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  1. Core Server
  2. SERVER-16908

Performance Regression in Foreground Index Builds with MMAPv1

    • Type: Icon: Bug Bug
    • Resolution: Done
    • Priority: Icon: Critical - P2 Critical - P2
    • 3.0.0-rc6
    • Affects Version/s: 2.8.0-rc5
    • Component/s: Index Maintenance
    • None
    • Fully Compatible
    • ALL
    • Hide

      Run the attached script, but modify the list of hosts at the bottom to reflect the workload target hosts (localhost:27107 is the first host by default).

      The script reports the amount of time (in milliseconds) each index build takes, as well as the initial insert phase.

      Show
      Run the attached script, but modify the list of hosts at the bottom to reflect the workload target hosts (localhost:27107 is the first host by default). The script reports the amount of time (in milliseconds) each index build takes, as well as the initial insert phase.

      In v2.8-rc5 with mmapv1, foreground index builds are ~10-30% slower than v2.6.6. Wired Tiger is ~5% - 30% faster than v2.6.6.

      Results:

      {
        insert_500000_docs: 238229ms,
        build_fg_ascending: 1715ms,
        build_fg_descending: 1838ms,
        build_fg_random: 3162ms,
        build_fg_unique: 1979ms,
        build_fg_sparse: 2228ms,
        build_fg_multikey: 10051ms,
        build_fg_string: 4205ms,
        build_fg_text: 25846ms,
        build_fg_hash: 2259ms,
        version: 2.6.6,
        storage_engine: mmapv1
      },
      {
        insert_500000_docs: 268692ms,
        build_fg_ascending: 2944ms,
        build_fg_descending: 2463ms,
        build_fg_random: 3369ms,
        build_fg_unique: 2591ms,
        build_fg_sparse: 2820ms,
        build_fg_multikey: 10759ms,
        build_fg_string: 3947ms,
        build_fg_text: 24254ms,
        build_fg_hash: 2511ms,
        version: 2.8.0-rc2,
        storage_engine: mmapv1
      },
      {
        insert_500000_docs: 271507ms,
        build_fg_ascending: 2569ms,
        build_fg_descending: 2552ms,
        build_fg_random: 3370ms,
        build_fg_unique: 2658ms,
        build_fg_sparse: 2803ms,
        build_fg_multikey: 11021ms,
        build_fg_string: 3989ms,
        build_fg_text: 25493ms,
        build_fg_hash: 2603ms,
        version: 2.8.0-rc4,
        storage_engine: mmapv1
      },
      {
        insert_500000_docs: 268413ms,
        build_fg_ascending: 2303ms,
        build_fg_descending: 2327ms,
        build_fg_random: 3274ms,
        build_fg_unique: 2499ms,
        build_fg_sparse: 2661ms,
        build_fg_multikey: 10371ms,
        build_fg_string: 3727ms,
        build_fg_text: 23728ms,
        build_fg_hash: 2394ms,
        version: 2.8.0-rc5,
        storage_engine: mmapv1
      },
      {
      Cannot use commands write mode, degrading to compatibility mode
        insert_500000_docs: 288943ms,
        build_fg_ascending: 1960ms,
        build_fg_descending: 1981ms,
        build_fg_random: 2972ms,
        build_fg_unique: 2044ms,
        build_fg_sparse: 2303ms,
        build_fg_multikey: 11945ms,
        build_fg_string: 3345ms,
        build_fg_text: 221ms,
        build_fg_hash: 2202ms,
        version: 2.4.9,
        storage_engine: mmapv1
      },
      {
        insert_500000_docs: 254796ms,
        build_fg_ascending: 1772ms,
        build_fg_descending: 1610ms,
        build_fg_random: 2566ms,
        build_fg_unique: 1802ms,
        build_fg_sparse: 2022ms,
        build_fg_multikey: 8351ms,
        build_fg_string: 3122ms,
        build_fg_text: 20574ms,
        build_fg_hash: 1776ms,
        version: 2.8.0-rc5,
        storage_engine: wiredTiger
      }
      

            Assignee:
            milkie@mongodb.com Eric Milkie
            Reporter:
            benjamin.becker Ben Becker
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            Watchers:
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              Created:
              Updated:
              Resolved: