Faster directory traversal for raid node ----------------------------------------
Key: MAPREDUCE-2167 URL: https://issues.apache.org/jira/browse/MAPREDUCE-2167 Project: Hadoop Map/Reduce Issue Type: Improvement Components: contrib/raid Reporter: Ramkumar Vadali Assignee: Ramkumar Vadali The RaidNode currently iterates over the directory structure to figure out which files to RAID. With millions of files, this can take a long time - especially if some files are already RAIDed and the RaidNode needs to look at parity files / parity file HARs to determine if the file needs to be RAIDed. The directory traversal is encapsulated inside the class DirectoryTraversal, which examines one file at a time, using the caller's thread. My proposal is to make this multi-threaded as follows: * use a pool of threads inside DirectoryTraversal * The caller's thread is used to retrieve directories, and each new directory is assigned to a thread in the pool. The worker thread examines all the files the directory. * If there sub-directories, those are added back as workitems to the pool. Comments? -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.