I was wrong. There is one JVM and 3 apps in that. But we're seeing it on those that just have 1 app per JVM as well.
I appears some changes that went in last night may have changed the behavior -- a bit too early to tell, more time and testing required there. FP 11 + Generational garbage collection (which also saves it looks like 13% CPU as well). Marcy Cortes "This message may contain confidential and/or privileged information. If you are not the addressee or authorized to receive this for the addressee, you must not use, copy, disclose, or take any action based on this message or any information herein. If you have received this message in error, please advise the sender immediately by reply e-mail and delete this message. Thank you for your cooperation." -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of Dave Jones Sent: Monday, October 22, 2007 9:06 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: [LINUX-390] Another Linux swapping question Well, my colleague Rob v.d. Heij beat me to the punch line, but this was where I was headed....having more than one JVM inside a Linux guest is, imho, asking for trouble. Is there a reason you need to have multiple JVMs running at the same time? Rob van der Heij wrote: > On 10/22/07, Marcy Cortes <[EMAIL PROTECTED]> wrote: > >> Why would a server show such a high amount in cached when it is >> needing to swap? > > In your case, it's probably the JVM heap that is resisting. The JVM > does its own management of the heap. Just like in real life: when you > have multiple managers, you want at most one of them to actually do > something ;-) Once the heap has been given to the JVM, Linux memory > management can not see inside. When Linux cannot manage it, you want > the heap to be resident in the virtual machine. > But one can and should question whether the JVM heap is properly > sized. Some of the rules of thumb in sizing the heap (like "when in > doubt, double it") come from the world of spare memory and may not > apply to Linux on z/VM. The Java Garbage Collector is not as scary as > it used to be. There's options in GC to see high water marks etc that > help you size the heap. I have seen installations so oversize that > after weeks the first GC had not even happened. If you can make it > clean up now and then, you limit the amount of fresh pages and have > more chance to keep those pages resident on VM. That may very well > outweigh the extra cost for GC now and then. > > Rob > -- > Rob van der Heij > Velocity Software, Inc > http://velocitysoftware.com/ > -- DJ V/Soft ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
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