Troubles with Websphere / OJB / Oracle application

[J Pielage <pi...@fel.tno.nl>]

Hi all,

We are stress testing an J2EE application on Websphere App Server 4.0.3
and running into problems. We use OJB v 0.9.7 for the data layer,
instead of entity EJB's. The OJB functionality is called from a layer of
stateless session EJB's.

The problem is that, when running requests from different clients at the
same time, numerous requests to the database time out, likely because of
problems with getting a database connection.
We use an Oracle (9.0.1) connection pooled datasource from OJB. When
stress testing normal JDBC calls (not involving OJB) using the same
datasource, we experience no problems. 

So the problem is maybe in the configuration of the OJB layer. 
We tried several settings in the OJB.properties file, especially setting 
the ConnectionFactoryClass to ConnectionFactoryNotPooledImpl instead of
the ConnectionFactoryManagedImpl (to make sure connections get closed,
that is returned to the data source connection pool) but that didn't
help.

We are currently running late with our project and running out of ideas,
so if any of you could give us timely advice on this one, it would be
deeply appreciated. Especially, if you have experiences with a
production system with a similar architecture, it would be very helpful
to know how you did configure OJB.

Thanks!

Jeroen Pielage
TNO
the Netherlands