Hi Stephen, Could you try to use jmap -dump and/or jmap -histo to see the names of the instances being created?
You could also have a look at VisualVM in order to profile the application. https://visualvm.dev.java.net Regards, Luis > On 4/9/2008 3:24 PM, Stephen Ryan wrote: > > Hi Alan, > Thanks for that but Im not sure its that at all. I've other servers > being monitored and Ive never seen jConsole have this effect. I did a > jmap on the server and saw some huge numbers. Im begining to think that > theres bad code thats causing classes to be loaded too many times. The > 'Classes' view in jConsole is showing me a constant rise in class > numbers. I would have expected this to be more or less stable, > considering that the server is serving about 4 requests per second. The > CPU is pretty busy too.Busy garbage collecting the eden space I guess. > > I was considering increasing the eden space to see if that alleavates > the problem, but if its a code problem, it wont help at all. > > Thanks! > Stephen. > > Alan Bateman wrote: > >> Stephen Ryan wrote: >> >>> Hi, >>> >>> I was wondering if its possible to get the size of the classes loaded >>> from jConsole. Im seeing a lot of GC's in the Eden Space in a server >>> thats basically doing nothing. Im thinking that the jvm is trying to >>> load classes in there that are just too close to the size of that space. >>> >>> Any help appreciated! >>> >>> Stephen. >> >> Classes are essentially allocated from the perm generation so I don't >> think this is what you are observing. Instead it is likely that you >> are observing the effect of the JMX agent in the target VM due to the >> polling by jconsole. Each time jconsole updates the display it must >> interact with agent in the agent VM so this means some objects are >> allocated which can lead to periodic scavenging that you observe. You >> can reduce the polling interval via jconsole's -interval=value option >> (interval is specified in seconds). The management interface for class >> loading doesn't include the size of the classes but if you try jstat >> then you can get this information (jstat -class <vmid> for example). >> >> -Alan.
