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  1. Core Server
  2. SERVER-22923

iowait increases slightly after upgrading from MongoDB 3.0 to 3.2

    • Type: Icon: Bug Bug
    • Resolution: Done
    • Priority: Icon: Minor - P4 Minor - P4
    • None
    • Affects Version/s: None
    • Component/s: WiredTiger
    • Labels:
      None
    • ALL

      Original summary

      iowait, softirq and ssytem CPU usage drastically changed from upgrading MongoDB 3.0 to 3.2

      Original description

      Hello,

      Last night I upgraded my MongoDB 3.0.9 to 3.2 in a rolling upgrade and it went ok. But I have noticed the CPU usage both on the machines and MMS that some parameters have changed drastically. It is noticeable from 2 screenshots I attached (before upgrade and after)

      It is also noticeable when I am SSH to the machine every 20-30 seconds it freezes for a sec or two.

      Details:

      Machines:
      2x VM Ubuntu 14.0.4 LTS
      80GB RAM and 10 core of CPU

      Running replica:
      mongod --storageEngine wiredTiger --dbpath /data/ --replSet rs0 --fork --logpath /data/fork.log

      MongoDB shell version: 3.2.3
      rs0:PRIMARY> db.stats()
      {
              "db" : "test",
              "collections" : 77,
              "objects" : 3766991607,
              "avgObjSize" : 782.8079483321238,
              "dataSize" : 2948830971260,
              "storageSize" : 1500816666624,
              "numExtents" : 0,
              "indexes" : 205,
              "indexSize" : 49011482624,
              "ok" : 1
      }
      

      Some mongostat --discover

       localhost:27017   *149     3    *21     *0       0    13|0     0.5   21.9       0 11.1G 10.4G   0|0   0|1    2k   130k  102 rs0  SEC 2016-03-02T12:42:10+01:00
      mongodb-replica1:27017    182    *0     23     *0     134    84|0     0.4   21.3       0 10.8G 10.0G   0|0   0|0  289k   323k  112 rs0  PRI 2016-03-02T12:42:11+01:00
      mongodb-replica2:27017   *149     3    *21     *0       0    13|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0    2k   130k  102 rs0  SEC 2016-03-02T12:42:10+01:00
      
             localhost:27017    *98     6    *22     *0       0    12|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0    2k   235k  102 rs0  SEC 2016-03-02T12:42:11+01:00
      mongodb-replica1:27017     94    *0     36     *0     129    77|0     0.4   21.3       0 10.8G 10.0G   0|0   0|0  189k   200k  112 rs0  PRI 2016-03-02T12:42:12+01:00
      mongodb-replica2:27017    *98     6    *22     *0       0    11|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0    2k   217k  102 rs0  SEC 2016-03-02T12:42:11+01:00
      
             localhost:27017    *78    10    *30     *0       0     3|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0    3k   376k  102 rs0  SEC 2016-03-02T12:42:12+01:00
      mongodb-replica1:27017     72    *0     31     *0     113    64|0     0.5   21.3       0 10.8G 10.0G   1|0   0|0  153k   163k  112 rs0  PRI 2016-03-02T12:42:13+01:00
      mongodb-replica2:27017    *78    10    *30     *0       0     3|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0    3k   376k  102 rs0  SEC 2016-03-02T12:42:12+01:00
      
             localhost:27017    *76     6    *24     *0       0     5|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0    2k   215k  102 rs0  SEC 2016-03-02T12:42:13+01:00
      mongodb-replica1:27017     69    *0      4     *0      93    44|0     0.5   21.3       0 10.8G 10.0G   0|0   0|1   98k   115k  112 rs0  PRI 2016-03-02T12:42:14+01:00
      mongodb-replica2:27017    *75     6    *24     *0       0     5|0     0.5   21.9       0 11.1G 10.4G   0|1   0|0    2k   215k  102 rs0  SEC 2016-03-02T12:42:13+01:00
      
             localhost:27017    *79     3     *4     *0       0     3|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0  900b   107k  102 rs0  SEC 2016-03-02T12:42:14+01:00
      mongodb-replica1:27017     73    *0     17     *0     102    52|0     0.5   21.3       0 10.8G 10.0G   0|0   0|0  136k   149k  112 rs0  PRI 2016-03-02T12:42:15+01:00
      mongodb-replica2:27017    *80     3     *4     *0       0     4|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0  979b   126k  102 rs0  SEC 2016-03-02T12:42:14+01:00
      
