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  1. WiredTiger
  2. WT-4336

With MongoDB, sweep attempts after table drops do not always close active dhandles

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Details

    • Bug
    • Status: Closed
    • Major - P3
    • Resolution: Done
    • 3.4.1, 3.6.1, 4.0.0
    • None
    • None
    • None
    • 5
    • Storage Engines 2018-10-08, Storage Engines 2018-10-22, Storage Engines 2018-11-05, Storage Engines 2018-11-19, Storage Engines 2018-12-03, Storage Engines 2018-12-17, Storage Engines 2018-12-31

    Description

      I ran this test on MongoDB 3.4.15 with the following config string:
      file_manager=(close_handle_minimum=1,close_idle_time=5,close_scan_interval=10)

      Test:

      1. I inserted a document each in two collections, hence creating these collections in the process
      2. I dropped these two collections

      Behaviour that needs investigation:
      Even though the sweep server is configured to sweep every 10 secs and close handles if there are any (close_handle_minimum=1), after several minutes the dhandle count has not reduced to what was before creating the collections.

      In the t2 data above:

      • 2 creates at A, 2 drops at B
      • Several minutes after the drops, after several data handle sweep attempts, active handles has NOT gone down.

      Attachments

        1. 3.4.15_drop_behavior.png
          3.4.15_drop_behavior.png
          131 kB
        2. 4.0.3.png
          4.0.3.png
          74 kB
        3. 403_handles_stuck.png
          403_handles_stuck.png
          173 kB
        4. handles_longrun_403.png
          handles_longrun_403.png
          22 kB
        5. r3.6.9.png
          r3.6.9.png
          63 kB
        6. run_me.sh
          4 kB
        7. testscript_403.py
          3 kB

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              sulabh.mahajan@mongodb.com Sulabh Mahajan
              sulabh.mahajan@mongodb.com Sulabh Mahajan
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              Dates

                Created:
                Updated:
                Resolved: