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  1. Core Server
  2. SERVER-17342

20% drop in throughput on a contended document update between 2.6 and 3.0 MMAP

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    • Type: Icon: Bug Bug
    • Resolution: Duplicate
    • Priority: Icon: Critical - P2 Critical - P2
    • None
    • Affects Version/s: 3.0.0-rc9
    • Component/s: MMAPv1, Storage
    • ALL
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      /home/ec2-user/mongodb-linux-x86_64-2.6.7/bin/mongod --dbpath /data2/db --logpath /data3/logs/db/server.log --fork --bind_ip 127.0.0.1

      python benchrun.py -f testcases/complex_insert.js testcases/complex_update.js testcases/long_multi_update.js testcases/mixed_small.js testcases/simple_commands.js testcases/simple_geo_2d_index.js testcase
      s/simple_geo_2dsphere_index.js testcases/simple_insert.js testcases/simple_multi_update.js testcases/simple_query.js testcases/simple_remove.js testcases/simple_update.js testcases/simple_update_mms.js -t
      1 2 4 8 12 16 20 -l multiupdate-2.6.7-mmapv0-c1 --rhost 54.191.70.12 --rport 27017 -s /home/ec2-user/mongo-perf-shell/mongo --writeCmd true --trialCount 7 --trialTime 20 --testFilter \'MultiUpdate.v1.Con
      tended.Doc.Seq.Indexed\' -c 1 --dyno

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      /home/ec2-user/mongodb-linux-x86_64-2.6.7/bin/mongod --dbpath /data2/db --logpath /data3/logs/db/server.log --fork --bind_ip 127.0.0.1 python benchrun.py -f testcases/complex_insert.js testcases/complex_update.js testcases/long_multi_update.js testcases/mixed_small.js testcases/simple_commands.js testcases/simple_geo_2d_index.js testcase s/simple_geo_2dsphere_index.js testcases/simple_insert.js testcases/simple_multi_update.js testcases/simple_query.js testcases/simple_remove.js testcases/simple_update.js testcases/simple_update_mms.js -t 1 2 4 8 12 16 20 -l multiupdate-2.6.7-mmapv0-c1 --rhost 54.191.70.12 --rport 27017 -s /home/ec2-user/mongo-perf-shell/mongo --writeCmd true --trialCount 7 --trialTime 20 --testFilter \'MultiUpdate.v1.Con tended.Doc.Seq.Indexed\' -c 1 --dyno
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      Problem

      Observed 20% drop in throughput between 3.0.0-rc9 and 2.6.7 for MMAP storage engine. WT seems to have similar perf to 2.6.7.

      2.6.7 - 22907.37
      3.0.0-rc9 - 18285.02

      The results were gather from 20 second runs, each with 7 iterations. It can be seen there is very little variance in the attached screenshot from run-to-run.

      Testcase definition

      name: "MultiUpdate.v1.Contended.Doc.Seq.NoIndex"
pre: function( collection ) {
   collection.drop();
   for ( var i = 0; i < 4800; i++ ) {
      collection.insert( { _id : i , x : 0 } );
   }
   collection.getDB().getLastError();
   collection.ensureIndex( { x : 1 } );
   }
ops: { op:  "update",
     multi: true,
     query: { _id : 1600 },
     update: { $inc : { x : 1 } }
   },

        1. Screen Shot 2015-02-23 at 12.49.50 PM.png
          Screen Shot 2015-02-23 at 12.49.50 PM.png
          52 kB
        2. Screen Shot 2015-02-20 at 2.48.23 PM.png
          Screen Shot 2015-02-20 at 2.48.23 PM.png
          136 kB
        3. rc9.pdf
          21 kB
        4. multiupdate2-3.0.0-rc9-mmapv1-c1.tgz
          156 kB
        5. 267.pdf
          23 kB

            Assignee:
            david.storch@mongodb.com David Storch
            Reporter:
            alvin Alvin Richards (Inactive)
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            Watchers:
            13 Start watching this issue

              Created:
              Updated:
              Resolved: