alluxio.worker.block.allocator

Interface Allocator

All Known Implementing Classes:

GreedyAllocator, MaxFreeAllocator, RoundRobinAllocator

@PublicApi
public interface Allocator

Interface for the allocation policy of Alluxio managed data.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Allocator.Factory Factory for Allocator.

Method Summary

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

Method Detail

allocateBlockWithView

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

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.

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

view - 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