topic Java Memory Management on HP-UX in Operating System - HP-UX

Java Memory Management on HP-UX

Ivan Azuara — Wed, 19 Sep 2007 13:27:43 GMT

Hi,

I'm trying to Expanding heap size in native applications on HP-UX 11.11 PA-RISC, and find some information about the java memory management.

The application runs on a webserver with BEA Weblogic 8.1 SP6 using java 1.4.2.10. My intention is define 3Gb of memory for one domain. And some documents mention the use of java_q4p.

Somebody have experience in this topic ?.

Thank's in advance.

Re: Java Memory Management on HP-UX

TwoProc — Wed, 19 Sep 2007 17:01:55 GMT

I think you're in luck. Sorta. Pretty much anyways.

I went to the bin directory for that version of java, and ran the following:

$ ./java -Xmx3068M -version

and it started the java engine up and gave me the version information with java 1.4.2.12 on HPUX 11.11.

However, it would not start a 3069M engine up.

BUT!

If you start the engine up at 3068, it leaves no overhead for the java engines' own system level functions to run. In my experience, this will make the engines fail before too long runing your own jobs/programs/etc. So I would start it up with about 100M less than that or so; your mileage may vary.

Try it with an even 3000M and see if your program(s) run(s) reliably, if so you're all set. If you start having unexaplainable problems, you may need to bring it down as far down as 2900M or so. How much you need to back off of the max number(3068M) depends on what and how much you're doing with the java engine of course.

Re: Java Memory Management on HP-UX

whiteknight — Wed, 19 Sep 2007 22:30:18 GMT

Ivan,

You can refer this :-

http://www.hp.com/products1/unix/java/infolibrary/Memory-Management.pdf

I would recommend
Java heap - -Xms500m â Xmx1500m for a start and monitor.

Please ask refer to BEA site for requirement
http://e-docs.bea.com/wls/docs81/perform/index.html

Identify the Best JVM Settings
----------------------------------
http://e-docs.bea.com/wls/docs81/perform/topten.html#1120353

WK
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