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  1. WiredTiger
  2. WT-7028

Sweep thread shouldn't lock during checkpoint gathering handles

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    Details

    • Type: Improvement
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: WT10.0.0, 4.9.0, 4.2.13, 4.4.5, 4.0.24
    • Component/s: None
    • Labels:
      None
    • Case:
    • Story Points:
      8
    • Backport Requested:
      v4.4, v4.2, v4.0

      Description

      In WT-5479, when sweep is running frequently and closing handles it needs to acquire the dhandle lock for writing. When checkpoint is running in the gathering handles phase it holds the schema lock and needs to hold the dhandle lock for reading. Sweep can interfere with that checkpoint operation resulting in holding the schema lock longer. Since sweep is a background non-time critical operation, we should avoid grabbing that lock for writing if gathering handles is in progress.

        Attachments

        1. 7028.diff
          2 kB
          Susan LoVerso
        2. 7028.wtperf
          0.6 kB
          Susan LoVerso
        3. Capture d’écran 2021-01-20 à 10.31.30.png
          181 kB
          Adrien Jarthon
        4. checkpoint_config_next.png
          219 kB
          Veli-Matti Lintu
        5. image (5).png
          69 kB
          Adrien Jarthon
        6. lock_dirty.png
          298 kB
          Veli-Matti Lintu
        7. perf-kernel-no-sweeper.svg
          2.99 MB
          Adrien Jarthon
        8. perf-kernel-sweeper.svg
          2.42 MB
          Adrien Jarthon
        9. screenshot-4.png
          222 kB
          Susan LoVerso
        10. screenshot-5.png
          73 kB
          Adrien Jarthon
        11. screenshot-6.png
          79 kB
          Adrien Jarthon
        12. Screenshot from 2021-01-07 17-58-37.png
          265 kB
          Adrien Jarthon
        13. Screenshot from 2021-01-07 17-59-10.png
          243 kB
          Adrien Jarthon
        14. sweeper_disabled.png
          250 kB
          Veli-Matti Lintu
        15. sweeper_enabled.png
          268 kB
          Veli-Matti Lintu

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              Assignee:
              sue.loverso Susan LoVerso
              Reporter:
              sue.loverso Susan LoVerso
              Votes:
              3 Vote for this issue
              Watchers:
              22 Start watching this issue

                Dates

                Created:
                Updated:
                Resolved: