Restart Jboss server make it slower

[cidylong]

We got a Jboss application runs on Windows 2000 advanced server.

After we updated some code and redeploy it online, the performance is much slower than it as before.

After redeployed, our QA team try to access each JSPs to make sure every jsp was compiled.

When system went couple of days, it speed up to normal.

So Why Jboss server get this behavior? Any cache mechnism to help speed up? Or what ever?

Please help me on this issue!

[camel]

I can think of two reasons:

1) This only applies to the JSPs: JSPs must be converted into a servlet class and then compiled into a .class file when they are changed or redeployed (by default). This is very slow, but only happens once normally. (There is a JBoss option to not remove the work directories, and I believe there is also a way to pre-compile all your JSPs).

2) The Sun server VM (which JBoss uses by default, I believe) profiles and compiles sections of code to native code as the server runs. However, it doesn't do it immediately. So that would explain why the server might speed up after running for a while.

The JBoss gurus may have some other reasons and ways to "fix" it.