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  1. WiredTiger
  2. WT-6769

Investigate source of 40% regression in contended_update workload

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    Details

    • Type: Bug
    • Status: Open
    • Priority: Major - P3
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: Backlog
    • Component/s: None
    • Labels:
      None

      Description

      To investigate a perf BF, I ran two patch tests to compare between, the latest master and the latest master with 4.2 wiredtiger.

      Latest master:

      Latest master with 4.2 wiredtiger:

      We also saw that with 4.2 patch several test results dropped, which we do not see with the latest mongodb-4.2:

      Observations:

      • Moving from the latest wiredtiger in mongo/master to wiredtiger/mongodb-4.2 produced the same perf results for contended_update, but resulted in drop in perf for several other tests
      • At this point, we do not have a good explanation of what these results mean
      • It is not conclusive where the regression is coming from.

      Possibly we can isolate either a change in wiredtiger keeping the latest MongoDB, or a change in MongoDB keeping the latest WiredTiger. Alternatively, there is a complex list of changes involved and we can work to bring back the performance for contended_update back to 4.2 baseline.

      I have opened this ticket to address the next steps.

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        2. master-with-4.2.png
          master-with-4.2.png
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        3. results_drop.png
          results_drop.png
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          Activity

            People

            Assignee:
            backlog-server-storage-engines Backlog - Storage Engines Team
            Reporter:
            sulabh.mahajan Sulabh Mahajan
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              Dates

              Created:
              Updated: