org.apache.hadoop.hdfs.protocolPB

Class JournalProtocolTranslatorPB

java.lang.Object

org.apache.hadoop.hdfs.protocolPB.JournalProtocolTranslatorPB

All Implemented Interfaces:

Closeable, AutoCloseable, JournalProtocol, ProtocolMetaInterface

@InterfaceAudience.Private
@InterfaceStability.Stable
public class JournalProtocolTranslatorPB
extends Object
implements ProtocolMetaInterface, JournalProtocol, Closeable

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

Field Summary

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

versionID

Constructor Summary

Constructors

Constructor and Description
JournalProtocolTranslatorPB(JournalProtocolPB rpcProxy)

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
FenceResponse	fence(JournalInfo journalInfo, long epoch, String fencerInfo) Request to fence any other journal writers.
boolean	isMethodSupported(String methodName) Checks whether the given method name is supported by the server.
void	journal(JournalInfo journalInfo, long epoch, long firstTxnId, int numTxns, byte[] records) Journal edit records.
void	startLogSegment(JournalInfo journalInfo, long epoch, long txid) Notify the BackupNode that the NameNode has rolled its edit logs and is now writing a new log segment.

Methods inherited from class java.lang.Object

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

Constructor Detail

JournalProtocolTranslatorPB

public JournalProtocolTranslatorPB(JournalProtocolPB rpcProxy)

Method Detail

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

journal

public void journal(JournalInfo journalInfo,
           long epoch,
           long firstTxnId,
           int numTxns,
           byte[] records)
             throws IOException

Description copied from interface: JournalProtocol

Journal edit records. This message is sent by the active name-node to the backup node via EditLogBackupOutputStream in order to synchronize meta-data changes with the backup namespace image.

Specified by:

journal in interface JournalProtocol

Parameters:

journalInfo - journal information

epoch - marks beginning a new journal writer

firstTxnId - the first transaction of this batch

numTxns - number of transactions

records - byte array containing serialized journal records

Throws:

FencedException - if the resource has been fenced

IOException

startLogSegment

public void startLogSegment(JournalInfo journalInfo,
                   long epoch,
                   long txid)
                     throws IOException

Description copied from interface: JournalProtocol

Notify the BackupNode that the NameNode has rolled its edit logs and is now writing a new log segment.

Specified by:

startLogSegment in interface JournalProtocol

Parameters:

journalInfo - journal information

epoch - marks beginning a new journal writer

txid - the first txid in the new log

Throws:

FencedException - if the resource has been fenced

IOException

fence

public FenceResponse fence(JournalInfo journalInfo,
                  long epoch,
                  String fencerInfo)
                    throws IOException

Description copied from interface: JournalProtocol

Request to fence any other journal writers. Older writers with at previous epoch will be fenced and can no longer perform journal operations.

Specified by:

fence in interface JournalProtocol

Parameters:

journalInfo - journal information

epoch - marks beginning a new journal writer

fencerInfo - info about fencer for debugging purposes

Throws:

FencedException - if the resource has been fenced

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