Ok, that makes sense. It sounds like there's a major problem with the iSeries jdk and VM garbage collection. Unless IBM fixes the garbage collection, using another webserver on that box most likely won't help. given that you've profiled it on Suse + tomcat and it performed well, the cause of the bad performance is simply a matter of the VM's GC algorithm on the iSeries. I haven't use the iSeries, but I believe it uses IBM's RISC processor. unless there's another VM/jdk available for iSeries, I don't think there's much to do. only other option is use an older jdk like 1.3.1 and see if the iSeries continues to exhibit the same behavior. peter lin
Pete Stokes <[EMAIL PROTECTED]> wrote: The app is really a basic war file - it uses JTOpen to connect to iSeries. Nothing fancy, a few patterns used, no EJBs etc. Production was rushed onto Tomcat 5.0.16 on a standard Dell desktop with 1gig RAM running SuSE 9, load tested to 150 users. It flies! Page to page times (DB everytime) are incrediblely fast, basically instant even under 150 user load test. On the iSeries, we get over (live objects) 2million Vector object, 2million PCMLDocuments, and a whole host of other big figures. I used JProfiler on the app (Tomcat) and we get nothing like that. IBM seem now to say that we need to *dedicate* 2 processors, 4-6gig of RAM to continue to test the app on an iSeries (820). We are also totally patched up on the iSeries. Interesting figure is that when the iSeries/WebSphere hangs, we shut off the load test and it recovers after 20-30mins with a collected object gc figure of 25million+ compared to a normal 5million. The gc cycles also intermingle. GC cycle 19 starts, and GC 20 then starts before 19 has finished. I have collected loads of info - if you need anything else give me a shout. Regards, Pete. Peter Lin wrote: > >That sounds a bit odd to me. A well designed webapp or ejb shouldn't have horrible >performance for 10 concurrent users. If you're using stateful EJB's you may want to >profile it first. Without knowledge of what the app does, my first guess is something >in the app is eating up all the CPU and memory. > >If the app has been profiled aggressively and you know it's not the app itself, i >would say install the app on JBoss and compare the performance. If you have hard >numbers with the same app, it is much easier to get people to listen. > >you can also d/l weblogic and see how it performs. keep in mind weblogic has a limit >of 10 concurrent connections, so if you need to load test with more than 10 >connections, you'll have to smooze the BEA sales guys. You should be able to get them >to give you a temporary one month license with unlimited connections, since they are >trying to win customers from IBM. > >there are several old benchmarks comparing various servlet containers, which may or >may not help. If you use ejb, those results won't do much for you. if you provide >more details, you'll get better help :) > >peter lin > > > > > >Peter Stokes wrote: >Hi, > >I'm on a site where a third party application has been put on WebSphere 4.0.5 on an >iSeries 820/V5R2. We have had horrendous performance / stability problems even with >10 users and even IBM cannot seem to help. > >Production is currently sitting pretty on a rushed install of SuSE 9 on a Dell >desktop with 1gig RAM and Tomcat. > >What I am after is opinions / a comparason someone has done (weblink?) / docco about >Java webservers performance looking at iSeries, Intel, Sparcs etc. They are into the >iSeries/WebSphere 4.0.5 mindset, but no one can answer why this was the recommended >setup and they seem to be fixed on this route, but no-one can make it work! > >There is nothing else on WebSphere other than this app, so if I can get some info, I >then actually have some stats / papers to help recommendations, if IBM cannot fix >this in the next couple of days (they've had level 1 guys on it for 6 weeks). > >Anything would be a great help. > >Pete. > > > > >*********************************************************************************** >This email and any files transmitted with it are confidential and intended solely for >the use of the individual or entity to whom they are addressed. 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