The best way to solve  this problem is by using Jini & JavaSpaces
specification. See:
http://wwws.sun.com/software/jini/specs/
http://wwws.sun.com/software/jini/specs/js2_0.pdf

This allows you to have your session/transaction info between
different processes.
There are several implementations. The following also support JCA
that works great with WSAD 5.1:
http://www.gigaspaces.com
I have found also nice document describes how this works:
http://www.gigaspaces.com/docs/J2EE/doc/BuildingEnterpriseApplications
withWebSphere5andGigaSpaces3.pdf