Package org.apache.hadoop.hdfs.server.datanode.fsdataset

Interface FsVolumeSpi

All Superinterfaces:

Checkable<FsVolumeSpi.VolumeCheckContext,VolumeCheckResult>

All Known Implementing Classes:

FsVolumeImpl

public interface FsVolumeSpi
extends Checkable<FsVolumeSpi.VolumeCheckContext,VolumeCheckResult>

This is an interface for the underlying volume.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	FsVolumeSpi.BlockIterator	BlockIterator will return ExtendedBlock entries from a block pool in this volume.
static class	FsVolumeSpi.ScanInfo	Tracks the files and other information related to a block on the disk Missing file is indicated by setting the corresponding member to null.
static class	FsVolumeSpi.VolumeCheckContext	Context for the Checkable.check(K) call.

Method Summary

Modifier and Type	Method	Description
void	compileReport(String bpid, Collection<FsVolumeSpi.ScanInfo> report, DirectoryScanner.ReportCompiler reportCompiler)	Compile a list of FsVolumeSpi.ScanInfo for the blocks in the block pool with id bpid.
long	getAvailable()
URI	getBaseURI()
String[]	getBlockPoolList()
FsDatasetSpi	getDataset()	Get the FSDatasetSpi which this volume is a part of.
FileIoProvider	getFileIoProvider()
DataNodeVolumeMetrics	getMetrics()
String	getStorageID()
StorageLocation	getStorageLocation()
org.apache.hadoop.fs.StorageType	getStorageType()
org.apache.hadoop.fs.DF	getUsageStats(org.apache.hadoop.conf.Configuration conf)
boolean	isRAMStorage()	Returns true if the volume is backed by RAM storage.
boolean	isTransientStorage()	Returns true if the volume is NOT backed by persistent storage.
FsVolumeSpi.BlockIterator	loadBlockIterator(String bpid, String name)	Load a saved block iterator.
byte[]	loadLastPartialChunkChecksum(File blockFile, File metaFile)	Load last partial chunk checksum from checksum file.
FsVolumeSpi.BlockIterator	newBlockIterator(String bpid, String name)	Create a new block iterator.
FsVolumeReference	obtainReference()	Obtain a reference object that had increased 1 reference count of the volume.
void	releaseLockedMemory(long bytesToRelease)	Release reserved memory for an RBW block written to transient storage i.e.
void	releaseReservedSpace(long bytesToRelease)	Release disk space previously reserved for block opened for write.
void	reserveSpaceForReplica(long bytesToReserve)	Reserve disk space for a block (RBW or Re-replicating) so a writer does not run out of space before the block is full.

Methods inherited from interface org.apache.hadoop.hdfs.server.datanode.checker.Checkable

check

Method Details

obtainReference

FsVolumeReference obtainReference()
                           throws ClosedChannelException

Obtain a reference object that had increased 1 reference count of the volume. It is caller's responsibility to close FsVolumeReference to decrease the reference count on the volume.

Throws:

ClosedChannelException

getStorageID

String getStorageID()

Returns:

the StorageUuid of the volume

getBlockPoolList

String[] getBlockPoolList()

Returns:

a list of block pools.

getAvailable

long getAvailable()
           throws IOException

Returns:

the available storage space in bytes.

Throws:

IOException

getBaseURI

URI getBaseURI()

Returns:

the base path to the volume

getUsageStats

org.apache.hadoop.fs.DF getUsageStats(org.apache.hadoop.conf.Configuration conf)

getStorageLocation

StorageLocation getStorageLocation()

Returns:

the StorageLocation to the volume

getStorageType

org.apache.hadoop.fs.StorageType getStorageType()

Returns:

the StorageType of the volume

isTransientStorage

boolean isTransientStorage()

Returns true if the volume is NOT backed by persistent storage.

isRAMStorage

boolean isRAMStorage()

Returns true if the volume is backed by RAM storage.

reserveSpaceForReplica

void reserveSpaceForReplica(long bytesToReserve)

Reserve disk space for a block (RBW or Re-replicating) so a writer does not run out of space before the block is full.

releaseReservedSpace

void releaseReservedSpace(long bytesToRelease)

Release disk space previously reserved for block opened for write.

releaseLockedMemory

void releaseLockedMemory(long bytesToRelease)

Release reserved memory for an RBW block written to transient storage i.e. RAM. bytesToRelease will be rounded down to the OS page size since locked memory reservation must always be a multiple of the page size.

newBlockIterator

FsVolumeSpi.BlockIterator newBlockIterator(String bpid,
 String name)

Create a new block iterator. It will start at the beginning of the block set.

Parameters:

bpid - The block pool id to iterate over.

name - The name of the block iterator to create.

Returns:

The new block iterator.

loadBlockIterator

FsVolumeSpi.BlockIterator loadBlockIterator(String bpid,
 String name)
                                     throws IOException

Load a saved block iterator.

Parameters:

bpid - The block pool id to iterate over.

name - The name of the block iterator to load.

Returns:

The saved block iterator.

Throws:

IOException - If there was an IO error loading the saved block iterator.

getDataset

FsDatasetSpi getDataset()

Get the FSDatasetSpi which this volume is a part of.

loadLastPartialChunkChecksum

byte[] loadLastPartialChunkChecksum(File blockFile,
 File metaFile)
                             throws IOException

Load last partial chunk checksum from checksum file. Need to be called with FsDataset lock acquired.

Parameters:

blockFile -

metaFile -

Returns:

the last partial checksum

Throws:

IOException

compileReport

void compileReport(String bpid,
 Collection<FsVolumeSpi.ScanInfo> report,
 DirectoryScanner.ReportCompiler reportCompiler)
            throws InterruptedException,
IOException

Compile a list of FsVolumeSpi.ScanInfo for the blocks in the block pool with id bpid.

Parameters:

bpid - block pool id to scan

report - the list onto which blocks reports are placed

reportCompiler -

Throws:

InterruptedException

IOException

getFileIoProvider

FileIoProvider getFileIoProvider()

getMetrics

DataNodeVolumeMetrics getMetrics()