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  1. Nutch
  2. NUTCH-1366

speed up indexing by eliminating the indexreducer

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    Details

    • Type: Improvement
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: nutchgora
    • Component/s: indexer
    • Labels:
      None
    • Patch Info:
      Patch Available

      Description

      Currently the indexer in Nutchgora consists of both mappers and reduces. But the reduce code does not actually iterate over any (grouped/sorted) values. It simply indexes individual key/value (String/Webpage) pairs. Therefore by moving this indexing code to the mapper we can eliminate the reduce step therefore making the indexing job much faster. (No more unnecessary spilling to disk/network and no cpu wasted to sorting).

      Note this is not (directly) applicable to trunk because trunk uses a quite different approach. Different types of input are combined to a single value in the reducer. Although I think it is possible to implement a similar optimization I am not sure how to do this. So if anyone wants this for trunk too feel free to implement a similar patch.

        Attachments

        1. NUTCH-1366.patch
          9 kB
          Ferdy

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            • Assignee:
              Unassigned
              Reporter:
              ferdy.g Ferdy
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              • Created:
                Updated:
                Resolved: