Topic
  • 5 replies
  • Latest Post - ‏2012-05-30T17:20:30Z by SystemAdmin
SystemAdmin
SystemAdmin
102 Posts

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

    Re: ODR Initial JVM Heap Size setting

    ‏2012-05-30T12:25:41Z  
    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

    Re: ODR Initial JVM Heap Size setting

    ‏2012-05-30T12:28:00Z  
    • KeithS
    • ‏2012-05-30T12:25:41Z
    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
    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

    Re: ODR Initial JVM Heap Size setting

    ‏2012-05-30T14:13:02Z  
    • KeithS
    • ‏2012-05-30T12:28:00Z
    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
    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?
  • KeithS
    KeithS
    17 Posts

    Re: ODR Initial JVM Heap Size setting

    ‏2012-05-30T15:39:50Z  
    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?
    Yes, and yes.

    Keith
  • SystemAdmin
    SystemAdmin
    102 Posts

    Re: ODR Initial JVM Heap Size setting

    ‏2012-05-30T17:20:30Z  
    • KeithS
    • ‏2012-05-30T15:39:50Z
    Yes, and yes.

    Keith
    Awesome! Thanks!!