org.apache.hadoop.hdfs

类 DistributedFileSystem

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.fs.FileSystem

org.apache.hadoop.hdfs.DistributedFileSystem

所有已实现的接口:

Closeable, AutoCloseable, Configurable

public class DistributedFileSystem
extends FileSystem

Implementation of the abstract FileSystem for the DFS system. This object is the way end-user code interacts with a Hadoop DistributedFileSystem.

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	DistributedFileSystem.DiskStatus

从类继承的嵌套类/接口 org.apache.hadoop.fs.FileSystem

FileSystem.Statistics

字段概要

从类继承的字段 org.apache.hadoop.fs.FileSystem

FS_DEFAULT_NAME_KEY, LOG, statistics

构造器概要

构造器

构造器和说明
DistributedFileSystem()
DistributedFileSystem(InetSocketAddress namenode, Configuration conf) 已过时。

方法概要

方法

限定符和类型	方法和说明
FSDataOutputStream	append(Path f, int bufferSize, Progressable progress) This optional operation is not yet supported.
void	cancelDelegationToken(Token<DelegationTokenIdentifier> token) 已过时。 Use Token.cancel instead.
void	close() No more filesystem operations are needed.
void	concat(Path trg, Path[] psrcs) Move blocks from srcs to trg and delete srcs afterwards.
FSDataOutputStream	create(Path f, FsPermission permission, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress) Opens an FSDataOutputStream at the indicated Path with write-progress reporting.
FSDataOutputStream	createNonRecursive(Path f, FsPermission permission, boolean overwrite, int bufferSize, short replication, long blockSize, Progressable progress) Same as create(), except fails if parent directory doesn't already exist.
boolean	delete(Path f) 已过时。
boolean	delete(Path f, boolean recursive) requires a boolean check to delete a non empty directory recursively.
UpgradeStatusReport	distributedUpgradeProgress(FSConstants.UpgradeAction action)
void	finalizeUpgrade() Finalize previously upgraded files system state.
DFSClient	getClient()
ContentSummary	getContentSummary(Path f) Return the ContentSummary of a given Path.
long	getCorruptBlocksCount() Returns count of blocks with at least one replica marked corrupt.
DatanodeInfo[]	getDataNodeStats() Return statistics for each datanode.
long	getDefaultBlockSize() Return the number of bytes that large input files should be optimally be split into to minimize i/o time.
protected int	getDefaultPort() Get the default port for this file system.
short	getDefaultReplication() Get the default replication.
Token<DelegationTokenIdentifier>	getDelegationToken(String renewer) Get a new delegation token for this file system.
Token<DelegationTokenIdentifier>	getDelegationToken(Text renewer) 已过时。
DistributedFileSystem.DiskStatus	getDiskStatus() Return the disk usage of the filesystem, including total capacity, used space, and remaining space
BlockLocation[]	getFileBlockLocations(FileStatus file, long start, long len) Return an array containing hostnames, offset and size of portions of the given file.
MD5MD5CRC32FileChecksum	getFileChecksum(Path f) Get the checksum of a file.
FileStatus	getFileStatus(Path f) Returns the stat information about the file.
Path	getHomeDirectory() Return the current user's home directory in this filesystem.
long	getMissingBlocksCount() Returns count of blocks with no good replicas left.
String	getName() 已过时。
long	getRawCapacity() Return the total raw capacity of the filesystem, disregarding replication .
long	getRawUsed() Return the total raw used space in the filesystem, disregarding replication .
long	getUnderReplicatedBlocksCount() Returns count of blocks with one of more replica missing.
URI	getUri() Returns a URI whose scheme and authority identify this FileSystem.
Path	getWorkingDirectory() Get the current working directory for the given file system
void	initialize(URI uri, Configuration conf) Called after a new FileSystem instance is constructed.
boolean	isFileClosed(Path src) Get the close status of a file
static boolean	isHealthy(URI uri) Is the HDFS healthy?
FileStatus[]	listStatus(Path p) List all the entries of a directory Note that this operation is not atomic for a large directory.
void	metaSave(String pathname)
boolean	mkdirs(Path f, FsPermission permission) Make the given file and all non-existent parents into directories.
FSDataInputStream	open(Path f, int bufferSize) Opens an FSDataInputStream at the indicated Path.
boolean	recoverLease(Path f) Start the lease recovery of a file
void	refreshNodes() Refreshes the list of hosts and excluded hosts from the configured files.
boolean	rename(Path src, Path dst) Rename files/dirs
long	renewDelegationToken(Token<DelegationTokenIdentifier> token) 已过时。 Use Token.renew instead.
boolean	reportChecksumFailure(Path f, FSDataInputStream in, long inPos, FSDataInputStream sums, long sumsPos) We need to find the blocks that didn't match.
void	saveNamespace() Save namespace image.
void	setBalancerBandwidth(long bandwidth) Requests the namenode to tell all datanodes to use a new, non-persistent bandwidth value for dfs.balance.bandwidthPerSec.
void	setOwner(Path p, String username, String groupname) Set owner of a path (i.e. a file or a directory).
void	setPermission(Path p, FsPermission permission) Set permission of a path.
void	setQuota(Path src, long namespaceQuota, long diskspaceQuota) Set a directory's quotas
boolean	setReplication(Path src, short replication) Set replication for an existing file.
boolean	setSafeMode(FSConstants.SafeModeAction action) Enter, leave or get safe mode.
void	setTimes(Path p, long mtime, long atime) Set access time of a file
void	setVerifyChecksum(boolean verifyChecksum) Set the verify checksum flag.
void	setWorkingDirectory(Path dir) Set the current working directory for the given file system.
String	toString()

