Topic
5 replies Latest Post - ‏2012-05-30T17:20:30Z by SystemAdmin
SystemAdmin
SystemAdmin
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Pinned topic ODR Initial JVM Heap Size setting

‏2012-05-29T15:30:17Z |
Quick question: I see the following formula used for determining the initial JVM Max Heap Size documented in the VE InfoCenter and Redbooks.

+Initial heap calculation = 90MB + 0.05 MB/req * peak req./sec * Desired time between garbage collections (GC)+

This is compared to the suggested calculation from the IMPACT 2012 VE Best Practices presentation:

+JVM heap size (in MB) = 90 + MR (max requests per second ODR is to handle)+

Is the best practice from the IMPACT 2012 session the new accepted practice?
Updated on 2012-05-30T17:20:30Z at 2012-05-30T17:20:30Z by SystemAdmin
  • KeithS
    KeithS
    17 Posts
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    Re: ODR Initial JVM Heap Size setting

    ‏2012-05-30T12:25:41Z  in response to SystemAdmin
    It turns out that the 2nd formula is a simplification of the 1st formula.
    You can try both and you will come out with the same or very close to the same answer.

    Keith
    • KeithS
      KeithS
      17 Posts
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      Re: ODR Initial JVM Heap Size setting

      ‏2012-05-30T12:28:00Z  in response to KeithS
      To clarify a bit ...
      The 2nd formula is a simplification of the 1st formula in which we determine the recommended time between GCs for you.

      Keith
      • SystemAdmin
        SystemAdmin
        102 Posts
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        Re: ODR Initial JVM Heap Size setting

        ‏2012-05-30T14:13:02Z  in response to KeithS
        Keith,

        Thanks for clarifying. Two follow up questions then:
        • This calculation is for max heap size, correct?
        • For the new calculation, if I expected my ODRs to handle 1000 requests per second then my initial max heap size would be 1090MB, correct?