Memory Leak in web application created using j2ee

Hi,
Our company has one web application, provided by "X" vendor. this application has many JSPs and many TLDs used. The basic behaviour of the apoplication is to connect to the database (Oracle) get the information and show it to the user.
We deployed this web application in Tomcat 5.0.25 in the windows environment. One thing we observed here is, when we login to the application the tomcat5.exe process increses its memory. and when we logout, it does not come down to the original position. similar things happen when we search for some of the data using there provided searches.
We have some code developed which uses httpclient to login to this web application (created for performace testing). This code initially logs in 50 users which goes fine, then logs in 100 users which also goes fine but after this 100 users we ran the code for 50 users agian but this time it threw OutOfmemory exception:Java heap space error.
we are observing the memory in the Task Manager in windows.
Can anyone tell me what could be the cause of this? is it the web application causing problem or is tomcat caching some pages into the memory and is not releasing them?

Hi,
Few questions!
1> Have you tweaked your jvm?
2> What are the values given for Xms and Xmx?
3> What is the size of XX:MaxPermGen?
4> How much RAM is available on the system where you have deployed your app?
5> Are you using pre-complied JSPs for faster response?
6> Which JDK are you using?
7> Have you tried using latest version of Tomcat?
8> If these doesnt help, use any profiler to find the leak. <JProfiler, JVMTI, YourKit profiler etc>
I hope answering these questions would help you :)
njoy!

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