Hi, You can check the Sun site and places like javaperformancetuning.com for papers on heap versus overall app memory. This has also been addressed several times on this list, so an archive search might prove interesting.
You might have a memory leak: run inside a profiler to see if there are allocated objects still referenced that should be deallocated. If you have a leak, the GC will run and run (longer and longer as your heap grows), but won't be able to collect anything, resulting in the behavior you describe. If you can upgrade your JDK, tomcat, and struts versions you will be in better shape at least as far as receiving support, but also for debugging. Yoav Shapira Millennium Research Informatics >-----Original Message----- >From: Anand Narasimhan [mailto:[EMAIL PROTECTED] >Sent: Friday, May 28, 2004 3:02 PM >To: 'Tomcat Users List' >Cc: 'Anand Narasimhan' >Subject: Memory problems with Tomcat 4.1.27 > >Hi, > >I am trying to debug a memory consumption issue with an application. I >would >appreciate any help I can get. > >The application I am debugging is a web application written using >j2sdk 1.4.1_02 and struts 1.0.2. The tomcat version I am using is >4.1.27. >The backend has a relational database (sybase/oracle) and the database >access >is through JDBC. The tomcat server is running on Solaris 2.8. The max >heap size >for the JVM (using -Xmx) is set to 512M. I tried increasing it to 1024M >as >well. > >The problem is under reasonably large load, the overall process size of >tomcat >(reported by top) keeps increasing and eventually tomcat stops >responding. I >tried running tomcat with OptimizeIt hoping to find out if there are any >leaks. >When running with OptimizeIt the memory consumption increases much >faster than >when running without OptimizeIt. At this point OptimizeIt reports that >about >300M of heap is being used. But the overall process size is about 900M. > >I tried turing on the -Xloggc option. The output of -Xloggc also shows >that >the heap size is well withing the limits. In some cases towards the end >of the >GC log, I noticed that each GC cycle takes about 17 - 20 secs. > >Any suggestions regarding how to proceed debugging this problem would be > >greatly appreciated. Are there any docs or any white papers that would >help >understand the relation between the heap and the overall process memory? > >Thanks >Anand > > >_______________________________________________________________________ _ > >Anand Narasimhan >[EMAIL PROTECTED] > This e-mail, including any attachments, is a confidential business communication, and may contain information that is confidential, proprietary and/or privileged. This e-mail is intended only for the individual(s) to whom it is addressed, and may not be saved, copied, printed, disclosed or used by anyone else. If you are not the(an) intended recipient, please immediately delete this e-mail from your computer system and notify the sender. Thank you. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