从类继承的方法 org.apache.hadoop.fs.FileSystem

addFileSystemForTesting, append, append, checkPath, clearStatistics, closeAll, closeAllForUGI, completeLocalOutput, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyFromLocalFile, copyToLocalFile, copyToLocalFile, create, create, create, create, create, create, create, create, create, create, createNewFile, createNonRecursive, deleteOnExit, exists, get, get, get, getAllStatistics, getBlockSize, getCacheSize, getCanonicalServiceName, getCanonicalUri, getDefaultBlockSize, getDefaultReplication, getDefaultUri, getLength, getLocal, getNamed, getReplication, getStatistics, getStatistics, getUsed, globStatus, globStatus, isDirectory, isFile, listStatus, listStatus, listStatus, makeQualified, mkdirs, mkdirs, moveFromLocalFile, moveFromLocalFile, moveToLocalFile, open, printStatistics, processDeleteOnExit, setDefaultUri, setDefaultUri, startLocalOutput

从类继承的方法 org.apache.hadoop.conf.Configured

getConf, setConf

从类继承的方法 java.lang.Object

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

构造器详细资料

DistributedFileSystem

public DistributedFileSystem()

DistributedFileSystem

public DistributedFileSystem(InetSocketAddress namenode,
                     Configuration conf)
                      throws IOException

已过时。

抛出:

IOException

方法详细资料

getName

public String getName()

已过时。

覆盖:

getName 在类中 FileSystem

getUri

public URI getUri()

从类复制的说明: FileSystem

Returns a URI whose scheme and authority identify this FileSystem.

指定者:

getUri 在类中 FileSystem

initialize

public void initialize(URI uri,
              Configuration conf)
                throws IOException

从类复制的说明: FileSystem

Called after a new FileSystem instance is constructed.

覆盖:

initialize 在类中 FileSystem

参数:

uri - a uri whose authority section names the host, port, etc. for this FileSystem

conf - the configuration

抛出:

IOException

getWorkingDirectory

public Path getWorkingDirectory()

从类复制的说明: FileSystem

Get the current working directory for the given file system

指定者:

getWorkingDirectory 在类中 FileSystem

返回:

the directory pathname

getDefaultBlockSize

public long getDefaultBlockSize()

从类复制的说明: FileSystem

Return the number of bytes that large input files should be optimally be split into to minimize i/o time.

覆盖:

getDefaultBlockSize 在类中 FileSystem

getDefaultReplication

public short getDefaultReplication()

从类复制的说明: FileSystem

Get the default replication.

覆盖:

getDefaultReplication 在类中 FileSystem

setWorkingDirectory

public void setWorkingDirectory(Path dir)

从类复制的说明: FileSystem

Set the current working directory for the given file system. All relative paths will be resolved relative to it.

