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  1. Cassandra
  2. CASSANDRA-5679

Wide Row calls map method once per column in Hadoop MapReduce

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    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Normal
    • Resolution: Won't Fix
    • Fix Version/s: None
    • Component/s: None
    • Labels:
    • Environment:

      CentOS 6.3, Hadoop 1.1.2, Cassandra 1.2.4

    • Severity:
      Normal

      Description

      When using Cassandra without wide row support in a Hadoop job, the map method gets a number of columns limited by the SlicePredicate every time the map method in the mapper is called; but when using wide row support, the map method is called once for every column. It seems like the limit in SlicePredicate is ignored when wide row set to true.

      This prevents in-map reducing code to work (i.e. emit top ten from a mapper).

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              • Assignee:
                Unassigned
                Reporter:
                touchdown Tony Zhao
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                • Created:
                  Updated:
                  Resolved: