Losing connection to db with many users

[Silvio Rainoldi]

Hi all,
I'm using tomcat 6 + mysql + c3p0 connection pools + hibernate.
If i test my web application with Apache JMeter simulating 100 users
(threads?!) in a page, after 5-30 seconds i will lose the connection to db.
If I redeploy the application it work again... In the tomcat manager I see
15'000/18'000 sessions :S
Please help me and sorry for my bad english