Apache Hadoop 0.22.1 Release Notes

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


When configuring proxy users and hosts, the special wildcard value “*” may be specified to match any host or any user.


Adding support for Kerberos HTTP SPNEGO authentication to the Hadoop web-consoles


  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.

Submitting the patch after setting the user name at the client side


WARNING: No release note provided for this change.