alluxio.worker.block.allocator

Class GreedyAllocator

java.lang.Object

alluxio.worker.block.allocator.GreedyAllocator

All Implemented Interfaces:

Allocator

@NotThreadSafe
public final class GreedyAllocator
extends Object
implements Allocator

A greedy allocator that returns the first Storage dir fitting the size of block to allocate. This class serves as an example how to implement an allocator.

Nested Class Summary

Nested classes/interfaces inherited from interface alluxio.worker.block.allocator.Allocator

Allocator.Factory

Constructor Summary

Constructors

Constructor and Description
GreedyAllocator(BlockMetadataView view) Creates a new instance of GreedyAllocator.

Method Summary

Modifier and Type	Method and Description
StorageDirView	allocateBlockWithView(long sessionId, long blockSize, BlockStoreLocation location, BlockMetadataView metadataView, boolean skipReview) Allocates a block from the given block store location under a given view.

Methods inherited from class java.lang.Object

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

Constructor Detail

GreedyAllocator

public GreedyAllocator(BlockMetadataView view)

Creates a new instance of GreedyAllocator.

Parameters:

view - BlockMetadataView to pass to the allocator

Method Detail

allocateBlockWithView

public StorageDirView allocateBlockWithView(long sessionId,
                                            long blockSize,
                                            BlockStoreLocation location,
                                            BlockMetadataView metadataView,
                                            boolean skipReview)

Description copied from interface: Allocator

Allocates a block from the given block store location under a given view. The location can be a specific location, or BlockStoreLocation.anyTier() or BlockStoreLocation.anyDirInTier(String). TODO(jiacheng): Refactor Allocator interface to decouple Reviewer logic from Allocator. The proposed allocation will be reviewed by a Reviewer. The reviewer will check certain aspects of the allocation and may reject the allocation if it does not meet certain criteria. The parameter skipReview specifies whether the review should be skipped. The review should be skipped when we want the behavior of the allocator to be deterministic and do not want it to be affected by the reviewer. E.g. We just freed up some space in Alluxio and want the allocation to use the freed space.

Specified by:

allocateBlockWithView in interface Allocator

Parameters:

sessionId - the id of session to apply for the block allocation

blockSize - the size of block in bytes

location - the location in block store

metadataView - of the block metadata

skipReview - whether the review should be skipped

Returns:

a StorageDirView in which to create the temp block meta if success, null otherwise