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  1. Documentation
  2. DOCS-3286

Map/reduce documentation is wrong about write lock

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: v1.3.5
    • Component/s: manual
    • Labels:
      None
    • # Replies:
      2
    • Last comment by Customer:
      true
    • Actual Time:
      4

      Description

      The page on concurrency in map/reduce (http://docs.mongodb.org/manual/core/map-reduce-concurrency/) should make it clear that the write lock taken during the reduce phase is actually a global lock, rather than just a database-level lock. Also, while in non-atomic mode the lock is released and re-acquired for every single document that is written, the lock is pre-emptive in that case and thus has essentially the same effect as in atomic mode, rendering the server inaccessible for any other operation.

      (Compare SERVER-13552 where this issue is tracked.)

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                Dates

                • Created:
                  Updated:
                  Resolved:
                  Days since reply:
                  5 years, 49 weeks, 1 day ago
                  Date of 1st Reply: