Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 0.8.1
    • Component/s: None
    • Labels:
      None

      Description

      Right now on each machine, we create M * R temporary files for shuffle, where M = number of map tasks, R = number of reduce tasks.

      This can be pretty high when there are lots of mappers and reducers (e.g. 1k map * 1k reduce = 1 million files for a single shuffle). The high number can cripple the file system and significantly slow the system down.

      We should cut this number down to O(R) instead of O(M*R).

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            • Assignee:
              jason.dai Jason Dai
              Reporter:
              rxin Reynold Xin
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              • Created:
                Updated:
                Resolved: