alluxio.client.block

Class BlockStoreClient

java.lang.Object

alluxio.client.block.BlockStoreClient

@ThreadSafe
public final class BlockStoreClient
extends Object

Alluxio Block Store client. This is an internal client for all block level operations in Alluxio. An instance of this class can be obtained via BlockStoreClient constructors.

Method Summary

Modifier and Type	Method and Description
static BlockStoreClient	create(FileSystemContext context) Creates an Alluxio block store with default local hostname.
long	getCapacityBytes() Gets the total capacity of Alluxio's BlockStore.
Pair<WorkerNetAddress,BlockInStream.BlockInStreamSource>	getDataSourceAndType(BlockInfo info, URIStatus status, BlockLocationPolicy policy, Map<WorkerNetAddress,Long> failedWorkers) Gets the data source and type of data source of a block.
BlockInfo	getInfo(long blockId) Gets the block info of a block, if it exists.
BlockInStream	getInStream(BlockInfo info, InStreamOptions options, Map<WorkerNetAddress,Long> failedWorkers) getInStream(long, InStreamOptions, Map).
BlockInStream	getInStream(long blockId, InStreamOptions options) Gets a stream to read the data of a block.
BlockInStream	getInStream(long blockId, InStreamOptions options, Map<WorkerNetAddress,Long> failedWorkers) Gets a stream to read the data of a block.
BlockOutStream	getOutStream(long blockId, long blockSize, OutStreamOptions options) Gets a stream to write data to a block based on the options.
BlockOutStream	getOutStream(long blockId, long blockSize, WorkerNetAddress address, OutStreamOptions options) Gets a stream to write data to a block.
long	getUsedBytes() Gets the used bytes of Alluxio's BlockStore.

Methods inherited from class java.lang.Object

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

Method Detail

create

public static BlockStoreClient create(FileSystemContext context)

Creates an Alluxio block store with default local hostname.

Parameters:

context - the file system context

Returns:

the BlockStoreClient created

getInfo

public BlockInfo getInfo(long blockId)
                  throws IOException

Gets the block info of a block, if it exists.

Parameters:

blockId - the blockId to obtain information about

Returns:

a BlockInfo containing the metadata of the block

Throws:

IOException

getInStream

public BlockInStream getInStream(long blockId,
                                 InStreamOptions options)
                          throws IOException

Gets a stream to read the data of a block. This method is primarily responsible for determining the data source and type of data source. The latest BlockInfo will be fetched from the master to ensure the locations are up-to-date.

Parameters:

blockId - the id of the block to read

options - the options associated with the read request

Returns:

a stream which reads from the beginning of the block

Throws:

IOException

getInStream

public BlockInStream getInStream(long blockId,
                                 InStreamOptions options,
                                 Map<WorkerNetAddress,Long> failedWorkers)
                          throws IOException

Gets a stream to read the data of a block. This method is primarily responsible for determining the data source and type of data source. The latest BlockInfo will be fetched from the master to ensure the locations are up-to-date. It takes a map of failed workers and their most recently failed time and tries to update it when BlockInStream created failed, attempting to avoid reading from a recently failed worker.

Parameters:

blockId - the id of the block to read

options - the options associated with the read request

failedWorkers - the map of worker's addresses to most recent failure time

Returns:

a stream which reads from the beginning of the block

Throws:

IOException

getInStream

public BlockInStream getInStream(BlockInfo info,
                                 InStreamOptions options,
                                 Map<WorkerNetAddress,Long> failedWorkers)
                          throws IOException

getInStream(long, InStreamOptions, Map).

Parameters:

info - the block info

options - the options associated with the read request

failedWorkers - the map of worker's addresses to most recent failure time

Returns:

a stream which reads from the beginning of the block

Throws:

IOException

getDataSourceAndType

public Pair<WorkerNetAddress,BlockInStream.BlockInStreamSource> getDataSourceAndType(BlockInfo info,
                                                                                     URIStatus status,
                                                                                     BlockLocationPolicy policy,
                                                                                     Map<WorkerNetAddress,Long> failedWorkers)
                                                                              throws IOException

Gets the data source and type of data source of a block. This method is primarily responsible for determining the data source and type of data source. It takes a map of failed workers and their most recently failed time and tries to update it when BlockInStream created failed, attempting to avoid reading from a recently failed worker.

Parameters:

info - the info of the block to read

status - the URIStatus associated with the read request

policy - the policy determining the Alluxio worker location

failedWorkers - the map of worker's addresses to most recent failure time

Returns:

the data source and type of data source of the block

Throws:

IOException

getOutStream

public BlockOutStream getOutStream(long blockId,
                                   long blockSize,
                                   WorkerNetAddress address,
                                   OutStreamOptions options)
                            throws IOException

Gets a stream to write data to a block. The stream can only be backed by Alluxio storage.

Parameters:

blockId - the block to write

blockSize - the standard block size to write

address - the address of the worker to write the block to, fails if the worker cannot serve the request

options - the output stream options

Returns:

an BlockOutStream which can be used to write data to the block in a streaming fashion

Throws:

IOException

getOutStream

public BlockOutStream getOutStream(long blockId,
                                   long blockSize,
                                   OutStreamOptions options)
                            throws IOException

Gets a stream to write data to a block based on the options. The stream can only be backed by Alluxio storage.

Parameters:

blockId - the block to write

blockSize - the standard block size to write

options - the output stream option

Returns:

a BlockOutStream which can be used to write data to the block in a streaming fashion

Throws:

IOException

getCapacityBytes

public long getCapacityBytes()
                      throws IOException

Gets the total capacity of Alluxio's BlockStore.

Returns:

the capacity in bytes

Throws:

IOException

getUsedBytes

public long getUsedBytes()
                  throws IOException

Gets the used bytes of Alluxio's BlockStore.

Returns:

the used bytes of Alluxio's BlockStore

Throws:

IOException