JWSR, Volume 1, Number 3, July-September 2004
Official Publication of the Information Resources Management Association
Published: Quarterly in Print and Electronically
ISSN: 1545-7362
EISSN: 1546-5004


EDITORIAL PREFACE:

"Convergence of Web Services and Grid Computing"

Liang-Jie Zhang, IBM T.J. Watson Research Center, USA
Mario Jeckle, University of Applied Sciences, Furtwangen, Germany

This issue of the International Journal of Web Services Research (JWSR) collects a number of re-worked and enhanced high quality papers which were reviewed for the International Conference on Web Services Europe 2003 (ICWS-EU’03) held in Erfurt Germany from September 22-25 in conjunction with the Net.ObjectDays conference.

RESEARCH PAPERS

PAPER ONE:

"Adaptation Space: A Design Framework for Adaptive Web Services"

Paques, H.
Liu, L.
Pu, C.

Web service adaptation is an important feature for mission critical Web services. It is widely recognized that thrashing and crashes occur in system saturation for many statically adaptive resource management algorithms, including CPU, memory, and network congestion. Service adaptation supports alternative responses to saturation control, maintaining service and server system stability and progress, instead of thrashing. In this article, we present a design framework for developing adaptive Web services. The core of this framework is the adaptation space model, which is based on the concepts of adaptation space and adaptation case. An adaptation space is defined by a reference context and a partial order of adaptation cases. Each adaptation case describes a specific adaptation of a program or component of a Web service. We evaluate the adaptation space approach using Ginga, an adaptive query processing service for handling queries over multiple data sources with diverse capabilities across the Internet. Our experimental results show that Ginga query adaptation can achieve significant performance improvements (up to 40% of response time gain) for processing distributed queries over the Internet in the presence of end-to-end delays.

To obtain a copy of the entire article, click on the link below.
http://www.igi-pub.com/articles/details.asp?ID=4445

PAPER TWO:

"AOP for Dynamic Configuration and Management of Web Services"

Verheecke, B.
Cibran, M.A.
Vanderperren, W.
Suvee, D.
Jonckers, V.

We observe that current approaches for the integration of Web services hard-wire the service references into client applications, affecting adaptability and reusability. Moreover, support for client-side management is hardly provided. To enable the development of more flexible and robust applications we propose the Web Services Management Layer (WSML). In this article we identify the requirements for the WSML to realize dynamic integration, client-side service management, and support for service criteria to govern the selection, integration and composition of Web services. We show how dynamic AOP, and in particular the dynamic aspect-oriented language JAsCo, is ideally suited to implement the core functionality of the WSML.

To obtain a copy of the entire article, click on the link below.
http://www.igi-pub.com/articles/details.asp?ID=4446

PAPER THREE:

"Pattern-Based Design of an Asynchronous Invocation Framework for Web Services"

Zdun, U.
Voelter, M.
Kircher, M.

Asynchronous invocations are needed in the context of distributed object frameworks to prevent clients from blocking during remote invocations. Popular Web service frameworks offer only synchronous invocations (over HTTP). An alternative is messaging protocols but these implement a different communication paradigm. When client asynchrony is not supported, client developers have to build asynchronous invocations on top of the synchronous invocation facility. But this is tedious, error-prone, and might result in different remote invocation styles used within the same application. We present a number of patterns for asynchronous invocations and explain how these patterns can be used to build asynchronous invocation facilities for Web service frameworks. We exemplify this approach by explaining the design and implementation of an asynchronous invocation framework for Apache Axis.

To obtain a copy of the entire article, click on the link below.
http://www.igi-pub.com/articles/details.asp?ID=4447

PAPER FOUR:

"Towards a Framework for Agent-Enabled Semantic Web Service Composition"

Ermolayev, V.
Keberle, N.
Plaksin, S.
Kononenko, O.
Terziyan, V.

The article presents the framework for agent-enabled dynamic Web service composition. The core of the methodology is the new understanding of a Web service as an agent capability having proper ontological description. It is demonstrated how diverse Web services may be composed and mediated by dynamic coalitions of software agents collaboratively performing tasks for service requestors. Middle Agent Layer is introduced to conduct service request to task transformation, agent-enabled cooperative task decomposition and performance. Discussed are the formal means to arrange agents?negotiation, to represent the semantic structure of the task-activity-service hierarchy and to assess fellow-agents?capabilities and credibility factors. Finally, it is argued that the presented formal technique is applicable to various application domains. Presented is the ongoing work on designing and implementing agent-based layered architecture for intelligent rational information and document retrieval. Finally, the discussion of the OntoServ.Net framework for the development of P2P mobile service infrastructures for industrial asset management provides the extension of the Web service composition approach.

To obtain a copy of the entire article, click on the link below.
http://www.igi-pub.com/articles/details.asp?ID=4448

PAPER FIVE:

"Seamlessly Securing Web Services by a Signing Proxy"

Jeckle, M.
Melzer, I.

Web services offer a way for very different systems to collaborate independent of the programming language used or the involved operating systems. Their basis is the XML-based SOAP protocol, which can be used over any protocol that is able to transport a byte stream. Due to the fact that Web services do not depend on any operating system and there is no burden of a underlying paradigm, they are ideal for the integration of even completely inhomogeneous systems. However, SOAP does not (and does not have to) deal with security issues, which is nevertheless important for the involved systems. This article describes an add-on for existing Internet proxies to achieve user and developer transparent security features for Web services. This approach allows corporate firewalls to handle authentication. A first step is to add corporate signatures to all outgoing SOAP messages to enable a corporate trust relationship. A second improvement is to use proxy authentication as defined in RFC 2616 and RFC 2617 to add personal signatures assuming that the proxy has access to some key management system.

To obtain a copy of the entire article, click on the link below.
http://www.igi-pub.com/articles/details.asp?ID=4449

*****************************************************
For full copies of the above articles, check for this issue of the International Journal of Web Services Research (JWSR) in your Institution's library.
*****************************************************