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  1. Core Server
  2. SERVER-899

mapReduce fails on large sharded collection

    • Type: Icon: Bug Bug
    • Resolution: Done
    • Priority: Icon: Critical - P2 Critical - P2
    • 1.3.5
    • Affects Version/s: None
    • Component/s: Sharding
    • Labels:
      None
    • Environment:
      mongos built from git clone on 2010/1/7
      $ uname -a
      Linux toolbox 2.6.18-53.el5 #1 SMP Mon Nov 12 02:22:48 EST 2007 i686 i686 i386 GNU/Linux

      The following mapReduce runs successfully on a smaller collection in the same sharded db or on the same collection but on a non-sharded DB.

      --------------------------------------------------------------------------------

      > $mapv = function ()

      { emit(this.v, 1); }

      function () {
      emit(this.v, 1);
      }
      > $reducev = function ($vis_id, $counts) { var $count = 0; $counts.forEach(function ($c) {$count += $c;}); return $count; }
      function ($vis_id, $counts) {
      var $count = 0;
      $counts.forEach(function ($c) {$count += $c;});
      return $count;
      }
      > $resv = db.vis1.mapReduce( $mapv, $reducev, { query :

      { p : '78053631' }

      } );
      Fri Jan 8 12:54:08 JS Error: uncaught exception: map reduce failed: final reduce failed:

      { result: "tmp.mr.mapreduce_1262973236_124", errmsg: "assertion: assertion db/jsobj.h:1584", ok: 0.0 }

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            Assignee:
            mathias@mongodb.com Mathias Stearn
            Reporter:
            bennymack Ben B.
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              Created:
              Updated:
              Resolved: