You are viewing a plain text version of this content. The canonical link for it is here.

Posted to mapreduce-dev@hadoop.apache.org by "Evert Lammerts (JIRA)" <ji...@apache.org> on 2011/07/01 10:30:29 UTC

[jira] [Created] (MAPREDUCE-2636) Scheduling over disks horizontally

Scheduling over disks horizontally
----------------------------------

                 Key: MAPREDUCE-2636
                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-2636
             Project: Hadoop Map/Reduce
          Issue Type: Improvement
          Components: job submission
            Reporter: Evert Lammerts
            Priority: Minor


Based on this message: http://mail-archives.apache.org/mod_mbox/hadoop-hdfs-user/201106.mbox/browser

The JT schedules tasks on nodes based on metadata it gets from the NN. The namenode does not know on which disk a block resides. It might happen that on a node running 4 tasks, all read from the same disk. This can affect performance.

An optimization might be to schedule horizontally over disks instead of nodes. Any ideas?

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira