Hi all.

I have a web application developed with hibernate 3.0
I use tomcat v5.5 and mysql. The application runs very fast and very good in windows (development enviroment) but when I deploy it on linux (also with tomcat and mysql) it stays 2-4 sec on every request to db.

The connection pool size to db is set to 4.

Please can any one help me to find the problem. Where should I start looking for the problem?

10x

could be plenty of things

distance to mysql database
speed of computer
memory available
jdk version
available resources

I don't think there are any direct correlations between hibernate and linux which would make it run slower

the database is located on the same machine
the computer has 4 proc with 2GB memory
jdk is 5.0

So there must be something I do in my code

but in windows on a machine that is 10 times slower it works great

on the windows machine, are you testing the webapp running as a webapp, or just running some junit tests.

try to run a profiler and see where the hang up is occuring

the following aren't linux specific based suggestions, but just some stuff i thought up real quick :)
but, I'd start by checking if you're making too many session factories (more than 1) , duplicating httprequest objects, have large enough queries that consume the connection_pool resources for too long, not closing sessions, the list goes on. ..