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From Vadim Gritsenko <>
Subject Re: AW: Cocoon performance results
Date Tue, 27 Jan 2004 11:28:24 GMT
Rottmann, Lars wrote:

>Hi Vadim,
>sorry, I don't see it. Where is the problem if I set the JVM memory to 2536M
>= 2,536,000,000 and heapsize and freememory to 80,000,000 and 20,000,000?
>Can you give me a hint?

      | Store Janitor: the store garbage collector and memory usage controller.
      | WARNING: Be careful with the heapsize and freememory parameters.
      |           Wrong values can cause high cpu usage.
      | Example configuration:
      | Jvm settings:
      |    -Xmx200000000
      | store-janitor settings:
      |    <parameter name="freememory" value="5000000"/>
      |    <parameter name="heapsize" value="196000000"/>
      | It is recommended to have heapsize equal to -Xmx, especially on Sun's
      | JVM which are unable to shrink its heap once it grows above minimum.
      | Freememory should be greater than amount of memory necessary for normal
      | application operation.
      | BUT: The heap size of the memory of the JVM is a little bit less than
      |      the value you specify for -Xmx, so you have to set the heapsize
      |      for the store janitor to a value which is lower (2% less seems
      |      to be a working value).

It advises to have heapsize set to the -Xmx value. In your particular 
situation (-Xms has same vaue as -Xmx) it might not cause any problem, 
but I it is not generally advised to have conflicting values.

Actually, it is more hazardous to specify heapsize which is just one 
byte more than really possible heapsize - this could turn off janitor.


>-----Urspr√ľngliche Nachricht-----
>Von: Vadim Gritsenko [] 
>You know that you've got conflicting settings, right?
> From the page:
>    -Xms2536M -Xmx2536M
>    store-janitor's /heapsize/ set to 80,000,000, /freememory/ set to 
>20,000,000 (cocoon.xconf)

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