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  1. WiredTiger
  2. WT-7028

Sweep thread shouldn't lock during checkpoint gathering handles

    • Type: Icon: Improvement Improvement
    • Resolution: Fixed
    • Priority: Icon: Major - P3 Major - P3
    • WT10.0.0, 4.9.0, 4.2.13, 4.4.5, 4.0.24
    • Affects Version/s: None
    • Component/s: None
    • None
    • 8
    • v4.4, v4.2, v4.0

      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.

        1. sweeper_enabled.png
          sweeper_enabled.png
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        2. sweeper_disabled.png
          sweeper_disabled.png
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        3. Screenshot from 2021-01-07 17-59-10.png
          Screenshot from 2021-01-07 17-59-10.png
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        4. Screenshot from 2021-01-07 17-58-37.png
          Screenshot from 2021-01-07 17-58-37.png
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        5. screenshot-6.png
          screenshot-6.png
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        6. screenshot-5.png
          screenshot-5.png
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        7. screenshot-4.png
          screenshot-4.png
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        8. perf-kernel-sweeper.svg
          2.42 MB
        9. perf-kernel-no-sweeper.svg
          2.99 MB
        10. lock_dirty.png
          lock_dirty.png
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        11. image (5).png
          image (5).png
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        12. checkpoint_config_next.png
          checkpoint_config_next.png
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        13. Capture d’écran 2021-01-20 à 10.31.30.png
          Capture d’écran 2021-01-20 à 10.31.30.png
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        14. 7028.wtperf
          0.6 kB
        15. 7028.diff
          2 kB

            Assignee:
            sue.loverso@mongodb.com Susan LoVerso
            Reporter:
            sue.loverso@mongodb.com Susan LoVerso
            Votes:
            3 Vote for this issue
            Watchers:
            23 Start watching this issue

              Created:
              Updated:
              Resolved: