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Posted to dev@nutch.apache.org by Apache Wiki <wi...@apache.org> on 2011/07/03 05:41:46 UTC

[Nutch Wiki] Trivial Update of "bin/nutch solrdedup" by LewisJohnMcgibbney

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The "bin/nutch solrdedup" page has been changed by LewisJohnMcgibbney:
http://wiki.apache.org/nutch/bin/nutch%20solrdedup?action=diff&rev1=1&rev2=2

  '''Preparation''':
  Query the solr server for the number of documents (say, N), Partition N among M map tasks. For example, if we have two map tasks the first map task will deal with solr documents from 0 - (N / 2 - 1) and the second will deal with documents from (N / 2) to (N - 1). This can be thought of as a linearly executing divide and conquer algorithm.
  
- '''MapReduce''':
+ '''Map Reduce''':
   * Map: Identity map where keys are digests and values are {@link SolrRecord} instances(which contain id, boost and timestamp)
  
   * Reduce: After map, {@link SolrRecord}s with the same digest will be grouped together. Now, of these documents with the same digests, delete all of them except the one with the highest score (boost field). If two (or more) documents have the same score, then the document with the latest timestamp is kept. Again, every other is deleted from solr index.