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  1. WiredTiger
  2. WT-3089

Random update perf degradation in 2.9.0 vs 2.8.0

    • Type: Icon: Task Task
    • Resolution: Works as Designed
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: WT2.9.0
    • Component/s: None
    • None
    • Storage 2017-02-13

      Hi,
      In my synthetic test for comparing performance of random update from many threads in 2.8.0 and 2.9.0 I see that 2.8.0 shows better results than 2.9.0, 2.8.0:

      Threads count = 1, Total time = 408 usec
      Threads count = 2, Total time = 189 usec
      Threads count = 4, Total time = 113 usec
      Threads count = 8, Total time = 57 usec
      Threads count = 16, Total time = 91 usec
      Threads count = 24, Total time = 38 usec
      

      2.9.0:

      Threads count = 1, Total time = 1408 usec
      Threads count = 2, Total time = 968 usec
      Threads count = 4, Total time = 674 usec
      Threads count = 8, Total time = 452 usec
      Threads count = 16, Total time = 284 usec
      Threads count = 24, Total time = 261 usec
      

      Test attached to this case. Flamegraphs(attached too) show that it is related to behaviour of eviction thread. I can not reproduce this delay in our production environment, so looks like it is not problem for us, but is it expected behaviour? And if so, can you please say what has changed?

        1. 280.svg
          132 kB
          Denis Shkirya
        2. 290.svg
          157 kB
          Denis Shkirya
        3. update_rand_item.cpp
          5 kB
          Denis Shkirya

            Assignee:
            alexander.gorrod@mongodb.com Alexander Gorrod
            Reporter:
            Denis Shkirya Denis Shkirya
            Votes:
            1 Vote for this issue
            Watchers:
            8 Start watching this issue

              Created:
              Updated:
              Resolved: