How to allow more than one database connection per machine with JBoss 5 and Oracle

We are 开发者_如何学Ctrying to reproduce an Oracle deadlock issue in our Grails / JBoss 5 / Windows Server 2003 application with The Grinder. We are simulating 800 concurrent users using 8 VM Grinder nodes, but we are only seen one database connection per VM, so somewhere along the line there appears to be some sort of limit.

How can we lift this limit to allow more than one database connection per VM?

Are you trying to connect directly from the Grinder to Oracle? Normally you'd use the Grinder to apply load against your JBoss server, and let JBoss worry about the Oracle connections.

If you really want to go from The Grinder to Oracle, and you want to control exactly how many DB connections you open, it can be done by opening a separate connection for each Grinder threads. Instantiate a new connection in the _init_ method of your TestRunner class. You'll want to avoid using any ORM tools (Hibernate, Ibatis, ...) since they do connection pooling for you and won't let you have direct control of the number of DB connections you open. Use the JDBC API (via jython) instead.