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  1. Core Server
  2. SERVER-56520

Time-series inserts spent a lot of time in wt_calc_modify but don't generate deltas

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Details

    • Bug
    • Status: Closed
    • Major - P3
    • Resolution: Fixed
    • None
    • 5.0.0-rc2, 5.1.0-rc0
    • None
    • None
    • Fully Compatible
    • ALL
    • v5.0
    • Hide

      Run TSBS with cpu-only workload. Run db.point_data.stats() and look at the number of cursor modify operations. It doesn't increase during the work load, but attaching a profiles shows significant time spent in wiredtiger_calc_modify.

      Show
      Run TSBS with cpu-only workload. Run db.point_data.stats() and look at the number of cursor modify operations. It doesn't increase during the work load, but attaching a profiles shows significant time spent in wiredtiger_calc_modify .
    • Execution Team 2021-05-31, Execution Team 2021-06-14

    Description

      We spend 25% of time on attempting to compute WT_MODIFY deltas, but never succeed to the limit of 16 changes. We should either support deltas with more than 16 changes, or find a way to avoid useless calculations.

      Probably it is best to directly change the doc_diff updates into deltas.

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        Issue Links

          is related to

          Task - A task that needs to be done. SERVER-57101 Prove generating DamageVector from docDiff in unittest

          • Major - P3 - Major loss of function.
          • Closed
          related to

          Task - A task that needs to be done. SERVER-57159 Generate DamageVector from docDiff with subdocuments in unittest

          • Major - P3 - Major loss of function.
          • Closed

          Task - A task that needs to be done. SERVER-57504 Minimize the number of damages created for an internal time-series bucket collection update

          • Major - P3 - Major loss of function.
          • Closed

          Improvement - An improvement or enhancement to an existing feature or task. SERVER-57482 Adaptively call wiredtiger_calc_modify

          • Major - P3 - Major loss of function.
          • Backlog

          Activity

            People

              yuhong.zhang@mongodb.com Yuhong Zhang
              geert.bosch@mongodb.com Geert Bosch
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                Created:
                Updated:
                Resolved: