I am new to GateIn.
Would like to know if it supports struts portlet and transaction management where I can initiate txn with in portlet action, if operation spans across multiple services.
I looked WebUI portlet doc, but am confused as didnt see any service configuration (database entity).
WebUI is just a utility, AFAIK it's not supported. You can try Apache Portals Bridge for Struts support: http://portals.apache.org/bridges/. I didn't try it, don't know if it will work...
Being your portlet a normal application, yes, you can have transaction management features.