Uploaded image for project: 'MongoDB Database Tools'
  1. MongoDB Database Tools
  2. TOOLS-1498

Stats collection has large playback performance impact

    • Type: Icon: Bug Bug
    • Resolution: Done
    • Priority: Icon: Major - P3 Major - P3
    • 3.4.1, 3.5.2
    • Affects Version/s: 3.4.0-rc0
    • Component/s: mongoreplay
    • Labels:
      None
    • Platforms 2016-11-21
    • v3.4

      FTDC timeseries data for both the recording and playback phases:

      • A-C: record phase
        • A-B: 8 threads each inserting 500 k empty documents into a single collection in batches of 1000
        • B-C: 1 thread doing a collection scan
      • D-G: playback phase
        • D-F: inserts - playback of A-B. Note how the rate of inserts drops about halfway through, by about a factor of 2, and the inserts don't end until F, overlapping the reads, unlike during the record phase
        • E-G: reads - playbck of B-C. Note that this appears to begin at about the right time corresponding to B during the recording, but unlike during the recording, on playback this begins before the inserts have ended.

        1. fixed.png
          92 kB
          Bruce Lucas
        2. longer.png
          63 kB
          Bruce Lucas
        3. varies.png
          111 kB
          Bruce Lucas

            Assignee:
            matt.cotter Matt Cotter
            Reporter:
            bruce.lucas@mongodb.com Bruce Lucas (Inactive)
            Votes:
            0 Vote for this issue
            Watchers:
            4 Start watching this issue

              Created:
              Updated:
              Resolved: