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  1. Apache Tez
  2. TEZ-2104

A CrossProductEdge which produces synthetic cross-product parallelism

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Details

    • New Feature
    • Status: Resolved
    • Major
    • Resolution: Fixed
    • None
    • 0.9.1
    • None

    Description

      Instead of producing duplicate data for the synthetic cross-product, to fit into partitions, the amount of net IO can be vastly reduced by a special purpose cross-product data movement edge.

      The Shuffle edge routes each partition's output to a single reducer, while the cross-product edge routes it into a matrix of reducers without actually duplicating the disk data.

      A partitioning scheme with 3 partitions on the lhs and rhs of a join operation can be routed into 9 reducers by performing a cross-product similar to

      (1,2,3) x (a,b,c) = [(1,a), (1,b), (1,c), (2,a), (2,b) ...]

      This turns a single task cross-product model into a distributed cross product.

      Attachments

        1. Cartesian product edge design.2.pdf
          284 kB
          Zhiyuan Yang
        2. Cross product edge design.pdf
          293 kB
          Zhiyuan Yang

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              zhiyuany Zhiyuan Yang
              gopalv Gopal Vijayaraghavan
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                Updated:
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