This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Jconsole is a monitoring platform and not a profiler. I think you are looking at products like visualVM (free) or Jprofiler (commercial) which profile classes to give you fine grained application and system metrics.
Some profilers might come with sample applications that fail under certain conditions. You can try those or you can invent a scenario yourself. The easiest I can think of is to run an infinite loop or hold on to several object references forever. If you want the best bang out of taking a profiler for a test drive, apply it on a real application with a real problem. You will learn something that way.
thanks for the correction. I will try Visual VM and see how easy it is to use.
My end goal is once this small piece of research is done, I will need to investigate why I am getting 'Perm Gen' issue when deploying 2 web applications on Tomcat. They work individually, but when they are both on the same server the error arises. This also does not happen in development.
The perm gen is used by the JVM to store class metadata information. Perhaps the combined number of classes loaded by both application is too much for the JVM to take. You can use VM arguments to tell the JVM how much perm gen to use. Like so...
Increase the size of the permgen and check if that helps.
Joined: Jul 16, 2012
I have already been advised to make the change. But I wanted to first enquire what is the current size of PermGen on my Windows PC and my Linux server. Would you know the command/tool I need to find this out?
I am just finding it strange that this works on my average PC and not on a server.