Enabling Service Discovery in a Federation of Systems: WS-Discovery Case Study

摘要

NATO has identified Web services as the key enabling technology for NATO Network Enabled Capability (NNEC). The technology provides a means to build loosely coupled distributed systems following the principles of Service- Oriented Architecture (SOA). Interoperability is of paramount importance in a federated environment like a coalition network. As a consequence, systems built using the technology should follow the civil interoperability profiles from WS- I as well as the NATO-specific initiatives like the SOA baseline and the Service Interoperability Profiles (SIPs) that are being developed in the TIDE community. The service invocation paradigms (i.e., request/response and publish/subscribe) are mature and well understood. Also, through initiatives like NATO STO/IST-090, it has been shown that the technology can also be used in tactical environments provided certain adaptations are made. However, there are still challenges related to the discovery of services in the tactical environment. In this paper we discuss the importance of service discovery in a federated system. Further, we look at the Web services discovery standards and discuss their suitability for use in a federated tactical network. Finally, we present a prototype proof-of-concept solution for discovery in a federation leveraging the WS-Discovery standard. This work has been performed in the context of NATO STO/IST-118 SOA recommendations for disadvantaged grids in the tactical domain , the follow-on group to IST-090.