Apache Hadoop 1.0.0 Release Notes

These release notes cover new developer and user-facing incompatibilities, important issues, features, and major improvements.

Docs version number is now automatically updated by reference to the build number.

Fixed security audit logger configuration. (Arpit Gupta via Eric Yang)

Enable task memory management to be configurable via hadoop config setup script.

Provide WebHDFS as a complete FileSystem implementation for accessing HDFS over HTTP. Previous hftp feature was a read-only FileSystem and does not provide “write” accesses.

  1. New configurations a. dfs.block.local-path-access.user is the key in datanode configuration to specify the user allowed to do short circuit read. b. dfs.client.read.shortcircuit is the key to enable short circuit read at the client side configuration. c. dfs.client.read.shortcircuit.skip.checksum is the key to bypass checksum check at the client side.
  2. By default none of the above are enabled and short circuit read will not kick in.
  3. If security is on, the feature can be used only for user that has kerberos credentials at the client, therefore map reduce tasks cannot benefit from it in general.

New DFSClient.create(…) allows option of not creating missing parent(s).