Re: java.lang.OutOfMemoryError
For the latest versions of 1.4.2 (_10 and up) and 5/6 there is a very useful utility called jmap - http://java.sun.com/j2se/1.5.0/docs/tooldocs/share/jmap.html that's built into the Java SDK. This dumps out all the objects in the heap. Doesn't work under windows though.. Joe On 30/12/06, Thomas Fischer <[EMAIL PROTECTED]> wrote: An out of memory error is typically very difficult to pinpoint. The place where this error occurs is typically not connected to the place where the problem sits. Personally, I know of two ways of dealing with this - you can have an idea what happens. The answers before have provided situations where OutOfMemory-Problems typically happen. - If you think that none of the typical causes apply to you, you have to find out the hard way. To get an idea of the cause of the problem, create a heap dump of the virtual machine just after an OutOfMemory-Error occured (on linux, this is done by using the "kill -3" command on the appropriate process). Then, scan through the heap dump to see which objects occur most often. These are usually the objects which are not dereferenced and cause the memory overflow. Then go through the code and find out where these objects are created, and why they are not thrown away after being used. You might need more information out of the heap dump than just the class names of the relevant object; there are tools showing the refences out of heap dumps but I never used one myself. Hope this helps, Thomas On Mon, 18 Dec 2006, jill han wrote: > What could cause java.lang.OutOfMemoryError ? > The application is built on turbine/torque/velocity. > > Thanks in advance > > Jill > > > - > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: java.lang.OutOfMemoryError
An out of memory error is typically very difficult to pinpoint. The place where this error occurs is typically not connected to the place where the problem sits. Personally, I know of two ways of dealing with this - you can have an idea what happens. The answers before have provided situations where OutOfMemory-Problems typically happen. - If you think that none of the typical causes apply to you, you have to find out the hard way. To get an idea of the cause of the problem, create a heap dump of the virtual machine just after an OutOfMemory-Error occured (on linux, this is done by using the "kill -3" command on the appropriate process). Then, scan through the heap dump to see which objects occur most often. These are usually the objects which are not dereferenced and cause the memory overflow. Then go through the code and find out where these objects are created, and why they are not thrown away after being used. You might need more information out of the heap dump than just the class names of the relevant object; there are tools showing the refences out of heap dumps but I never used one myself. Hope this helps, Thomas On Mon, 18 Dec 2006, jill han wrote: What could cause java.lang.OutOfMemoryError ? The application is built on turbine/torque/velocity. Thanks in advance Jill - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: java.lang.OutOfMemoryError
When does the occur? You *will* get an OOM error if you are constantly reloading a webapp from the tomcat manager. Im not sure of the exact cause, many people have written about it all over the web. Its something to do with having to use a new Classloader each time a webapp is restarted. Here is one such article. http://www.mail-archive.com/tomcat-dev@jakarta.apache.org/msg42351.html -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Monday, December 18, 2006 12:53 PM To: Apache Torque Users List Subject: Re: java.lang.OutOfMemoryError I've had this error occur when I'm continously making changes to my app, and the app server is re-compiling jsps and classes. Restarting the app server has resolved this for me. Your cause may be very different. :-) Thank you, Adam "jill han" <[EMAIL PROTECTED] m> To "Turbine Users List" , 12/18/06 02:41 "Apache Torque Users List" PM , "Velocity Users List" Please respond cc to "Apache TorqueSubject Users List" java.lang.OutOfMemoryError <[EMAIL PROTECTED] b.apache.org> What could cause java.lang.OutOfMemoryError ? The application is built on turbine/torque/velocity. Thanks in advance Jill - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: java.lang.OutOfMemoryError
Lots of things. I find the default Java Heap memory settings in Java to be inadequate for a typical webapp. Are you familiar with the -Xmx setting? Have you read this? http://tomcat.apache.org/faq/memory.html WILL On 12/18/06, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: I've had this error occur when I'm continously making changes to my app, and the app server is re-compiling jsps and classes. Restarting the app server has resolved this for me. Your cause may be very different. :-) Thank you, Adam "jill han" <[EMAIL PROTECTED] m> To "Turbine Users List" , 12/18/06 02:41 "Apache Torque Users List" PM , "Velocity Users List" Please respond cc to "Apache TorqueSubject Users List" java.lang.OutOfMemoryError <[EMAIL PROTECTED] b.apache.org> What could cause java.lang.OutOfMemoryError ? The application is built on turbine/torque/velocity. Thanks in advance Jill - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] -- Forio Business Simulations Will Glass-Husain [EMAIL PROTECTED] www.forio.com - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: java.lang.OutOfMemoryError
I've had this error occur when I'm continously making changes to my app, and the app server is re-compiling jsps and classes. Restarting the app server has resolved this for me. Your cause may be very different. :-) Thank you, Adam "jill han" <[EMAIL PROTECTED] m> To "Turbine Users List" , 12/18/06 02:41 "Apache Torque Users List" PM , "Velocity Users List" Please respond cc to "Apache TorqueSubject Users List" java.lang.OutOfMemoryError <[EMAIL PROTECTED] b.apache.org> What could cause java.lang.OutOfMemoryError ? The application is built on turbine/torque/velocity. Thanks in advance Jill - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
