[HADOOP-2027] FileSystem should provide byte ranges for file locations

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.17.0
• Component/s: fs
• Hadoop Flags: Incompatible change
• Release Note: New FileSystem API getFileBlockLocations to return the number of bytes in each block in a file via a single rpc to the namenode to speed up job planning. Deprecates getFileCacheHints.
• Assignee: Lohit Vijaya Renu
• Reporter: Owen O'Malley
• Created: 10/Oct/07 22:02
• Updated: 21/May/08 20:05
• Resolved: 19/Mar/08 23:56

Description

FileSystem's getFileCacheHints should be replaced with something more useful. I'd suggest replacing getFileCacheHints with a new method:

BlockLocation[] getFileLocations(Path file, long offset, long range) throws IOException;

and adding

class BlockLocation implements Writable {
  String[] getHosts();
  long getOffset();
  long getLength();
}

Issue Links

• relates to: HADOOP-3265 Remove deprecated API getFileCacheHints
• relates to: HADOOP-1296 Improve interface to FileSystem.getFileCacheHints