Using Semantics for Policy-Based Web Service Composition

Abstract

Abstract. Proliferation of Web technologies and the ubiquitous Internet has resulted in a tremendous increase in the need to deliver one-stop Web services, which are often composed of multiple component services that cross organizational boundaries. It is essential that these Web services, referred to in this paper as service flows, be carefully composed in a dynamic and customized manner to suit to the changing needs of the customers. This composition should be conducted in such a manner that (i) the composed service flow adheres to the policies imposed by the organizations offering the component services, (ii) the selected component services are compatible with one another so that the entire composition would result in a successful service flow, and (iii) the selected component services most closely meet the customer requirements. In this paper, we propose a policy-based Web service composition that utilizes the semantics associated with the component services.We consider policies imposed by different entities while composing service flows, which include service policies (imposed by the organizations offering component services), service flow policies (associated with the entire service flow), and user policies (the user requirements expressed as policies). In addition to these policies, one may consider rules at the syntactic and semantic levels that can be used to select relevant component services in order to compose customized service flows, by considering the notions of syntactic, semantic and policy compatibility. We model the different policies and the service topic ontology using OWL, DAML-S, RuleML and RDF standards.

On Using WS-Policy, Ontology, and Rule Reasoning to Discover Web Services

“…Their use of policy allows services to be described as requiring encrypted input or servicing with data privacy, and therefore service consumers can query for services that exhibit these policyaware aspects. The work in [8] is closer to our work in that the policy will be defined using OWL and RuleML. Policy compatibility is considered in service composition but they do not consider deploying their mechanism onto standard UDDI or WSpolicy framework.…”

Dynamic Policy Enforcement Using Restriction Set Theoretic Expressions (RSTE)

“…Goal oriented and formal logic based frameworks have also been propped in the past for policy management [10], but their capabilities are limited by the underlaying OWL version. Other semantic representation based frameworks such as [11], [12] have also been proposed. Deontic logic based approaches to address paradoxes in Standard Deontic Logic (SDL) have been proposed in [13], however, our approach differ from deontic logic based approaches and other formal logic based approaches such as [14], [10] in policy representation as well as enforcement because the latter are not feasible for dynamic compositions of services.…”

The Design and Enforcement of a Rule-based Constraint Policy Language for Service Composition

“…Service composition is subject to a variety of constraints in terms of functionality, QoS requirements, security and privacy policies [11], [12], [17]. For example, the discovery process usually requires that the functionality offered by a service provider be matched with that required by the service.…”

“…It recently has received a great amount of attention [11], [12], [17]. Carminati et al [11] focused on security constraints of web service composition.…”