We are to measure and record statics for a web-site, for a 10,000 user load. we have to measure CPU, Memory, etc. But this site accepts only unique logins. So we have written a small java application using servlets and jsps to retrive a user-name/pwd pair every time a user logs in. This application is hosted on a JBoss server. In short, before a virtual user logs in to the application under test , he actually retrieves a user-name/pwd pair, and uses these credentials to log in to the application under test. This application which gives out user-names/pwd pairs is deployed on JBoss( A list of 10,000 uid/pwds are maintained in a .csv file).A servlet reads a line at a time and gives it to the user. Since we cannot log in 10,000 users at the same time, we are ramping up 50 users every minute. So there are 50 hits on the the servlet(deployed on JBoss) every minute. Till the first 50 users are ramped up, JBoss performs flawlessly returning uid/pwd pair, but as users are ramped up, it starts giving out blank lines ever now and then. As more users are ramped up, more of these lines appear. The file object the servlet opens is not being closed, because file open-close is a very resource intensive operation. So once a file is opened, its object is closed only when EOF is reached. We are using 200 different machines as load generatods, there by generating a load a 50 users per machine. All machines are 512 RAM, 40 GB hard-drives, Pentium 4 at 3.0 giga Hertz. Java Version 1.5.0_05. JBoss Version 4.0.2.
My question is this : Is there some setting in JBoss that i can tweak so that it can accept more incoming connections, if that is what the problem is? I would also like suggestions so as to understand why this might be happening and how i can avoid it?