High iowait, slow queries, lots of free memory

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    • Type: Bug
    • Resolution: Done
    • Priority: Major - P3
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    • Affects Version/s: 3.2.9
    • Component/s: Performance
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    • 3
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      As of a few days ago, one node is my cluster is suddenly generating many slow queries. The machine is showing very high iowait (sustained > 30%) but cpu of mongod never > 1%. The machine is showing 26GB free memory and 0 swap used. This is the only node sharing with a mysqld process, but I don't understand why mongod is not taking lots of memory like on all other nodes.

        1. Screen Shot 2016-08-31 at 12.52.39.png
          Screen Shot 2016-08-31 at 12.52.39.png
          431 kB
        2. Screen Shot 2016-08-31 at 15.15.19.png
          Screen Shot 2016-08-31 at 15.15.19.png
          395 kB

              Assignee:
              Unassigned
              Reporter:
              Nic Cottrell (Personal) (Inactive)
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                Created:
                Updated:
                Resolved: