Hello all!

I am currently maintaining a Webflow application on Weblogic 10 on the following versions of software:

Spring Web Flow 2.0.7
Spring 2.5.6
Hibernate 3.2.0
RichFaces 3.3.1

It is deployed on a cluster above 4 nodes (occasionally the cluster will decide to migrate sessions between nodes). Once we restart every node, it just works sweet. However, after a day or two at most, the following problem happens:

We have a main, quite big, flow for the application, from which we spawn some sub-flows (there are 60 different of them; I admit from the beginning it is not well architectured, and it is a matter we must disccus with our provider anyway). There arrives a moment when navigating to any subflow causes a NullPointerException whenever we try to access any subflow-scope variable, and it happens always for every user from that moment in that node! It is not always the same node, there can be 2 or more broken nodes at the same time.

Our application shares every node with another 8 applications, with different architectures, which notice no problems - only our SWF application.

Could it be that we have unknowingly broken something in application context? What could it be?

Thanks a lot in advance!!
Jorge