Professor Michael N. Huhns
Department of Computer Science and Engineering
Swearingen Engineering Center
University of South Carolina
Columbia, SC 29208
Email: huhns@sc.edu
Office: Swearingen 3A41
Phone: +1 (803) 777-5921 +1 (803) 777-5921
Fax: +1 (803) 777-3767
Dr. Michael N. Huhns is the NCR Professor of Computer Science and Engineering and director of the Center for Information Technology at the University of South Carolina. His degrees in electrical engineering are from the University of Michigan (B.S.) and the University of Southern California (M.S. and Ph.D.). He is the author of eight books and more than 200 papers in multiagent systems, service-oriented computing, and ontologies. With Munindar Singh, he coauthored the textbook Service-Oriented Computing: Semantics, Processes, Agents [Wiley 2005]. He serves on the editorial boards for 12 journals and is a founding member of the International Foundation for Autonomous Agents and Multiagent Systems, a Senior Member of the ACM, and a Fellow of the IEEE.
Web Services: Promise, Reality, and Potential
The original objective for Web services was to further the realization of the Semantic Web by revolutionizing the development of distributed software applications across enterprise boundaries. Although the use of Web services across enterprises has not been widespread, the use of Web services in static service-oriented architecture (SOA)-based systems has been successful in many application domains. That is, the use of dynamically discovered, configured, deployed, engaged, and maintained services has not been successful. The problem is that current service standards, which are necessary for widespread usage of services, are unable to describe anything other than the simple syntax and formatting of service invocations; they are thus insufficient for characterizing the rich usage and interactions required throughout the lifetimes of service-based applications. Moreover, service-based architectures will need to become more flexible and accommodate peer-to-peer interactions, as well as client-server interactions.
The Web has been successful largely because its founding principles and protocols are simple and minimal. When uncertainties arise, they are overcome by relatively simple indexing, ranking, and redundancy. None of these techniques has been exploitable for services. In addition, the simplicity of services applies only to their structure, and not to their function and behavior, which have mostly been ignored in Web service engineering.
Agent-based Web services exacerbate the problems, while–surprisingly–also providing the only reasonable solutions to them. The autonomy of agent-based services makes them less predictable, but also enables them to self recover and to avoid deadlocks and livelocks, thereby making them more reliable. Their ability to learn can increase their robustness by being able to adapt to changing interaction environments, but also can increase their unpredictability. Their abilities to negotiate and reconcile semantics can enable them to reestablish connections and relationships among services and ameliorate uncertain execution environments. The peer-to-peer interactions of agents can improve the efficiency of agent-based services, particularly when they are deployed in clouds. Finally, agents can exploit redundancy.