Web-oriented Architecture - Network-based Defence development made easier
Mikael Kirkeby Fidjeland, Bård K. Reitan · 2009
ion Resources Methods Integration Hypermedia, web of data. Many and open ended integration points Business processes. Few and well-defined integration points Presentation Interfaces for both humans and machines, unrestricted data representation Only machine interfaces, only XML as data representation Security Application layer authentication, transport layer encryption. Hostto-host security. WS-* protocols for security. Process-to-process security possible. Table 5.1: WOA+REST versus SOA+SOAP 5.2.1 Control In an enterprise, solutions are usually developed with the assumptions that there is single authority charge – someone is control. As long as these assumptions hold, it is possible to force standardization and minimize heterogeneity. Further, intrusive solutions and strongly dependent services are still possible. SOA+SOAP is primarily applied where this assumption of one architect holds. For long this has been a reasonable assumption, but as systems become larger, includes entities outside the organization, the span of this single authority is challenged (CTSB, 2000). Nevertheless, it is mostly such environments that SOA+SOAP has evolved and has been deployed; with a centralized and bureaucratic orchestration to achieve interoperability. FFI-rapport 2009/01784 37 The environment from where WOA+REST has evolved is very different. Most important, on the Web there is no single authority no is in control of the overall system. Heterogeneity is a given, and homogeneity is Utopia. Interoperability is reached by open, published interfaces and by adaptation, rather than coordination and making deals. Intrusiveness and coordination are not viable options. first, being large, being influential, being available or simply being useful, are all important factors for adaptation. Being control is not an option this environment since no is actually control. Rosado and Castelo (2008) use the term “shadow IT” for systems built without central corporate approval. These systems are built because centrally controlled IT architectures are not deployed fast enough to solve real problems at the edge of the organization. Conflicts often arise between central IT departments (who want to centralize) and the sub-departments deploying these edge applications. Rosado and Castelo argue that shadow IT can fact drive innovation and effectiveness, and that shadow and central IT may both be leveraged to achieve an effective, agile IT environment.