Chapter 1 Service Discovery Luis

Semantic service discovery is the process of locating Web services based on the description of their functional and non-functional semantics. Both service oriented computing and the semantic Web envision intelligent agents to proactively pursue this task on behalf of their clients. Service discovery can be performed in different ways depending on the service description framework, on means of service selection, and on its coordination through assisted mediation or in a peer-to-peer fashion. In the CASCOM system, semantic service discovery is realised by the interplay between a service discovery agent (SDA), a project distributed service repository (WSDir), and a semantic service matchmaker (SMA). On request, the SDA searches for relevant services in both the WSDir and in its own local service repository. Service selection is implemented through means of a rather coarsegrained keyword based matching of services as a quick filtering operation by the SDA which is complemented by a more fine-grained logic based analysis of service semantics by the SMA. This chapter is structured as follows. First, we provide an overview of the discovery approach based on the interaction between SDA, WSDir, and SMA. This is followed by a more detailed description of both agents, the SDA and the SMA with focus on the integrated service matchmaking algorithms. The chapter ends with a conclusions section.