Package org.apache.hadoop.dfs

A distributed implementation of FileSystem.

See:
          Description

Class Summary
DataNode DataNode is a class (and program) that stores a set of blocks for a DFS deployment.
DataNodeReport A report on the status of a DataNode.
DFSck This class provides rudimentary checking of DFS volumes for errors and sub-optimal conditions.
DFSck.Result Result of checking, plus overall DFS statistics.
DFSShell This class provides some DFS administrative access.
DistributedFileSystem Implementation of the abstract FileSystem for the DFS system.
NameNode NameNode serves as both directory namespace manager and "inode table" for the Hadoop DFS.
 

Package org.apache.hadoop.dfs 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.



Copyright © 2006 The Apache Software Foundation