This 2nd volume on Emerging Web Services Technologies continues to follow the
current research activities in the areas of Web Services and Service Oriented Architectures.
By collecting the proceedings of the second Workshop of Emerging
Web Services Technology 2007 it contains many examples of promising research
activities cutting across a growing set of emerging technologies: service discovery
and selection, service composition, extensions to BPEL, security, quality of service
resource brokering and performance evaluation.
Part I opens the proceedings with an extended abstract outlining some of the
research challenges ahead as presented in the very well received keynote given by
Part II continues this book with three chapters on service discovery and selection.
The first chapter by Baldoni, Baroglio, Martelli, Patti, and Schifanella
presents a novel approach to service discovery that goes beyond selection based on
operation semantics matching by taking into account the context of the lookup as
given by the choreography to which the service needs to conform. The second chapter
by Stein, Barchewitz, and El Kharbili takes a look at the problem of service
discovery from the perspective of business experts using the ARIS process modeling
tool. The chapter gives a concrete example on how structural and semantics
matching techniques are starting to make an impact in industrial applications and
tools. The third chapter by Ku¨ster, Lausen, and Ko¨nig-Ries concludes this part
by giving a thorough evaluation of current semantic service discovery efforts and
outlining several important future research challenges.
Part III covers service composition from three different perspectives. The first
chapter by L´ecue, Silva, and Pires presents the SPICE framework for dynamic
Web service composition. Services are chained taking into account their functional
description in terms of input, output, preconditions and effects as well as nonfunctional
properties. This results in a graph of semantic connections between
the services. The second chapter by Lau and Tran contributes a novel component
model tailored to recursive Web service composition. The third chapter by Charfi,
Berbner, Mezini, and Steinmetz gives an in-depth discussion of requirements for
the management of run-time aspects of Web service composition engines.
Part IV contains two extensions of the Business Process Execution Language
(BPEL) standard. The first chapter by Habich, Richly, Preissler, Lehner, Grasselt,
and Maier is about strenghtening BPEL to support data intensive applications.
To supplement the existing ’by value’ semantics, the authors introduce a new kind
of data transition amenable to performance optimizations. The second chapter
by Overdick foresees the application of BPEL to model the state of a RESTful
Web services and proposes the necessary language extensions to deal with the
identification and the uniform interface of resources.