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From "Cummins, Robert [USA]" <cummins_rob...@bah.com>
Subject order of values passed by mapreduce table classes
Date Tue, 22 Feb 2011 15:51:28 GMT


For the following is an enhancement or bug fix needed?


 When using map class:  TableMapper<ImmutableBytesWritable, IntWritable>

 with reduce class:  TableReducer<ImmutableBytesWritable, IntWritable, ImmutableBytesWritable>

the  order of Iterable<IntWritable> values passed to the reducer from the mapper is
not preserved in a small percentage of cases.

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

Suggestion:  Guaranteeing the chronological order of receipt by the reducer as per the order
written to the context by the mapper would give helpful and simple facility for identification
purposes to the reducer.



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