoint(NamenodeRegistration registration, CheckpointSignature sig) A request to the active name-node to finalize previously started checkpoint.
void	errorReport(NamenodeRegistration registration, int errorCode, String msg) Report to the active name-node an error occurred on a subordinate node.
ExportedBlockKeys	getBlockKeys() Get the current block keys
BlocksWithLocations	getBlocks(DatanodeInfo datanode, long size) Get a list of blocks belonging to datanode whose total size equals size.
RemoteEditLogManifest	getEditLogManifest(long sinceTxId) Return a structure containing details about all edit logs available to be fetched from the NameNode.
long	getMostRecentCheckpointTxId() Get the transaction ID of the most recent checkpoint.
long	getTransactionID()
boolean	isMethodSupported(String methodName) Checks whether the given method name is supported by the server.
NamenodeRegistration	registerSubordinateNamenode(NamenodeRegistration registration) Register a subordinate name-node like backup node.
CheckpointSignature	rollEditLog() Closes the current edit log and opens a new one.
NamenodeCommand	startCheckpoint(NamenodeRegistration registration) A request to the active name-node to start a checkpoint.
NamespaceInfo	versionRequest() Request name-node version and storage information.

Methods inherited from class java.lang.Object

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

Constructor Detail

NamenodeProtocolTranslatorPB

public NamenodeProtocolTranslatorPB(NamenodeProtocolPB rpcProxy)

Method Detail

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

getBlocks

public BlocksWithLocations getBlocks(DatanodeInfo datanode,
                            long size)
                              throws IOException

Description copied from interface: NamenodeProtocol

Get a list of blocks belonging to datanode whose total size equals size.

Specified by:

getBlocks in interface NamenodeProtocol

Parameters:

datanode - a data node

size - requested size

Returns:

a list of blocks & their locations

Throws:

IOException - if size is less than or equal to 0 or datanode does not exist

See Also:

Balancer

getBlockKeys

public ExportedBlockKeys getBlockKeys()
                               throws IOException

Description copied from interface: NamenodeProtocol

Get the current block keys

Specified by:

getBlockKeys in interface NamenodeProtocol

Returns:

ExportedBlockKeys containing current block keys

Throws:

IOException

getTransactionID

public long getTransactionID()
                      throws IOException

Specified by:

getTransactionID in interface NamenodeProtocol

Returns:

The most recent transaction ID that has been synced to persistent storage, or applied from persistent storage in the case of a non-active node.

Throws:

IOException

getMostRecentCheckpointTxId

public long getMostRecentCheckpointTxId()
                                 throws IOException

Description copied from interface: NamenodeProtocol

Get the transaction ID of the most recent checkpoint.

Specified by:

getMostRecentCheckpointTxId in interface NamenodeProtocol

Throws:

IOException

rollEditLog

public CheckpointSignature rollEditLog()
                                throws IOException

Description copied from interface: NamenodeProtocol

Closes the current edit log and opens a new one. The call fails if the file system is in SafeMode.

Specified by:

rollEditLog in interface NamenodeProtocol

Returns:

a unique token to identify this transaction.

Throws:

IOException

versionRequest

public NamespaceInfo versionRequest()
                             throws IOException

Description copied from interface: NamenodeProtocol

Request name-node version and storage information.

Specified by:

versionRequest in interface NamenodeProtocol

Returns:

NamespaceInfo identifying versions and storage information of the name-node

Throws:

IOException

errorReport

public void errorReport(NamenodeRegistration registration,
               int errorCode,
               String msg)
                 throws IOException

Description copied from interface: NamenodeProtocol

Report to the active name-node an error occurred on a subordinate node. Depending on the error code the active node may decide to unregister the reporting node.

Specified by:

errorReport in interface NamenodeProtocol

Parameters:

registration - requesting node.

errorCode - indicates the error

msg - free text description of the error

Throws:

IOException

registerSubordinateNamenode

public NamenodeRegistration registerSubordinateNamenode(NamenodeRegistration registration)
                                                 throws IOException

Description copied from interface: NamenodeProtocol

Register a subordinate name-node like backup node.

Specified by:

registerSubordinateNamenode in interface NamenodeProtocol

Returns:

NamenodeRegistration of the node, which this node has just registered with.

Throws:

IOException

startCheckpoint

public NamenodeCommand startCheckpoint(NamenodeRegistration registration)
                                throws IOException

Description copied from interface: NamenodeProtocol

A request to the active name-node to start a checkpoint. The name-node should decide whether to admit it or reject. The name-node also decides what should be done with the backup node image before and after the checkpoint.

Specified by:

startCheckpoint in interface NamenodeProtocol

Parameters:

registration - the requesting node

Returns:

CheckpointCommand if checkpoint is allowed.

Throws:

IOException

See Also:

CheckpointCommand, NamenodeCommand, NamenodeProtocol.ACT_SHUTDOWN

endCheckpoint

public void endCheckpoint(NamenodeRegistration registration,
                 CheckpointSignature sig)
                   throws IOException

Description copied from interface: NamenodeProtocol

A request to the active name-node to finalize previously started checkpoint.

Specified by:

endCheckpoint in interface NamenodeProtocol

Parameters:

registration - the requesting node

sig - CheckpointSignature which identifies the checkpoint.

Throws:

IOException

getEditLogManifest

public RemoteEditLogManifest getEditLogManifest(long sinceTxId)
                                         throws IOException

Description copied from interface: NamenodeProtocol

Return a structure containing details about all edit logs available to be fetched from the NameNode.

Specified by:

getEditLogManifest in interface NamenodeProtocol

Parameters:

sinceTxId - return only logs that contain transactions >= sinceTxId

Throws:

IOException

isMethodSupported

public boolean isMethodSupported(String methodName)
                          throws IOException

Description copied from interface: ProtocolMetaInterface

Checks whether the given method name is supported by the server. It is assumed that all method names are unique for a protocol.

Specified by:

isMethodSupported in interface ProtocolMetaInterface

Parameters:

methodName - The name of the method

Returns:

true if method is supported, otherwise false.

Throws:

IOException