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  1. Core Server
  2. SERVER-17622

Total storage size for Journal substantially different for WT and MMAPv1

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Works as Designed
    • Affects Version/s: 3.0.0
    • Fix Version/s: None
    • Component/s: MMAPv1, Storage, WiredTiger
    • Labels:
    • Backwards Compatibility:
      Fully Compatible
    • Operating System:
      ALL
    • Steps To Reproduce:
      Hide

      /home/alvin/mongodb-linux-x86_64-3.0.1/bin/mongod --dbpath /data-nfs/db --logpath /data3/logs/db/sysbench/server.log --fork --syncdelay 14400 --storageEngine=mmapv1 --bind_ip 127.0.0.1

      sh /home/alvin/alvin-sysbench-new/run.simple.bash 16

      Show
      /home/alvin/mongodb-linux-x86_64-3.0.1/bin/mongod --dbpath /data-nfs/db --logpath /data3/logs/db/sysbench/server.log --fork --syncdelay 14400 --storageEngine=mmapv1 --bind_ip 127.0.0.1 sh /home/alvin/alvin-sysbench-new/run.simple.bash 16

      Description

      Problem

      Using sysbench to load 16M documents (in 16 collections) and then execute a 10 minute workload results in very different storage usage. WiredTiger uses 5GB, MMAPv1 20GB. The substantial difference is in the journal directory 1.8 GB(WT) versus 16GB (MMAPv1).

      wiredTiger

       
      alvin@bismark:/data-nfs/db$ du -sh
      5.0G	.
       
      16K	collection-0--6859785001528658125.wt
      186M	collection-11--6859785001528658125.wt
      186M	collection-14--6859785001528658125.wt
      186M	collection-17--6859785001528658125.wt
      186M	collection-20--6859785001528658125.wt
      186M	collection-23--6859785001528658125.wt
      186M	collection-26--6859785001528658125.wt
      186M	collection-2--6859785001528658125.wt
      186M	collection-29--6859785001528658125.wt
      186M	collection-32--6859785001528658125.wt
      186M	collection-35--6859785001528658125.wt
      186M	collection-38--6859785001528658125.wt
      186M	collection-41--6859785001528658125.wt
      186M	collection-44--6859785001528658125.wt
      186M	collection-47--6859785001528658125.wt
      186M	collection-5--6859785001528658125.wt
      186M	collection-8--6859785001528658125.wt
      9.0M	index-10--6859785001528658125.wt
      9.8M	index-12--6859785001528658125.wt
      8.9M	index-13--6859785001528658125.wt
      9.8M	index-15--6859785001528658125.wt
      8.8M	index-16--6859785001528658125.wt
      16K	index-1--6859785001528658125.wt
      9.8M	index-18--6859785001528658125.wt
      9.0M	index-19--6859785001528658125.wt
      9.8M	index-21--6859785001528658125.wt
      9.0M	index-22--6859785001528658125.wt
      9.8M	index-24--6859785001528658125.wt
      9.0M	index-25--6859785001528658125.wt
      9.8M	index-27--6859785001528658125.wt
      9.1M	index-28--6859785001528658125.wt
      9.8M	index-30--6859785001528658125.wt
      9.1M	index-31--6859785001528658125.wt
      9.8M	index-33--6859785001528658125.wt
      9.1M	index-34--6859785001528658125.wt
      9.8M	index-36--6859785001528658125.wt
      9.8M	index-3--6859785001528658125.wt
      9.1M	index-37--6859785001528658125.wt
      9.8M	index-39--6859785001528658125.wt
      9.0M	index-40--6859785001528658125.wt
      9.8M	index-42--6859785001528658125.wt
      9.1M	index-43--6859785001528658125.wt
      9.8M	index-45--6859785001528658125.wt
      9.1M	index-46--6859785001528658125.wt
      8.9M	index-4--6859785001528658125.wt
      9.8M	index-48--6859785001528658125.wt
      9.1M	index-49--6859785001528658125.wt
      9.8M	index-6--6859785001528658125.wt
      9.0M	index-7--6859785001528658125.wt
      9.8M	index-9--6859785001528658125.wt
      1.8G	journal
      16K	_mdb_catalog.wt
      0	mongod.lock
      32K	sizeStorer.wt
      4.0K	storage.bson
      12K	_tmp
      0	WiredTiger
      4.0K	WiredTiger.basecfg
      0	WiredTiger.lock
      4.0K	WiredTiger.turtle
      164K	WiredTiger.wt
      

      MMAPv1

      == MMAP
      alvin@bismark:/data-nfs/db$ du -sh
      20G     .
       
      alvin@bismark:/data-nfs/db$ du -sh *
      16G     journal
      52K     local.0
      17M     local.ns
      0       mongod.lock
      63M     sbtest.0
      121M    sbtest.1
      254M    sbtest.2
      502M    sbtest.3
      1003M   sbtest.4
      2.0G    sbtest.5
      898M    sbtest.6
      37M     sbtest.7
      17M     sbtest.ns
      4.0K    storage.bson
      4.0K    _tmp
      

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              • Created:
                Updated:
                Resolved: