Rania Khalaf

Former Research Associate


Thesis Outline

In the SOA world, the core task of application integration has become the complex yet equally vital task of service aggregation in a world where one must relinquish control of the parts making up one’s (now-heavily-distributed) applications. We are mainly concerned with the aggregation of service oriented applications, focusing on BPEL4WS and its related and complimentary technologies. We take a deep look at BPEL’s combination of flat-graph and structured approach to process definition by formalizing the use of scopes and the propagation of fault handling, and the design time computation of compensation order for mixed models such as BPEL where links cross scope boundaries. Applications are created either top-down from a global process description or bottom-up. For the former, one defines directly a process for each service, such as our work on RosettaNet. For the latter, we provide a mechanism to break down a business process among different participants based on allocation of work items, instead of on partner message exchanges. We aim to support the graph-based processes that include loops, fault handlers, and transactional scopes. We will use coordination protocol for features beyond graph-based control flow. Whether one connects applications top-down or bottom-up, a wiring model is still required to define the connections of these applications in relation to each other. Additionally, there should preferably be some flexibility in how the services get ahold of the EPRs of their partners.