Supporting distributed autonomous information services using coordination

The large quantity and often questionable quality of available information in the information age provides a shaky foundation for decision making by i ndividuals and organizations alike. This has created a tremendous demand fo r information services which can access, filter, process and present inform ation on an as-needed basis. However, two factors complicate the design of such information services, namely the distributed and the autonomous nature of data sources. This paper reports on the design and implementation of a generic architectu re for supporting information services, which meets the above challenge. Th e architecture adopts concepts from conceptual modeling to offer a transpar ent description of the information sources' setting and uses active databas es techniques to offer a declarative, event-based language for defining coo rdination rules for integrating distributed information services. According ly, the proposed architecture supports two of the most prominent utilities of information services, namely the pre-designed how of operations and the reactive provision of information. In addition to describing the architecture and illustrating its features wi th an example, the paper presents a prototype implementation and reports on some experimental performance results.