Package org.apache.hadoop.hdfs.qjournal.client

Class QuorumJournalManager

java.lang.Object

org.apache.hadoop.hdfs.qjournal.client.QuorumJournalManager

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, Storage.FormatConfirmable, JournalManager

@Private
public class QuorumJournalManager
extends java.lang.Object
implements JournalManager

A JournalManager that writes to a set of remote JournalNodes, requiring a quorum of nodes to ack each write.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.hdfs.server.namenode.JournalManager

JournalManager.CorruptionException

Field Summary

Fields

Modifier and Type	Field	Description
static int	QJM_RPC_MAX_TXNS_DEFAULT
static java.lang.String	QJM_RPC_MAX_TXNS_KEY

Constructor Summary

Constructors

Constructor	Description
QuorumJournalManager(org.apache.hadoop.conf.Configuration conf, java.net.URI uri, NamespaceInfo nsInfo)
QuorumJournalManager(org.apache.hadoop.conf.Configuration conf, java.net.URI uri, NamespaceInfo nsInfo, java.lang.String nameServiceId)

Method Summary

Modifier and Type	Method	Description
boolean	canRollBack(StorageInfo storage, StorageInfo prevStorage, int targetLayoutVersion)	Return true if this JM can roll back to the previous storage state, false otherwise.
static void	checkJournalId(java.lang.String jid)
void	close()	Close the journal manager, freeing any resources it may hold.
protected java.util.List<org.apache.hadoop.hdfs.qjournal.client.AsyncLogger>	createLoggers(org.apache.hadoop.hdfs.qjournal.client.AsyncLogger.Factory factory)
void	discardSegments(long startTxId)	Discard the segments whose first txid is >= the given txid.
void	doFinalize()	Finalize the upgrade.
void	doPreUpgrade()	Perform any steps that must succeed across all JournalManagers involved in an upgrade before proceeding onto the actual upgrade stage.
void	doRollback()	Perform the rollback to the previous FS state.
void	doUpgrade(Storage storage)	Perform the actual upgrade of the JM.
void	finalizeLogSegment(long firstTxId, long lastTxId)	Mark the log segment that spans from firstTxId to lastTxId as finalized and complete.
void	format(NamespaceInfo nsInfo, boolean force)	Format the underlying storage, removing any previously stored data.
long	getJournalCTime()
boolean	hasSomeData()
void	purgeLogsOlderThan(long minTxIdToKeep)
void	recoverUnfinalizedSegments()	Recover segments which have not been finalized.
void	selectInputStreams(java.util.Collection<EditLogInputStream> streams, long fromTxnId, boolean inProgressOk)
void	selectInputStreams(java.util.Collection<EditLogInputStream> streams, long fromTxnId, boolean inProgressOk, boolean onlyDurableTxns)
void	setOutputBufferCapacity(int size)	Set the amount of memory that this stream should use to buffer edits
EditLogOutputStream	startLogSegment(long txId, int layoutVersion)	Begin writing to a new segment of the log stream, which starts at the given transaction ID.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

QJM_RPC_MAX_TXNS_KEY

public static final java.lang.String QJM_RPC_MAX_TXNS_KEY

See Also:

Constant Field Values

QJM_RPC_MAX_TXNS_DEFAULT

public static final int QJM_RPC_MAX_TXNS_DEFAULT

See Also:

Constant Field Values

Constructor Detail

QuorumJournalManager

@VisibleForTesting
public QuorumJournalManager(org.apache.hadoop.conf.Configuration conf,
                            java.net.URI uri,
                            NamespaceInfo nsInfo)
                     throws java.io.IOException

Throws:

java.io.IOException

QuorumJournalManager

public QuorumJournalManager(org.apache.hadoop.conf.Configuration conf,
                            java.net.URI uri,
                            NamespaceInfo nsInfo,
                            java.lang.String nameServiceId)
                     throws java.io.IOException

Throws:

java.io.IOException

Method Detail

createLoggers

protected java.util.List<org.apache.hadoop.hdfs.qjournal.client.AsyncLogger> createLoggers(org.apache.hadoop.hdfs.qjournal.client.AsyncLogger.Factory factory)
                                                                                    throws java.io.IOException

Throws:

java.io.IOException

checkJournalId

public static void checkJournalId(java.lang.String jid)

format

public void format(NamespaceInfo nsInfo,
                   boolean force)
            throws java.io.IOException

Description copied from interface: JournalManager

Format the underlying storage, removing any previously stored data.

Specified by:

format in interface JournalManager

Throws:

java.io.IOException

hasSomeData

public boolean hasSomeData()
                    throws java.io.IOException

Specified by:

hasSomeData in interface Storage.FormatConfirmable

Returns:

true if the storage seems to have some valid data in it, and the user should be required to confirm the format. Otherwise, false.

