org.apache.flink.runtime.checkpoint.savepoint

Class SavepointStore

java.lang.Object

org.apache.flink.runtime.checkpoint.savepoint.SavepointStore

public class SavepointStore
extends Object

Utilities for storing and loading savepoint meta data files.

Stored savepoints have the following format:

 MagicNumber SavepointVersion Savepoint
   - MagicNumber => int
   - SavepointVersion => int (returned by Savepoint#getVersion())
   - Savepoint => bytes (serialized via version-specific SavepointSerializer)
 

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAGIC_NUMBER Magic number for sanity checks against stored savepoints.

Constructor Summary

Constructors

Constructor and Description
SavepointStore()

Method Summary

Modifier and Type	Method and Description
static String	createSavepointDirectory(String baseDirectory, JobID jobId) Creates a savepoint directory.
static void	deleteSavepointDirectory(String savepointDirectory) Deletes a savepoint directory.
static Savepoint	loadSavepoint(String savepointFileOrDirectory, ClassLoader classLoader) Loads the savepoint at the specified path.
static Tuple2<Savepoint,StreamStateHandle>	loadSavepointWithHandle(String savepointFileOrDirectory, ClassLoader classLoader) Loads the savepoint at the specified path.
static void	removeSavepointFile(String path) Removes the savepoint meta data w/o loading and disposing it.
static <T extends Savepoint> FileStateHandle	storeExternalizedCheckpointToHandle(String directory, T savepoint) Stores the externalized checkpoint metadata file to a state handle.
static <T extends Savepoint> String	storeSavepoint(String directory, T savepoint) Stores the savepoint metadata file.
static <T extends Savepoint> FileStateHandle	storeSavepointToHandle(String directory, T savepoint) Stores the savepoint metadata file to a state handle.

Methods inherited from class java.lang.Object

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

Field Detail

MAGIC_NUMBER

public static final int MAGIC_NUMBER

Magic number for sanity checks against stored savepoints.

See Also:

Constant Field Values

Constructor Detail

SavepointStore

public SavepointStore()

Method Detail

createSavepointDirectory

public static String createSavepointDirectory(@Nonnull
                                              String baseDirectory,
                                              @Nullable
                                              JobID jobId)
                                       throws IOException

Creates a savepoint directory.

Parameters:

baseDirectory - Base target directory for the savepoint

jobId - Optional JobID the savepoint belongs to

Returns:

The created savepoint directory

Throws:

IOException - FileSystem operation failures are forwarded

deleteSavepointDirectory

public static void deleteSavepointDirectory(@Nonnull
                                            String savepointDirectory)
                                     throws IOException

Deletes a savepoint directory.

Parameters:

savepointDirectory - Recursively deletes the given directory

Throws:

IOException - FileSystem operation failures are forwarded

storeSavepoint

public static <T extends Savepoint> String storeSavepoint(String directory,
                                                          T savepoint)
                                                   throws IOException

Stores the savepoint metadata file.

Type Parameters:

T - Savepoint type

Parameters:

directory - Target directory to store savepoint in

savepoint - Savepoint to be stored

Returns:

Path of stored savepoint

Throws:

IOException - Failures during store are forwarded

storeSavepointToHandle

public static <T extends Savepoint> FileStateHandle storeSavepointToHandle(String directory,
                                                                           T savepoint)
                                                                    throws IOException

Stores the savepoint metadata file to a state handle.

Parameters:

directory - Target directory to store savepoint in

savepoint - Savepoint to be stored

Returns:

State handle to the checkpoint metadata

Throws:

IOException - Failures during store are forwarded

storeExternalizedCheckpointToHandle

public static <T extends Savepoint> FileStateHandle storeExternalizedCheckpointToHandle(String directory,
                                                                                        T savepoint)
                                                                                 throws IOException

Stores the externalized checkpoint metadata file to a state handle.

Parameters:

directory - Target directory to store savepoint in

savepoint - Savepoint to be stored

Returns:

State handle to the checkpoint metadata

Throws:

IOException - Failures during store are forwarded

loadSavepoint

public static Savepoint loadSavepoint(String savepointFileOrDirectory,
                                      ClassLoader classLoader)
                               throws IOException

Loads the savepoint at the specified path.

Parameters:

savepointFileOrDirectory - Path to the parent savepoint directory or the meta data file.

classLoader - The class loader used to resolve serialized classes from legacy savepoint formats.

Returns:

The loaded savepoint

Throws:

IOException - Failures during load are forwarded

loadSavepointWithHandle

public static Tuple2<Savepoint,StreamStateHandle> loadSavepointWithHandle(String savepointFileOrDirectory,
                                                                          ClassLoader classLoader)
                                                                   throws IOException

Loads the savepoint at the specified path. This methods returns the savepoint, as well as the handle to the metadata.

Parameters:

savepointFileOrDirectory - Path to the parent savepoint directory or the meta data file.

classLoader - The class loader used to resolve serialized classes from legacy savepoint formats.

Returns:

The loaded savepoint

Throws:

IOException - Failures during load are forwarded

removeSavepointFile

public static void removeSavepointFile(String path)
                                throws IOException

Removes the savepoint meta data w/o loading and disposing it.

Parameters:

path - Path of savepoint to remove

Throws:

IOException - Failures during disposal are forwarded