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  1. Core Server
  2. SERVER-45718

Index builder can skip index building for a non-empty collections due to incorrect fast count value.

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    • Type: Icon: Bug Bug
    • Resolution: Fixed
    • Priority: Icon: Major - P3 Major - P3
    • 4.3.4
    • Affects Version/s: None
    • Component/s: Storage
    • None
    • Fully Compatible
    • ALL
    • Execution Team 2020-01-27, Execution Team 2020-02-10
    • 86
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    • 3
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      Currently the fast count gets flushed to WT/disk only during following cases.
      1) fsync
      2) clean shutdown.
      3) During releasing WT session at an interval of 60 seconds (default) or 1000 ticks.
      4) During recovering to stable timestamp

      Basically, fast count is not tolerant to unclean shutdowns. So, if a node containing non-empty collections restarts after an unclean shutdown, there is  a possibility that that fast count returned after node restart can be 0 for that non-empty collection. As, a result, index build can skip index building thinking that's an empty collection.

            Assignee:
            suganthi.mani@mongodb.com Suganthi Mani
            Reporter:
            suganthi.mani@mongodb.com Suganthi Mani
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              Created:
              Updated:
              Resolved: