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From "Josh Wills (JIRA)" <>
Subject [jira] [Created] (CRUNCH-437) Fix Crunch Spark duplicate value aggregation
Date Sun, 06 Jul 2014 02:11:33 GMT
Josh Wills created CRUNCH-437:

             Summary: Fix Crunch Spark duplicate value aggregation
                 Key: CRUNCH-437
             Project: Crunch
          Issue Type: Bug
            Reporter: Josh Wills

The current Crunch-on-Spark mapside combiner uses a Multimap of key-value pairs to cache values
for local aggregation. This is awesome, except it means that identical key-value outputs before
a shuffle will only have one copy in the Multimap, which means that the aggregation counts
may not be correct. We should fix it to use a proper Map<K, List<V>> to ensure
that duplicate values are aggregated correctly.

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