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  1. WiredTiger
  2. WT-6490

Acquire snapshot for eviction threads

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Details

    • Improvement
    • Status: Closed
    • Major - P3
    • Resolution: Fixed
    • None
    • WT10.0.0, 4.4.2, 4.9.0
    • None
    • None
    • 5
    • Storage - Ra 2020-09-07, Storage - Ra 2020-09-21, Storage - Ra 2020-10-19

    Description

      At the moment eviction threads use checks based on global visibility rules - which means that they don't evict anything that isn't globally visible (based on transaction ID checks, not timestamp checks).

      We should update eviction so that it can evict anything that is committed or prepared. A possible way to do that is to allocate a transaction snapshot when doing evictions, but that requires care because application threads might be doing the eviction and we need to be careful not to use or disrupt their snapshot.

      See WT-6444 for more context and a workload where this change is beneficial.

      Attachments

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        2. a-2.png
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        3. a-3.png
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        4. eviction.patch
          77 kB
        5. FTDC_base.zip
          1.67 MB
        6. FTDC_eviction_improvement.zip
          1.81 MB
        7. image-2020-08-20-10-22-34-887.png
          image-2020-08-20-10-22-34-887.png
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        8. image-2020-08-20-10-38-59-705.png
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        9. image-2020-08-20-10-49-07-353.png
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        10. Screen Shot 2020-08-18 at 4.32.35 pm.png
          Screen Shot 2020-08-18 at 4.32.35 pm.png
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        11. Screen Shot 2020-08-18 at 4.33.54 pm.png
          Screen Shot 2020-08-18 at 4.33.54 pm.png
          879 kB

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              haseeb.bokhari@mongodb.com Haseeb Bokhari (Inactive)
              alexander.gorrod@mongodb.com Alexander Gorrod
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              Dates

                Created:
                Updated:
                Resolved: