org.apache.flink.runtime.blob

Class BlobCache

java.lang.Object

org.apache.flink.runtime.blob.BlobCache

All Implemented Interfaces:

Closeable, AutoCloseable, BlobService

public final class BlobCache
extends Object
implements BlobService

The BLOB cache implements a local cache for content-addressable BLOBs.

When requesting BLOBs through the getURL(org.apache.flink.runtime.blob.BlobKey) methods, the BLOB cache will first attempt to serve the file from its local cache. Only if the local cache does not contain the desired BLOB, the BLOB cache will try to download it from a distributed file system (if available) or the BLOB server.

Constructor Summary

Constructors

Constructor and Description
BlobCache(InetSocketAddress serverAddress, Configuration blobClientConfig, BlobView blobView) Instantiates a new BLOB cache.

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
BlobClient	createClient()
void	delete(BlobKey key) Deletes the file associated with the given key from the BLOB cache.
void	deleteGlobal(BlobKey key) Deletes the file associated with the given key from the BLOB cache and BLOB server.
int	getPort() Returns the port of the blob service.
File	getStorageDir()
URL	getURL(BlobKey requiredBlob) Returns the URL for the BLOB with the given key.

Methods inherited from class java.lang.Object

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

Constructor Detail

BlobCache

public BlobCache(InetSocketAddress serverAddress,
         Configuration blobClientConfig,
         BlobView blobView)
          throws IOException

Instantiates a new BLOB cache.

Parameters:

serverAddress - address of the BlobServer to use for fetching files from

blobClientConfig - global configuration

blobView - (distributed) blob store file system to retrieve files from first

Throws:

IOException - thrown if the (local or distributed) file storage cannot be created or is not usable

Method Detail

getURL

public URL getURL(BlobKey requiredBlob)
           throws IOException

Returns the URL for the BLOB with the given key. The method will first attempt to serve the BLOB from its local cache. If the BLOB is not in the cache, the method will try to download it from this cache's BLOB server.

Specified by:

getURL in interface BlobService

Parameters:

requiredBlob - The key of the desired BLOB.

Returns:

URL referring to the local storage location of the BLOB.

Throws:

IOException - Thrown if an I/O error occurs while downloading the BLOBs from the BLOB server.

delete

public void delete(BlobKey key)
            throws IOException

Deletes the file associated with the given key from the BLOB cache.

Specified by:

delete in interface BlobService

Parameters:

key - referring to the file to be deleted

Throws:

IOException

deleteGlobal

public void deleteGlobal(BlobKey key)
                  throws IOException

Deletes the file associated with the given key from the BLOB cache and BLOB server.

Parameters:

key - referring to the file to be deleted

Throws:

IOException - thrown if an I/O error occurs while transferring the request to the BLOB server or if the BLOB server cannot delete the file

getPort

public int getPort()

Description copied from interface: BlobService

Returns the port of the blob service.

Specified by:

getPort in interface BlobService

Returns:

the port of the blob service.

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

createClient

public BlobClient createClient()
                        throws IOException

Specified by:

createClient in interface BlobService

Throws:

IOException

getStorageDir

public File getStorageDir()