             localhost:27017    *69     6    *24     *0       0     7|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0    2k   215k  102 rs0  SEC 2016-03-02T12:42:15+01:00
      mongodb-replica1:27017     76    *0     18     *0     107    59|0     0.5   21.3       0 10.8G 10.0G   0|0   0|0  133k   667k  112 rs0  PRI 2016-03-02T12:42:16+01:00
      mongodb-replica2:27017    *69     6    *24     *0       0     8|0     0.5   21.9       0 11.1G 10.4G   0|0   0|0    2k   215k  102 rs0  SEC 2016-03-02T12:42:15+01:00
      
             localhost:27017    *80     6    *11     *0       0    13|0     0.5   22.0       0 11.1G 10.4G   0|0   0|0    2k   552k  102 rs0  SEC 2016-03-02T12:42:16+01:00
      mongodb-replica1:27017     76    *0     18     *0     107    59|0     0.5   21.3       0 10.8G 10.0G   0|0   0|0  133k   667k  112 rs0  PRI 2016-03-02T12:42:16+01:00
      mongodb-replica2:27017    *80     6    *11     *0       0    12|0     0.0   22.0       0 11.1G 10.4G   0|0   0|0    2k   552k  102 rs0  SEC 2016-03-02T12:42:16+01:00
      
             localhost:27017    *84     3    *16     *0       0     5|0     0.5   22.0       0 11.1G 10.4G   0|0   0|0    1k   145k  102 rs0  SEC 2016-03-02T12:42:17+01:00
      mongodb-replica1:27017     84    *0     14     *0     101    54|0     0.5   21.3       0 10.8G 10.0G   0|0   0|0  140k   154k  112 rs0  PRI 2016-03-02T12:42:17+01:00
      mongodb-replica2:27017    *84     3    *16     *0       0     4|0     0.5   22.0       0 11.1G 10.4G   0|0   0|0  989b   127k  102 rs0  SEC 2016-03-02T12:42:17+01:00
      
             localhost:27017    *11     5     *7     *0       0     3|0     0.5   22.0       1 11.1G 10.4G   0|1   4|0  243b    19k  102 rs0  SEC 2016-03-02T12:42:19+01:00
      mongodb-replica1:27017    124    *0     29     *0      35    16|0     0.5   21.3       0 10.8G 10.0G   0|0   0|0  168k   113k  112 rs0  PRI 2016-03-02T12:42:19+01:00
      mongodb-replica2:27017    *11     5     *7     *0       0     4|0     0.5   22.0       1 11.1G 10.4G   0|1   4|0  322b    37k  102 rs0  SEC 2016-03-02T12:42:19+01:00
      
             localhost:27017   *184    10    *37     *0       0     4|0     0.4   22.0       0 11.1G 10.4G   0|0   0|0    4k   480k  102 rs0  SEC 2016-03-02T12:42:20+01:00
      mongodb-replica1:27017     92    *0     17     *0     100    45|0     0.5   21.3       0 10.8G 10.0G   0|0   0|0  135k   229k  112 rs0  PRI 2016-03-02T12:42:20+01:00
      mongodb-replica2:27017   *184    10    *37     *0       0     5|0     0.4   22.0       0 11.1G 10.4G   0|0   0|0    4k   480k  102 rs0  SEC 2016-03-02T12:42:20+01:00
      

      Please let me know if you need more info.

      Best,
      Maziyar

        1. cache_activity.png
          cache_activity.png
          67 kB
        2. cpu_stats.png
          cpu_stats.png
          52 kB
        3. diagnostic.data.zip
          12.82 MB
        4. diagnostic.data-primary.zip
          41.37 MB
        5. diagnostic.data-secondary.zip
          66.87 MB
        6. iostat30.log.zip
          248 kB
        7. iostat32.log.zip
          247 kB
        8. iostat-primary.log
          7.92 MB
        9. iostat-secondary.log
          7.91 MB
        10. Screen Shot 2016-03-02 at 12.35.49.png
          Screen Shot 2016-03-02 at 12.35.49.png
          220 kB
        11. Screen Shot 2016-03-02 at 12.36.11.png
          Screen Shot 2016-03-02 at 12.36.11.png
          227 kB
        12. Screen Shot 2016-03-21 at 22.01.58.png
          Screen Shot 2016-03-21 at 22.01.58.png
          124 kB
        13. screenshot-cloud.mongodb.com-2016-09-15-12-30-25.png
          screenshot-cloud.mongodb.com-2016-09-15-12-30-25.png
          77 kB
        14. ss.log.zip
          2.46 MB

            Assignee:
            kelsey.schubert@mongodb.com Kelsey Schubert
            Reporter:
            maziyar Maziyar Panahi
            Votes:
            0 Vote for this issue
            Watchers:
            9 Start watching this issue

              Created:
              Updated:
              Resolved: