alluxio.master.journal

Class AsyncJournalWriter

java.lang.Object

alluxio.master.journal.AsyncJournalWriter

@ThreadSafe
public final class AsyncJournalWriter
extends Object

This enables async journal writing, as well as some batched journal flushing.

Constructor Summary

Constructors

Constructor and Description
AsyncJournalWriter(JournalWriter journalWriter, java.util.function.Supplier<Set<JournalSink>> journalSinks) Creates a AsyncJournalWriter.
AsyncJournalWriter(JournalWriter journalWriter, java.util.function.Supplier<Set<JournalSink>> journalSinks, String journalName) Creates a AsyncJournalWriter.

Method Summary

Modifier and Type	Method and Description
long	appendEntry(Journal.JournalEntry entry) Appends a Journal.JournalEntry for writing to the journal.
void	close() Closes the async writer.
void	flush(long targetCounter) Submits a ticket to flush thread and waits until ticket is served.
protected void	start()
protected void	stop()

Methods inherited from class java.lang.Object

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

Constructor Detail

AsyncJournalWriter

public AsyncJournalWriter(JournalWriter journalWriter,
                          java.util.function.Supplier<Set<JournalSink>> journalSinks)

Creates a AsyncJournalWriter.

Parameters:

journalWriter - a journal writer to write to

journalSinks - a supplier for journal sinks

AsyncJournalWriter

public AsyncJournalWriter(JournalWriter journalWriter,
                          java.util.function.Supplier<Set<JournalSink>> journalSinks,
                          String journalName)

Creates a AsyncJournalWriter.

Parameters:

journalWriter - a journal writer to write to

journalSinks - a supplier for journal sinks

journalName - the journal source name

Method Detail

appendEntry

public long appendEntry(Journal.JournalEntry entry)

Appends a Journal.JournalEntry for writing to the journal.

Parameters:

entry - the Journal.JournalEntry to append

Returns:

a counter for the entry, for flushing

close

public void close()

Closes the async writer. PS: It's not guaranteed for pending entries to be flushed. Use ::flush() for guaranteeing the entries have been flushed.

stop

protected void stop()

start

protected void start()

flush

public void flush(long targetCounter)
           throws IOException,
                  JournalClosedException

Submits a ticket to flush thread and waits until ticket is served. If the specified counter is already flushed, this is essentially a no-op.

Parameters:

targetCounter - the counter to flush

Throws:

IOException

JournalClosedException