指定者:

setWorkingDirectory 在类中 FileSystem

getHomeDirectory

public Path getHomeDirectory()

Return the current user's home directory in this filesystem. The default implementation returns "/user/$USER/".

覆盖:

getHomeDirectory 在类中 FileSystem

getFileBlockLocations

public BlockLocation[] getFileBlockLocations(FileStatus file,
                                    long start,
                                    long len)
                                      throws IOException

从类复制的说明: FileSystem

Return an array containing hostnames, offset and size of portions of the given file. For a nonexistent file or regions, null will be returned. This call is most helpful with DFS, where it returns hostnames of machines that contain the given file. The FileSystem will simply return an elt containing 'localhost'.

覆盖:

getFileBlockLocations 在类中 FileSystem

抛出:

IOException

setVerifyChecksum

public void setVerifyChecksum(boolean verifyChecksum)

从类复制的说明: FileSystem

Set the verify checksum flag. This is only applicable if the corresponding FileSystem supports checksum. By default doesn't do anything.

覆盖:

setVerifyChecksum 在类中 FileSystem

open

public FSDataInputStream open(Path f,
                     int bufferSize)
                       throws IOException

从类复制的说明: FileSystem

Opens an FSDataInputStream at the indicated Path.

指定者:

open 在类中 FileSystem

参数:

f - the file name to open

bufferSize - the size of the buffer to be used.

抛出:

IOException

isFileClosed

public boolean isFileClosed(Path src)
                     throws IOException

Get the close status of a file

参数:

src - The path to the file

返回:

return true if file is closed

抛出:

FileNotFoundException - if the file does not exist.

IOException - If an I/O error occurred

recoverLease

public boolean recoverLease(Path f)
                     throws IOException

Start the lease recovery of a file

参数:

f - a file

返回:

true if the file is already closed

抛出:

IOException - if an error occurs

append

public FSDataOutputStream append(Path f,
                        int bufferSize,
                        Progressable progress)
                          throws IOException

This optional operation is not yet supported.

指定者:

append 在类中 FileSystem

参数:

f - the existing file to be appended.

bufferSize - the size of the buffer to be used.

progress - for reporting progress if it is not null.

抛出:

IOException

create

public FSDataOutputStream create(Path f,
                        FsPermission permission,
                        boolean overwrite,
                        int bufferSize,
                        short replication,
                        long blockSize,
                        Progressable progress)
                          throws IOException

从类复制的说明: FileSystem

Opens an FSDataOutputStream at the indicated Path with write-progress reporting.

指定者:

create 在类中 FileSystem

参数:

f - the file name to open

overwrite - if a file with this name already exists, then if true, the file will be overwritten, and if false an error will be thrown.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

抛出:

IOException

另请参阅:

FileSystem.setPermission(Path, FsPermission)

createNonRecursive

public FSDataOutputStream createNonRecursive(Path f,
                                    FsPermission permission,
                                    boolean overwrite,
                                    int bufferSize,
                                    short replication,
                                    long blockSize,
                                    Progressable progress)
                                      throws IOException

Same as create(), except fails if parent directory doesn't already exist.

覆盖:

createNonRecursive 在类中 FileSystem

参数:

f - the file name to open

overwrite - if a file with this name already exists, then if true, the file will be overwritten, and if false an error will be thrown.

bufferSize - the size of the buffer to be used.

replication - required block replication for the file.

抛出:

IOException

另请参阅:

create(Path, FsPermission, boolean, int, short, long, Progressable)

setReplication

public boolean setReplication(Path src,
                     short replication)
                       throws IOException

从类复制的说明: FileSystem

Set replication for an existing file.

覆盖:

setReplication 在类中 FileSystem

参数:

src - file name

replication - new replication

返回:

true if successful; false if file does not exist or is a directory

抛出:

IOException

concat

public void concat(Path trg,
          Path[] psrcs)
            throws IOException

Move blocks from srcs to trg and delete srcs afterwards. The file block sizes must be the same.

覆盖:

concat 在类中 FileSystem

参数:

trg - existing file to append to

psrcs - list of files (same block size, same replication)

抛出:

IOException

rename

public boolean rename(Path src,
             Path dst)
               throws IOException

Rename files/dirs

指定者:

rename 在类中 FileSystem

抛出:

IOException

delete

@Deprecated
public boolean delete(Path f)
               throws IOException

已过时。

Get rid of Path f, whether a true file or dir.

指定者:

delete 在类中 FileSystem

抛出:

IOException

delete

public boolean delete(Path f,
             boolean recursive)
               throws IOException

requires a boolean check to delete a non empty directory recursively.

指定者:

delete 在类中 FileSystem

参数:

f - the path to delete.

recursive - if path is a directory and set to true, the directory is deleted else throws an exception. In case of a file the recursive can be set to either true or false.

返回:

true if delete is successful else false.

抛出:

IOException

getContentSummary

public ContentSummary getContentSummary(Path f)
                                 throws IOException

Return the ContentSummary of a given Path.

覆盖:

getContentSummary 在类中 FileSystem

抛出:

IOException

setQuota

public void setQuota(Path src,
            long namespaceQuota,
            long diskspaceQuota)
              throws IOException

Set a directory's quotas

抛出:

IOException

另请参阅:

ClientProtocol.setQuota(String, long, long)

listStatus

public FileStatus[] listStatus(Path p)
                        throws IOException

List all the entries of a directory Note that this operation is not atomic for a large directory. The entries of a directory may be fetched from NameNode multiple times. It only guarantees that each name occurs once if a directory undergoes changes between the calls.

指定者:

listStatus 在类中 FileSystem

参数:

p - given path

返回:

the statuses of the files/directories in the given patch returns null, if Path f does not exist in the FileSystem

抛出:

IOException

mkdirs

public boolean mkdirs(Path f,
             FsPermission permission)
               throws IOException

从类复制的说明: FileSystem

Make the given file and all non-existent parents into directories. Has the semantics of Unix 'mkdir -p'. Existence of the directory hierarchy is not an error.

指定者:

mkdirs 在类中 FileSystem

抛出:

IOException

close

public void close()
           throws IOException

No more filesystem operations are needed. Will release any held locks.

指定者:

close 在接口中 Closeable

指定者:

close 在接口中 AutoCloseable

覆盖:

close 在类中 FileSystem

抛出:

IOException

toString

public String toString()

覆盖:

toString 在类中 Object

getClient

public DFSClient getClient()

getDiskStatus

public DistributedFileSystem.DiskStatus getDiskStatus()
                                               throws IOException

Return the disk usage of the filesystem, including total capacity, used space, and remaining space

抛出:

IOException

getRawCapacity

public long getRawCapacity()
                    throws IOException

Return the total raw capacity of the filesystem, disregarding replication .

抛出:

IOException

getRawUsed

public long getRawUsed()
                throws IOException

Return the total raw used space in the filesystem, disregarding replication .

抛出:

IOException

getMissingBlocksCount

public long getMissingBlocksCount()
                           throws IOException

Returns count of blocks with no good replicas left. Normally should be zero.

抛出:

IOException

getUnderReplicatedBlocksCount

public long getUnderReplicatedBlocksCount()
                                   throws IOException

Returns count of blocks with one of more replica missing.

抛出:

IOException

getCorruptBlocksCount

public long getCorruptBlocksCount()
                           throws IOException

Returns count of blocks with at least one replica marked corrupt.

抛出:

IOException

getDataNodeStats

public DatanodeInfo[] getDataNodeStats()
                                throws IOException

Return statistics for each datanode.

抛出:

IOException

setSafeMode

public boolean setSafeMode(FSConstants.SafeModeAction action)
                    throws IOException

Enter, leave or get safe mode.

抛出:

IOException

另请参阅:

ClientProtocol.setSafeMode( FSConstants.SafeModeAction)

saveNamespace

public void saveNamespace()
                   throws AccessControlException,
                          IOException

Save namespace image.

抛出:

AccessControlException

IOException

另请参阅:

ClientProtocol.saveNamespace()

refreshNodes

public void refreshNodes()
                  throws IOException

Refreshes the list of hosts and excluded hosts from the configured files.

抛出:

IOException

finalizeUpgrade

public void finalizeUpgrade()
                     throws IOException

Finalize previously upgraded files system state.

