Package org.apache.flink.core.fs

Class RecoverableFsDataOutputStream

java.lang.Object

java.io.OutputStream

org.apache.flink.core.fs.FSDataOutputStream

org.apache.flink.core.fs.RecoverableFsDataOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable

Direct Known Subclasses:

CommitterFromPersistRecoverableFsDataOutputStream

@PublicEvolving
public abstract class RecoverableFsDataOutputStream
extends FSDataOutputStream

An output stream to a file system that can be recovered at well defined points. The stream initially writes to hidden files or temp files and only creates the target file once it is closed and "committed".

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	RecoverableFsDataOutputStream.Committer	A committer can publish the file of a stream that was closed.

Constructor Summary

Constructors

Constructor	Description
RecoverableFsDataOutputStream()

Method Summary

Modifier and Type	Method	Description
abstract void	close()	Closes this stream.
abstract RecoverableFsDataOutputStream.Committer	closeForCommit()	Closes the stream, ensuring persistence of all data (similar to FSDataOutputStream.sync()).
abstract RecoverableWriter.ResumeRecoverable	persist()	Ensures all data so far is persistent (similar to FSDataOutputStream.sync()) and returns a handle to recover the stream at the current position.

Methods inherited from class org.apache.flink.core.fs.FSDataOutputStream

flush, getPos, sync

Methods inherited from class java.io.OutputStream

nullOutputStream, write, write, write

Methods inherited from class java.lang.Object

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

Constructor Detail

RecoverableFsDataOutputStream

public RecoverableFsDataOutputStream()

Method Detail

persist

public abstract RecoverableWriter.ResumeRecoverable persist()
                                                     throws IOException

Ensures all data so far is persistent (similar to FSDataOutputStream.sync()) and returns a handle to recover the stream at the current position.

Throws:

IOException

closeForCommit

public abstract RecoverableFsDataOutputStream.Committer closeForCommit()
                                                                throws IOException

Closes the stream, ensuring persistence of all data (similar to FSDataOutputStream.sync()). This returns a Committer that can be used to publish (make visible) the file that the stream was writing to.

Throws:

IOException

close

public abstract void close()
                    throws IOException

Closes this stream. Closing the steam releases the local resources that the stream uses, but does NOT result in durability of previously written data. This method should be interpreted as a "close in order to dispose" or "close on failure".

In order to persist all previously written data, one needs to call the closeForCommit() method and call RecoverableFsDataOutputStream.Committer.commit() on the returned committer object.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in class FSDataOutputStream

Throws:

IOException - Thrown if an error occurred during closing.