Package org.apache.hadoop.hdfs

A distributed implementation of FileSystem.

See:
          Description

Class Summary
BlockReader This is a wrapper around connection to datadone and understands checksum, offset etc
DeprecatedUTF8 A simple wrapper around UTF8.
DFSClient DFSClient can connect to a Hadoop Filesystem and perform basic file tasks.
DFSClient.DFSDataInputStream The Hdfs implementation of FSDataInputStream
DFSConfigKeys This class contains constants for configuration keys used in hdfs.
DFSUtil  
DFSUtil.ErrorSimulator Utility class to facilitate junit test error simulation.
DistributedFileSystem Implementation of the abstract FileSystem for the DFS system.
DistributedFileSystem.DiskStatus Deprecated. Use FsStatus instead
HdfsConfiguration Adds deprecated keys into the configuration.
HDFSPolicyProvider PolicyProvider for HDFS protocols.
HftpFileSystem An implementation of a protocol for accessing filesystems over HTTP.
HsftpFileSystem An implementation of a protocol for accessing filesystems over HTTPS.
HsftpFileSystem.DummyHostnameVerifier Dummy hostname verifier that is used to bypass hostname checking
HsftpFileSystem.DummyTrustManager Dummy trustmanager that is used to trust all server certificates
 

Exception Summary
BlockMissingException This exception is thrown when a read encounters a block that has no locations associated with it.
 

Package org.apache.hadoop.hdfs Description

A distributed implementation of FileSystem. This is loosely modelled after Google's GFS.

The most important difference is that unlike GFS, Hadoop DFS files have strictly one writer at any one time. Bytes are always appended to the end of the writer's stream. There is no notion of "record appends" or "mutations" that are then checked or reordered. Writers simply emit a byte stream. That byte stream is guaranteed to be stored in the order written.



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