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

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

                Dates

                Created:
                Updated:
                Resolved: