org.apache.cassandra.db

Class Directories

java.lang.Object

org.apache.cassandra.db.Directories

public class Directories
extends java.lang.Object

Encapsulate handling of paths to the data files. Since v2.1, the directory layout is the following:

 
   /<path_to_data_dir>/ks/cf1-cfId/ks-cf1-ka-1-Data.db
                         /cf2-cfId/ks-cf2-ka-1-Data.db
                         ...
  

cfId is an hex encoded CFID. For backward compatibility, Directories uses older directory layout if exists. In addition, more that one 'root' data directory can be specified so that <path_to_data_dir> potentially represents multiple locations. Note that in the case of multiple locations, the manifest for the leveled compaction is only in one of the location. Snapshots (resp. backups) are always created along the sstables thare are snapshoted (resp. backuped) but inside a subdirectory named 'snapshots' (resp. backups) (and snapshots are furter inside a subdirectory of the name of the snapshot). This class abstracts all those details from the rest of the code.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Directories.DataDirectory
static class	Directories.FileAction
class	Directories.SSTableLister

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	BACKUPS_SUBDIR
static Directories.DataDirectory[]	dataDirectories
static java.lang.String	SECONDARY_INDEX_NAME_SEPARATOR
static java.lang.String	SNAPSHOT_SUBDIR

Constructor Summary

Constructors

Constructor and Description
Directories(CFMetaData metadata) Create Directories of given ColumnFamily.

Method Summary

Modifier and Type	Method and Description
static void	clearSnapshot(java.lang.String snapshotName, java.util.List<java.io.File> snapshotDirectories)
Descriptor	find(java.lang.String filename)
static java.io.File	getBackupsDirectory(Descriptor desc)
static java.io.File	getBackupsDirectory(java.io.File location)
java.util.List<java.io.File>	getCFDirectories()
java.io.File	getDirectoryForNewSSTables() Basically the same as calling getWriteableLocationAsFile(long) with an unknown size (-1L), which may return any non-blacklisted directory - even a data directory that has no usable space.
static java.util.List<java.io.File>	getKSChildDirectories(java.lang.String ksName)
java.io.File	getLocationForDisk(Directories.DataDirectory dataDirectory) Returns SSTable location which is inside given data directory.
java.util.Map<java.lang.String,Pair<java.lang.Long,java.lang.Long>>	getSnapshotDetails()
static java.io.File	getSnapshotDirectory(Descriptor desc, java.lang.String snapshotName)
static java.io.File	getSnapshotDirectory(java.io.File location, java.lang.String snapshotName)
java.io.File	getSnapshotManifestFile(java.lang.String snapshotName)
long	getTrueAllocatedSizeIn(java.io.File input)
Directories.DataDirectory	getWriteableLocation(long writeSize) Returns a non-blacklisted data directory that _currently_ has writeSize bytes as usable space.
java.io.File	getWriteableLocationAsFile(long writeSize) Returns a non-blacklisted data directory that _currently_ has writeSize bytes as usable space.
boolean	hasAvailableDiskSpace(long estimatedSSTables, long expectedTotalWriteSize)
long	snapshotCreationTime(java.lang.String snapshotName)
boolean	snapshotExists(java.lang.String snapshotName)
Directories.SSTableLister	sstableLister()
long	trueSnapshotsSize()
static boolean	verifyFullPermissions(java.io.File dir, java.lang.String dataDir) Checks whether Cassandra has RWX permissions to the specified directory.

Methods inherited from class java.lang.Object

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

Field Detail

BACKUPS_SUBDIR

public static final java.lang.String BACKUPS_SUBDIR

See Also:

Constant Field Values

SNAPSHOT_SUBDIR

public static final java.lang.String SNAPSHOT_SUBDIR

See Also:

Constant Field Values

SECONDARY_INDEX_NAME_SEPARATOR

public static final java.lang.String SECONDARY_INDEX_NAME_SEPARATOR

See Also:

Constant Field Values

dataDirectories

public static final Directories.DataDirectory[] dataDirectories

Constructor Detail

Directories

public Directories(CFMetaData metadata)

Create Directories of given ColumnFamily. SSTable directories are created under data_directories defined in cassandra.yaml if not exist at this time.

Parameters:

metadata - metadata of ColumnFamily

Method Detail

verifyFullPermissions

public static boolean verifyFullPermissions(java.io.File dir,
                                            java.lang.String dataDir)

Checks whether Cassandra has RWX permissions to the specified directory. Logs an error with the details if it does not.

Parameters:

dir - File object of the directory.

dataDir - String representation of the directory's location

Returns:

status representing Cassandra's RWX permissions to the supplied folder location.

getLocationForDisk

public java.io.File getLocationForDisk(Directories.DataDirectory dataDirectory)

Returns SSTable location which is inside given data directory.

Parameters:

dataDirectory -

Returns:

SSTable location

find

public Descriptor find(java.lang.String filename)

getDirectoryForNewSSTables

public java.io.File getDirectoryForNewSSTables()

Basically the same as calling getWriteableLocationAsFile(long) with an unknown size (-1L), which may return any non-blacklisted directory - even a data directory that has no usable space. Do not use this method in production code.

Throws:

java.io.IOError - if all directories are blacklisted.

getWriteableLocationAsFile

public java.io.File getWriteableLocationAsFile(long writeSize)

Returns a non-blacklisted data directory that _currently_ has writeSize bytes as usable space.

Throws:

java.io.IOError - if all directories are blacklisted.

getWriteableLocation

public Directories.DataDirectory getWriteableLocation(long writeSize)

Returns a non-blacklisted data directory that _currently_ has writeSize bytes as usable space.

Throws:

java.io.IOError - if all directories are blacklisted.

hasAvailableDiskSpace

public boolean hasAvailableDiskSpace(long estimatedSSTables,
                                     long expectedTotalWriteSize)

getSnapshotDirectory

public static java.io.File getSnapshotDirectory(Descriptor desc,
                                                java.lang.String snapshotName)

getSnapshotDirectory

public static java.io.File getSnapshotDirectory(java.io.File location,
                                                java.lang.String snapshotName)

getSnapshotManifestFile

public java.io.File getSnapshotManifestFile(java.lang.String snapshotName)

getBackupsDirectory

public static java.io.File getBackupsDirectory(Descriptor desc)

getBackupsDirectory

public static java.io.File getBackupsDirectory(java.io.File location)

sstableLister

public Directories.SSTableLister sstableLister()

getSnapshotDetails

public java.util.Map<java.lang.String,Pair<java.lang.Long,java.lang.Long>> getSnapshotDetails()

Returns:

Return a map of all snapshots to space being used The pair for a snapshot has size on disk and true size.

snapshotExists

public boolean snapshotExists(java.lang.String snapshotName)

clearSnapshot

public static void clearSnapshot(java.lang.String snapshotName,
                                 java.util.List<java.io.File> snapshotDirectories)

snapshotCreationTime

public long snapshotCreationTime(java.lang.String snapshotName)

trueSnapshotsSize

public long trueSnapshotsSize()

getTrueAllocatedSizeIn

public long getTrueAllocatedSizeIn(java.io.File input)

getKSChildDirectories

public static java.util.List<java.io.File> getKSChildDirectories(java.lang.String ksName)

getCFDirectories

public java.util.List<java.io.File> getCFDirectories()