Hadoop Map/Reduce
  1. Hadoop Map/Reduce
  2. MAPREDUCE-240

Improve the shuffle phase by using the "connection: keep-alive" and doing batch transfers of files

    Details

    • Type: Improvement Improvement
    • Status: Resolved
    • Priority: Major Major
    • Resolution: Duplicate
    • Affects Version/s: None
    • Fix Version/s: None
    • Component/s: None
    • Labels:
      None

      Description

      We should do transfers of map outputs at the granularity of total-bytes-transferred rather than the current way of transferring a single file and then closing the connection to the server. A single TaskTracker might have a couple of map output files for a given reduce, and we should transfer multiple of them (upto a certain total size) in a single connection to the TaskTracker. Using HTTP-1.1's keep-alive connection would help since it would keep the connection open for more than one file transfer. We should limit the transfers to a certain size so that we don't hold up a jetty thread indefinitely (and cause timeouts for other clients).
      Overall, this should give us improved performance.

      1. hadoop-1338-v1.patch
        58 kB
        Jothi Padmanabhan
      2. hadoop-1338-v2.patch
        65 kB
        Jothi Padmanabhan

        Issue Links

          Activity

            People

            • Assignee:
              Jothi Padmanabhan
              Reporter:
              Devaraj Das
            • Votes:
              0 Vote for this issue
              Watchers:
              13 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved:

                Development