Distributed Processing over Stand-alone Systems and Applications

This paper describes the architecture of OPERA, a generic platform for building distributed systems over stand alone applications. The main contribution of this research effort. is t,o propose a “kernel” system providing the “essentials” for distributed processing and to show the important role database technology may play in supporting such functionality. These include a powerful process management environment. created as a generalization of workflow ideas and incorporating transactional notions such as spheres of isolation, atomicit.y, and persistence and a transactional engine enforcing correctness based on the nested and multi-level models. It also includes a tool-kit providing externalized database functionality enabling physical database design over heterogeneous data repositories. The potential of the proposed platform is demonstrated by several concrete applications currently be-