抛出:

IOException

distributedUpgradeProgress

public UpgradeStatusReport distributedUpgradeProgress(FSConstants.UpgradeAction action)
                                               throws IOException

抛出:

IOException

metaSave

public void metaSave(String pathname)
              throws IOException

抛出:

IOException

reportChecksumFailure

public boolean reportChecksumFailure(Path f,
                            FSDataInputStream in,
                            long inPos,
                            FSDataInputStream sums,
                            long sumsPos)

We need to find the blocks that didn't match. Likely only one is corrupt but we will report both to the namenode. In the future, we can consider figuring out exactly which block is corrupt.

getFileStatus

public FileStatus getFileStatus(Path f)
                         throws IOException

Returns the stat information about the file.

指定者:

getFileStatus 在类中 FileSystem

参数:

f - The path we want information from

返回:

a FileStatus object

抛出:

FileNotFoundException - if the file does not exist.

IOException

getFileChecksum

public MD5MD5CRC32FileChecksum getFileChecksum(Path f)
                                        throws IOException

Get the checksum of a file.

覆盖:

getFileChecksum 在类中 FileSystem

参数:

f - The file path

返回:

The file checksum. The default return value is null, which indicates that no checksum algorithm is implemented in the corresponding FileSystem.

抛出:

IOException

setPermission

public void setPermission(Path p,
                 FsPermission permission)
                   throws IOException

Set permission of a path.

覆盖:

setPermission 在类中 FileSystem

抛出:

IOException

setOwner

public void setOwner(Path p,
            String username,
            String groupname)
              throws IOException

Set owner of a path (i.e. a file or a directory). The parameters username and groupname cannot both be null.

覆盖:

setOwner 在类中 FileSystem

参数:

p - The path

username - If it is null, the original username remains unchanged.

groupname - If it is null, the original groupname remains unchanged.

抛出:

IOException

setTimes

public void setTimes(Path p,
            long mtime,
            long atime)
              throws IOException

Set access time of a file

覆盖:

setTimes 在类中 FileSystem

参数:

p - The path

mtime - Set the modification time of this file. The number of milliseconds since Jan 1, 1970. A value of -1 means that this call should not set modification time.

atime - Set the access time of this file. The number of milliseconds since Jan 1, 1970. A value of -1 means that this call should not set access time.

抛出:

IOException

getDefaultPort

protected int getDefaultPort()

从类复制的说明: FileSystem

Get the default port for this file system.

覆盖:

getDefaultPort 在类中 FileSystem

返回:

the default port or 0 if there isn't one

getDelegationToken

public Token<DelegationTokenIdentifier> getDelegationToken(String renewer)
                                                    throws IOException

从类复制的说明: FileSystem

Get a new delegation token for this file system.

覆盖:

getDelegationToken 在类中 FileSystem

参数:

renewer - the account name that is allowed to renew the token.

返回:

a new delegation token

抛出:

IOException

getDelegationToken

@Deprecated
public Token<DelegationTokenIdentifier> getDelegationToken(Text renewer)
                                                    throws IOException

已过时。

Get a valid Delegation Token.

参数:

renewer - Name of the designated renewer for the token

返回:

Token

抛出:

IOException

renewDelegationToken

public long renewDelegationToken(Token<DelegationTokenIdentifier> token)
                          throws SecretManager.InvalidToken,
                                 IOException

已过时。 Use Token.renew instead.

Renew an existing delegation token.

参数:

token - delegation token obtained earlier

返回:

the new expiration time

抛出:

IOException

SecretManager.InvalidToken

cancelDelegationToken

public void cancelDelegationToken(Token<DelegationTokenIdentifier> token)
                           throws IOException

已过时。 Use Token.cancel instead.

Cancel an existing delegation token.

参数:

token - delegation token

抛出:

IOException

setBalancerBandwidth

public void setBalancerBandwidth(long bandwidth)
                          throws IOException

Requests the namenode to tell all datanodes to use a new, non-persistent bandwidth value for dfs.balance.bandwidthPerSec. The bandwidth parameter is the max number of bytes per second of network bandwidth to be used by a datanode during balancing.

参数:

bandwidth - Blanacer bandwidth in bytes per second for all datanodes.

抛出:

IOException

isHealthy

public static boolean isHealthy(URI uri)

Is the HDFS healthy? HDFS is considered as healthy if it is up and not in safemode.

参数:

uri - the HDFS URI. Note that the URI path is ignored.

返回:

true if HDFS is healthy; false, otherwise.