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  1. Core Server
  2. SERVER-34402

Abnormal Swap Usage

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    • Icon: Bug Bug
    • Resolution: Works as Designed
    • Icon: Major - P3 Major - P3
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    • 3.2.15
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    Description

      Hi,
      I found an issue running mongodb on a single server.

      Server has following specs:
      8 Core
      16GB RAM
      4GB Swap

      Server has following main application:
      MySQL
      MongoDB

      Sufficient memory is available, but Swap usage remains at 100%.

      $ free -m

                    total        used        free      shared  buff/cache   available
      Mem:          15726       11364         157          53        4204        3932
      Swap:          4095        4095           0
      

      $ ps -ef

      mongod    6453     1  0  2017 ?        1-02:38:03 /usr/bin/mongod -f /etc/mongod-config.conf
      mongod    6879     1  0  2017 ?        1-00:46:58 /usr/bin/mongod -f /etc/mongod-arbiter.conf
      

      $ cat /proc/6453/status |grep -i vmswap

      VmSwap:  3346268 kB
      

      $ cat /proc/6879/status |grep -i vmswap

      VmSwap:    30456 kB
      

      I changed the swappiness setting, but it is the same.
      $ sysctl vm.swappiness

      vm.swappiness = 1
      

      Is there a way to limit mongodb's swap usage?

      + Because I do not speak English well, you may feel my question is strange.

      Attachments

        1. arbiter-diagnostic.data.tar.gz
          55.86 MB
        2. config-diagnostic.data.tar.gz
          66.25 MB

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            Unassigned Unassigned
            minwoo MinwooLee
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              Created:
              Updated:
              Resolved: