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  1. Documentation
  2. DOCS-7979

Size and count in collection stats are persisted during checkpoints in WiredTiger

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Details

    • Task
    • Status: Closed
    • Major - P3
    • Resolution: Fixed
    • None
    • 01112017-cleanup
    • manual
    • None

    Description

      https://docs.mongodb.com/manual/reference/command/collStats/#unexpected-shutdown-and-count

      I reported some inaccurate information via DOCS-5682, saying that size and count is updated every 1000 document writes. As clarified in SERVER-24266, we update the in-memory cache every 1000 document writes, but the updates only become persistent when WiredTigerKVEngine::syncSizeInfo is called, most commonly every 60 seconds as part of WiredTigerKVEngine::haveDropsQueued.

      This means that number can drift much more in the event of an unclean shutdown (as much as 60 seconds worth of writes).

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        Issue Links

          is related to

          Bug - A problem which impairs or prevents the functions of the product. SERVER-24266 Large discrepancy in SizeStorer after unclean shutdown

          • Major - P3 - Major loss of function.
          • Backlog

          Improvement - An improvement or enhancement to an existing feature or task. DOCS-5682 Document that the size and count in collection stats is not guaranteed to be 100% accurate

          • Major - P3 - Major loss of function.
          • Closed
          related to

          Task - A task that needs to be done. DOCS-8478 Size and Count Accuracy after Unexpected Shutdown in WT

          • Major - P3 - Major loss of function.
          • Closed

          Activity

            People

              ravind.kumar Ravind Kumar (Inactive)
              dan@mongodb.com Daniel Pasette (Inactive)
              Jess Mokrzecki Jess Mokrzecki
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              Dates

                Created:
                Updated:
                Resolved:
                6 years, 40 weeks, 4 days ago