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JVM size on Linux RH3 Apache (Oracle 9iAS)

2 replies [Last post]
Joined: 2005-03-16

We have an issue where we need to increase the memory on our JVM on 32 - bit Linux OS past 1.9G addressable. 64 - bit is not an option and nether is hugetbl. are there some settings I am missing to enable the JVM to address more than 1.9 G. I have set Xmx and can allocate 2.6 G but cant address more than that. This is a huge issue that can hold up a critical go live

-any ideas???

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Joined: 2004-01-07

you have 2 options:

* split the app into more pieces
* use a 64-bit cpu & a 64-bit processor. I recommend PPC970 or Opteron.

lg Clemens

Joined: 2005-03-31

I'm affraid, that is not a java issue, but the constraint of 32-bit os. you cannot allocate more than 2gb per process (I've checked it under win and debian). And you cannot assign all of that 2 gb to heap, because java needs some memory for other stuff, like threads stack. Especially in the case of web application, there will be more than a few threads.
I've asked my administrators about it one time, and there is an compile parameter in kernel, which allows increase that limit to 3gb. But I have not tried this option.

so, the bad news is you have to consider migrating system to 64-bit platform or shrink your data structures in memory; maybe soft references will be answer here ?

best regards