Throws:

java.io.IOException - if the storage cannot be accessed at all.

startLogSegment

public EditLogOutputStream startLogSegment(long txId,
                                           int layoutVersion)
                                    throws java.io.IOException

Description copied from interface: JournalManager

Begin writing to a new segment of the log stream, which starts at the given transaction ID.

Specified by:

startLogSegment in interface JournalManager

Throws:

java.io.IOException

finalizeLogSegment

public void finalizeLogSegment(long firstTxId,
                               long lastTxId)
                        throws java.io.IOException

Description copied from interface: JournalManager

Mark the log segment that spans from firstTxId to lastTxId as finalized and complete.

Specified by:

finalizeLogSegment in interface JournalManager

Throws:

java.io.IOException

setOutputBufferCapacity

public void setOutputBufferCapacity(int size)

Description copied from interface: JournalManager

Set the amount of memory that this stream should use to buffer edits

Specified by:

setOutputBufferCapacity in interface JournalManager

purgeLogsOlderThan

public void purgeLogsOlderThan(long minTxIdToKeep)
                        throws java.io.IOException

Throws:

java.io.IOException

recoverUnfinalizedSegments

public void recoverUnfinalizedSegments()
                                throws java.io.IOException

Description copied from interface: JournalManager

Recover segments which have not been finalized.

Specified by:

recoverUnfinalizedSegments in interface JournalManager

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Description copied from interface: JournalManager

Close the journal manager, freeing any resources it may hold.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface JournalManager

Throws:

java.io.IOException

selectInputStreams

public void selectInputStreams(java.util.Collection<EditLogInputStream> streams,
                               long fromTxnId,
                               boolean inProgressOk)
                        throws java.io.IOException

Throws:

java.io.IOException

selectInputStreams

public void selectInputStreams(java.util.Collection<EditLogInputStream> streams,
                               long fromTxnId,
                               boolean inProgressOk,
                               boolean onlyDurableTxns)
                        throws java.io.IOException

Throws:

java.io.IOException

toString

public java.lang.String toString()

Specified by:

toString in interface Storage.FormatConfirmable

Overrides:

toString in class java.lang.Object

Returns:

a string representation of the formattable item, suitable for display to the user inside a prompt

doPreUpgrade

public void doPreUpgrade()
                  throws java.io.IOException

Description copied from interface: JournalManager

Perform any steps that must succeed across all JournalManagers involved in an upgrade before proceeding onto the actual upgrade stage. If a call to any JM's doPreUpgrade method fails, then doUpgrade will not be called for any JM.

Specified by:

doPreUpgrade in interface JournalManager

Throws:

java.io.IOException

doUpgrade

public void doUpgrade(Storage storage)
               throws java.io.IOException

Description copied from interface: JournalManager

Perform the actual upgrade of the JM. After this is completed, the NN can begin to use the new upgraded metadata. This metadata may later be either finalized or rolled back to the previous state.

Specified by:

doUpgrade in interface JournalManager

Parameters:

storage - info about the new upgraded versions.

Throws:

java.io.IOException

doFinalize

public void doFinalize()
                throws java.io.IOException

Description copied from interface: JournalManager

Finalize the upgrade. JMs should purge any state that they had been keeping around during the upgrade process. After this is completed, rollback is no longer allowed.

Specified by:

doFinalize in interface JournalManager

Throws:

java.io.IOException

canRollBack

public boolean canRollBack(StorageInfo storage,
                           StorageInfo prevStorage,
                           int targetLayoutVersion)
                    throws java.io.IOException

Description copied from interface: JournalManager

Return true if this JM can roll back to the previous storage state, false otherwise. The NN will refuse to run the rollback operation unless at least one JM or fsimage storage directory can roll back.

Specified by:

canRollBack in interface JournalManager

Parameters:

storage - the storage info for the current state

prevStorage - the storage info for the previous (unupgraded) state

targetLayoutVersion - the layout version we intend to roll back to

Returns:

true if this JM can roll back, false otherwise.

Throws:

java.io.IOException

doRollback

public void doRollback()
                throws java.io.IOException

Description copied from interface: JournalManager

Perform the rollback to the previous FS state. JMs which do not need to roll back their state should just return without error.

Specified by:

doRollback in interface JournalManager

Throws:

java.io.IOException

discardSegments

public void discardSegments(long startTxId)
                     throws java.io.IOException

Description copied from interface: JournalManager

Discard the segments whose first txid is >= the given txid.

Specified by:

discardSegments in interface JournalManager

Parameters:

startTxId - The given txid should be right at the segment boundary, i.e., it should be the first txid of some segment, if segment corresponding to the txid exists.

Throws:

java.io.IOException

getJournalCTime

public long getJournalCTime()
                     throws java.io.IOException

Specified by:

getJournalCTime in interface JournalManager

Returns:

the CTime of the journal manager.

Throws:

java.io.IOException