A formal model for the interoperability of service clouds
|Titel||A formal model for the interoperability of service clouds|
|Journal||Service-Oriented Computing and Applications|
Large-scale service-oriented computing is based on the idea that services from various servers are combined into one distributed application. Referring to a collection of services on one server as a service cloud the problem investigated in this paper is to define formal high-level specifications of such distributed applications and to enable the location of suitable services for them. Based on the language-independent model of Abstract State Services (AS2s), which serves as a universal integrated model for data and software as services, we extend AS2s by high-level action schemes called plots as a means to specify permitted sequences of service operations. On these grounds we develop a model for service mediators, i.e. specifications of composed services in which service slots have to be filled by actual services, and investigate matching conditions for slots of mediators and services. For a services to match a slot in a mediator, a (generalised) projection of the mediator must comply with the plot of the service. Furthermore, the service must be semantically adequate, which requires the use of a service ontology.