Service Discovery (cancelled)

Service oriented architectures facilitate loose coupling of services, which means that services are invoked in a dynamic way. A major aspect of this loose coupling is searching and finding relevant services, also known as service discovery. The main challenge is to determine services, which provide the expected and required properties like Quality of Service, semantics of the service, and execution sequences of operations (workflows). This tutorial outlines the generic options of setting up complex systems based on service oriented architectures, discusses potential options of finding services as a basis for such complex systems, and elaborates on the scalability of service discovery infrastructures. In particular, the tutorial describes specific characteristics of service oriented architectures and different options of service composition to implement systems involving several service providers. Thus, a classification based on the different ways of doing service composition with regard to the allowed dependencies between different service providers is outlined. Further, in the tutorial we focus on service discovery as an essential aspect of service composition. Since service discovery is the comparison of the description of a service request with a description of a service offering, the tutorial gives on overview of different dimensions of service description as well as corresponding comparison operations. Finally, in the tutorial we focus on one particular aspect of service description: the workflow aspect representing the execution sequences of a service. A proposal of describing the workflow aspects of services and a related comparison operation is presented. This example is used to illustrate the effects of the usually complex comparison operations on the scalability of the service discovery infrastructure.

Organization

The tutorial is a half-day activity co-located with ECOWS 2005. It will be held on 13:30 - 17:00 on Monday 14 November 2005 (to be confirmed).

For registration please enter the ECOWS registration procedure.

For further organizational information, e.g. regarding material and schedule, please contact the organizers directly.

Organizer / Presenters

Andreas Wombacher
University of Twente, NL
E-mail: a.wombacher@utwente.nl

Learning Objectives

The attending audience will get an overview on the following topics:

brief summary of SOA specifica
overview of service discovery and the corresponding challenges
service description as the basis for service discovery - the tutorial addesses interface, semantics, quality of service, and behavioral (workflow) aspects
the implications of the service description on the service discovery are discussed covering the above mentioned aspects again
a more detailed discussion on the workflow aspects follows where the challenges are illustrates in more detail; that is, the discovery in the bilateral vs. multi-lateral case, the static change management, and the scalability issue
a discussion of current directions in service discovery research and its exploitation potential in industry

Target Audience

The tutorial addresses technical people being familiar with basic concepts of service oriented architectures / web services and being interested in a deeper insight into service discovery and its issues.

Short Bio of presenters

Andreas Wombacher is a postdoc researcher at University of Twente. He received his Master degree from the Technical University Darmstadt, Germany. He has worked at IBM for two years on electronic commerce systems before he joined Fraunhofer Gesellschaft (FHG). The next six years he worked at FHG, where his research interests include cross-organizational workflows, decentralization of data and processes, and Web Services. In 2004 he joined University of Twente working on security and trust in cross-organizational workflows. He gathered experience in several European funded projects in the area of business to business data integration and workflows crossing boundaries. He is involved in several organization committees and serves in the editorial review board of International Journals. Further, he has published in several international conferences and journals.