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  1. Core Server
  2. SERVER-47866

Secondary readers do not need to reacquire PBWM lock if there are catalog conflicts

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Details

    • Improvement
    • Status: Closed
    • Major - P3
    • Resolution: Fixed
    • None
    • 4.8.0
    • None
    • None
    • Fully Compatible
    • Execution Team 2020-09-21, Execution Team 2020-10-05
    • 23

    Description

      When a read on a secondary uses kLastApplied/kNoOverlap and encounters a collection catalog conflict, it uses a trick to reacquire the PBWM lock and read without a timestamp.

      This was necessary because single-phase background index builds would timestamp writes at future timestamps that may never be seen on secondaries (i.e. "ghost timestamps"). This is not necessary now that simultaneous index builds are the only index builds in 4.5+.

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              louis.williams@mongodb.com Louis Williams
              louis.williams@mongodb.com Louis Williams
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                Updated:
                Resolved: