On Fri, 6 Oct 2006 00:39:30 +0530 "Manish Kathuria" <[EMAIL PROTECTED]> wrote: > On 10/5/06, Ajitabh Pandey अिजतााभ पांडे <[EMAIL PROTECTED]> wrote: > > Very recently (around a month or so back) the system is appearing more > > busier and some slowness has also been reported by users. > Did you do any changes around that time ?
Nope not from my side, but the release team did released a new version of our customised application two-three weeks before users started complaining. > Which kernel are you using ? You can try tweaking the parameters in > /proc/sys/vm BUT only after understanding them very well. I would > rather avoid it. Its RHEL AS 3 in 32 bit mode on a 64-bit h/w, so the kernel is 2.4 > > (2.) At times I have seen that even if I had 10GB of free RAM the > > system was still swapping. Infact I havent seen the swap space zero at > > any point of time on these servers. Why? > > The swap space statictics over a 6 weeks period are - > > Server 1 - average swap usage 170MB and max usage 1GB > > Server 2 - average swap usage 194MB and max usage 2GB > > Increase in swap usage has been observed when number of java xml > > transformations are running. > > It is quite possible that kernel is making a wrong choice and swapping > unnecessarily. When some application needs memory and all the RAM is > used the kernel can either reduce the disk cache in the RAM by > eliminating the oldest data or it may swap some pages to hard disk. Well, ok so if more than 90% of RAM is cached and still kernel decides to swap and swap little (like couple of hundred megs) then its not good thing. The swap space usage is low, but IMO if I have lots of RAM as cached it should not be there. > If you are using a 2.6 kernel, you can actually tune swappiness. There > is a parameter /proc/sys/vm/swapiness which can be assigned a value > between 0 and 100 to either eliminate or always force swapping. You > can also use /etc/sysctl.conf to set the value of vm.swappiness when > the system boots up. Thanks for the input, this will be useful when new build of RHEL AS 4 in amd-64 mode comes live in couple of months. > > The application (which includes java code) is heavy on CPU (which is > > maxed out almost all the times). > Is your application releasing memory when not using it. Ok, now this is a very stable code (though very-very old and uses saxon parser libraries and IBM Java, it doesn't run on Sun Java for some reason) running from last couple of years at-least and never needed any change. Had there been problems like app not releasing memory then a reboot should have fixed the slowness. Also I cant see any real more memory utilisation on any of the graphs since the slowness has been reported. > What is the size of the java process ? There might not be any memory > leaks but its very much possible that your application is not releasing > memory. How do I measure size of the java process? How do I find out if the application is not releasing memory Thanks for replying. Regards. -- Ajitabh Pandey http://www.ajitabhpandey.info/ ICQ - 150615062 Registered Linux User - 240748 GnuPG Key ID - C2AED210 Key fingerprint = 8A56 0684 44C2 3373 D441 20AF 7398 4DEB C2AE D210 ----------------------------------- Q: What do you call a half-dozen Indians with Asian flu? A: Six sick Sikhs (sic). -- Ajitabh Pandey http://www.ajitabhpandey.info/ ICQ - 150615062 Registered Linux User - 240748 GnuPG Key ID - C2AED210 Key fingerprint = 8A56 0684 44C2 3373 D441 20AF 7398 4DEB C2AE D210 ----------------------------------- It usually takes more than three weeks to prepare a good impromptu speech. -- Mark Twain ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-india-help mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-india-help
