org.apache.flink.runtime.blob

Class BlobServer

java.lang.Object

java.lang.Thread

org.apache.flink.runtime.blob.BlobServer

All Implemented Interfaces:

Closeable, AutoCloseable, Runnable, BlobService

public class BlobServer
extends Thread
implements BlobService

This class implements the BLOB server. The BLOB server is responsible for listening for incoming requests and spawning threads to handle these requests. Furthermore, it takes care of creating the directory structure to store the BLOBs or temporarily cache them.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
BlobServer(Configuration config, BlobStore blobStore) Instantiates a new BLOB server and binds it to a free network port.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Shuts down the BLOB server.
BlobClient	createClient()
void	delete(BlobKey key) This method deletes the file associated to the blob key if it exists in the local storage of the blob server.
int	getPort() Returns the port on which the server is listening.
ReadWriteLock	getReadWriteLock() Returns the lock used to guard file accesses
URL	getURL(BlobKey requiredBlob) Method which retrieves the URL of a file associated with a blob key.
boolean	isShutdown() Tests whether the BLOB server has been requested to shut down.
void	run()

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

BlobServer

public BlobServer(Configuration config,
          BlobStore blobStore)
           throws IOException

Instantiates a new BLOB server and binds it to a free network port.

Parameters:

config - Configuration to be used to instantiate the BlobServer

blobStore - BlobStore to store blobs persistently

Throws:

IOException - thrown if the BLOB server cannot bind to a free network port or if the (local or distributed) file storage cannot be created or is not usable

Method Detail

getReadWriteLock

public ReadWriteLock getReadWriteLock()

Returns the lock used to guard file accesses

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

close

public void close()
           throws IOException

Shuts down the BLOB server.

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

getURL

public URL getURL(BlobKey requiredBlob)
           throws IOException

Method which retrieves the URL of a file associated with a blob key. The blob server looks the blob key up in its local storage. If the file exists, then the URL is returned. If the file does not exist, then a FileNotFoundException is thrown.

Specified by:

getURL in interface BlobService

Parameters:

requiredBlob - blob key associated with the requested file

Returns:

URL of the file

Throws:

IOException

delete

public void delete(BlobKey key)
            throws IOException

This method deletes the file associated to the blob key if it exists in the local storage of the blob server.

Specified by:

delete in interface BlobService

Parameters:

key - associated with the file to be deleted

Throws:

IOException

getPort

public int getPort()

Returns the port on which the server is listening.

Specified by:

getPort in interface BlobService

Returns:

port on which the server is listening

isShutdown

public boolean isShutdown()

Tests whether the BLOB server has been requested to shut down.

Returns:

True, if the server has been requested to shut down, false otherwise.