hi xu, if you cannot find the "jhat" in the bin folder, most probably you were referring to jre folder, instead of jdk folder. i just checked it out, my jdk/bin folder has it, but not the case for my jre/bin folder.
daniel --- daniel baktiar http://savinggaia.tritiumapps.com - saving the planet is everyone's business! On 23 November 2010 19:18, xu cheng <xcheng....@gmail.com> wrote: > hi, Chuck.Caldarale > I referenced to these two links > http://blogs.sun.com/fkieviet/entry/classloader_leaks_the_dreaded_java > http://blogs.sun.com/fkieviet/entry/how_to_fix_the_dreaded > and do as the blog tolds, but failed to find the reason of the oom of my > app... > thanks though.. > > by the way, do you have the the jhat the articals mentioned? I went to the > jdk/bin, > but the jhat there seems not work as the author mentioned. > > > > > 2010/11/23 Daniel Baktiar <dbakt...@gmail.com> > > > hi charles, > > > > please allow me to disagree to that "hanging onto reference" as the main > > issue. > > > > permgen space is garbage collector's specific issue, not general "hanging > > onto reference issue". it is caused by redeployment, which is the > metadata > > for classes, marked to be permanent generation by the hotspot garbage > > collector. when you deploy new classes, the class loader will introduce > > memory usages that will also marked as permanent generation. > > > > permgen is oracle hotspot specific implementation issue. you won't get it > > when you run on oracle jrockit (which performs just in time compilation), > > for example. > > --- > > daniel baktiar > > http://savinggaia.tritiumapps.com - saving the planet is everyone's > > business! > > > > > > > > > > On 23 November 2010 14:10, Caldarale, Charles R > > <chuck.caldar...@unisys.com>wrote: > > > > > > From: xu cheng [mailto:xcheng....@gmail.com] > > > > Subject: Re: OutOfMemoryError some time on some tomcat!!!!1 > > > > > > > I just kept redeploying apps , and the perm gen keep > > > > growing each time I deploy the same app. and when I > > > > undeploy the app, the perm gen didn't clean the garbage > > > > > > Exactly the situation I suggested the other day: you have something > > that's > > > hanging onto a reference to an object from your webapp classes, > > preventing > > > the old webapp deployment from being garbage collected. Again, read > > this: > > > > > > http://wiki.apache.org/tomcat/FAQ/Memory > > > > > > Also, take a look at these: > > > > > > http://blogs.sun.com/fkieviet/entry/classloader_leaks_the_dreaded_java > > > http://blogs.sun.com/fkieviet/entry/how_to_fix_the_dreaded > > > > > > - Chuck > > > > > > > > > THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE > PROPRIETARY > > > MATERIAL and is thus for use only by the intended recipient. If you > > received > > > this in error, please contact the sender and delete the e-mail and its > > > attachments from all computers. > > > > > > > > >
