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  1. Core Server
  2. SERVER-22274

WiredTiger cache size is only configurable in whole gigabytes.

    • Type: Icon: Bug Bug
    • Resolution: Cannot Reproduce
    • Priority: Icon: Minor - P4 Minor - P4
    • None
    • Affects Version/s: 3.0.8
    • Component/s: WiredTiger
    • None
    • ALL

      Hello, on our development servers we currently run our application server alongside a standalone mongod instance. Ever since WiredTiger was introduced we have the occasional OOM killer issue where app server RAM + WT cache + file system buffers are way higher than these smaller instances have.

      I was looking into overriding the WT cache size into something smaller and found this option:

      The problem is that this only allows this value to be specified in whole gigabytes while total RAM of these instances is only 1 or 2 Gb. Specifying this value as a fraction results in parse errors as this field is parsed as an integer. I also tried other key names such as 'cacheSizeMB' or 'cacheSize' without any luck. I also tried using a letter as in indicator ('200M') but that leads to another parsing error.

      I found a workaround in this post but that does not seem to work (anymore?):

      Are there plans to specify this value in a more specific way. Also, is there a current workaround for this?

            kelsey.schubert@mongodb.com Kelsey Schubert
            jeroenv Jeroen Vijfhuizen
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