Showing papers on "WS-I Basic Profile published in 2004"

QoS-aware middleware for Web services composition

Abstract: The paradigmatic shift from a Web of manual interactions to a Web of programmatic interactions driven by Web services is creating unprecedented opportunities for the formation of online business-to-business (B2B) collaborations. In particular, the creation of value-added services by composition of existing ones is gaining a significant momentum. Since many available Web services provide overlapping or identical functionality, albeit with different quality of service (QoS), a choice needs to be made to determine which services are to participate in a given composite service. This paper presents a middleware platform which addresses the issue of selecting Web services for the purpose of their composition in a way that maximizes user satisfaction expressed as utility functions over QoS attributes, while satisfying the constraints set by the user and by the structure of the composite service. Two selection approaches are described and compared: one based on local (task-level) selection of services and the other based on global allocation of tasks to services using integer programming.

Web services agreement specification (ws-agreement)

Abstract: This document describes Web Services Agreement Specification (WS-Agreement), a Web Services protocol for establishing agreement between two parties, such as between a service provider and consumer, using an extensible XML language for specifying the nature of the agreement, and agreement templates to facilitate discovery of compatible agreement parties. The specification consists of three parts which may be used in a composable manner: a schema for specifying an agreement, a schema for specifying an agreement template, and a set of port types and operations for managing agreement life-cycle, including creation, expiration, and monitoring of agreement states. GFD-R-P.107 March 14, 2007 Grid Resource Allocation Agreement Protocol (GRAAP) WG graap-wg@ogf.org 2 Table of

Bringing semantics to web services: the OWL-S approach

Abstract: Service interface description languages such as WSDL, and related standards, are evolving rapidly to provide a foundation for interoperation between Web services. At the same time, Semantic Web service technologies, such as the Ontology Web Language for Services (OWL-S), are developing the means by which services can be given richer semantic specifications. Richer semantics can enable fuller, more flexible automation of service provision and use, and support the construction of more powerful tools and methodologies. Both sets of technologies can benefit from complementary uses and cross-fertilization of ideas. This paper shows how to use OWL-S in conjunction with Web service standards, and explains and illustrates the value added by the semantics expressed in OWL-S.

Similarity search for web services

Abstract: Web services are loosely coupled software components, published, located, and invoked across the web. The growing number of web services available within an organization and on the Web raises a new and challenging search problem: locating desired web services. Traditional keyword search is insufficient in this context: the specific types of queries users require are not captured, the very small text fragments in web services are unsuitable for keyword search, and the underlying structure and semantics of the web services are not exploited. We describe the algorithms underlying the Woogle search engine for web services. Woogle supports similarity search for web services, such as finding similar web-service operations and finding operations that compose with a given one. We describe novel techniques to support these types of searches, and an experimental study on a collection of over 1500 web-service operations that shows the high recall and precision of our algorithms.

Web Services Choreography Description Language Version 1.0, W3C

Abstract: 19 20 21 22 23 24 25 26 27 28 29 30 31 The Web Services Choreography Description Language (WS-CDL) is an XML-based language that describes peer-to-peer collaborations of parties by defining, from a global viewpoint, their common and complementary observable behavior; where ordered message exchanges result in accomplishing a common business goal. The Web Services specifications offer a communication bridge between the heterogeneous computational environments used to develop and host applications. The future of E-Business applications requires the ability to perform long-lived, peer-to-peer collaborations between the participating services, within or across the trusted domains of an organization. The Web Services Choreography specification is targeted for composing interoperable, peer-to-peer collaborations between any type of party regardless of the supporting platform or programming model used by the implementation of the hosting environment.

Meteor-s web service annotation framework

Abstract: The World Wide Web is emerging not only as an infrastructure for data, but also for a broader variety of resources that are increasingly being made available as Web services. Relevant current standards like UDDI, WSDL, and SOAP are in their fledgling years and form the basis of making Web services a workable and broadly adopted technology. However, realizing the fuller scope of the promise of Web services and associated service oriented architecture will requite further technological advances in the areas of service interoperation, service discovery, service composition, and process orchestration. Semantics, especially as supported by the use of ontologies, and related Semantic Web technologies, are likely to provide better qualitative and scalable solutions to these requirements. Just as semantic annotation of data in the Semantic Web is the first critical step to better search, integration and analytics over heterogeneous data, semantic annotation of Web services is an equally critical first step to achieving the above promise. Our approach is to work with existing Web services technologies and combine them with ideas from the Semantic Web to create a better framework for Web service discovery and composition. In this paper we present MWSAF (METEOR-S Web Service Annotation Framework), a framework for semi-automatically marking up Web service descriptions with ontologies. We have developed algorithms to match and annotate WSDL files with relevant ontologies. We use domain ontologies to categorize Web services into domains. An empirical study of our approach is presented to help evaluate its performance.

Web Services Architecture

Abstract: Microsoft has promoted ASP.NET’s new web services more than almost any other part of the.NET Framework. But despite their efforts, confusion is still widespread about what a web service is and, more importantly, what it’s meant to accomplish. This chapter introduces web services and explains their role in Microsoft’s vision of the programmable web. Along the way, you’ll learn about the open standards plumbing that allows web services to work and removes some of the confusion surrounding technical terms like WSDL (Web Service Description Language), SOAP, and UDDI (universal description, discovery, and integration).

Universal Description, Discovery, and Integration

Abstract: Universal Description, Discovery, and Integration (UDDI) is a standardized process to publish and discover information of Web services (as well as other services) programmatically or via a graphical user interface that would typically be Web based. The aim of UDDI is to provide a standard, uniform service, which is readily accessible by applications via a programmatic interface or by people via a graphical user interface (GUI). A UDDI directory—referred to as a registry—is meant to be platform independent and can be readily accessible via a Web browser-based GUI or by applications via published application programming interfaces (APIs). The goal of a UDDI directory is to ensure that enterprises and individuals can quickly, easily, and dynamically locate and make use of services—particularly Web services—that are of interest to them. As with all things related to or inspired by Web services, the UDDI is highly Extensible Markup Language (XML)-centric. The core information model used by the UDDI—irrespective of the kind of service being described—is based on an XML schema.

European Interoperability Framework for Pan-European eGovernment Services

Abstract: Disclaimer Neither the European Commission nor any person acting on its behalf is responsible for the use that might be made of the information contained in this document.

Aspect-oriented web service composition with AO4BPEL

Abstract: Web services have become a universal technology for integration of distributed and heterogeneous applications over the Internet. Many recent proposals such as the Business Process Modeling Language (BPML) and the Business Process Execution Language for Web Services (BPEL4WS) focus on combining existing web services into more sophisticated web services. However, these standards exhibit some limitations regarding modularity and flexibility. In this paper, we advocate an aspect-oriented approach to web service composition and present AO4BPEL, an aspect-oriented extension to BPEL4WS. With aspects, we capture web service composition in a modular way and the composition becomes more open for dynamic change.

Quality of Service for Web Services

Abstract: The World Wide Web is evolving from being a pure information repository to a more functional and service oriented platform thanks to technologies such as Web Services. This technology offers a homogeneous representation of Web elements and the ways they are communicating that make it possible to deal with the inherent structural and behavioural heterogeneities of the Web. A Web service can be seen as an autonomous functional element that is loosely coupled to other Web services and can be discovered and deployed in Web-based applications. Autonomity and loose coupling make Web services a viable light weight complementary componentbased approach for design and development of dynamic distributed systems for more heavy weight solutions such as OMG’s CORBA and Microsoft’ s DCOM. In this paper, we take the position that if Web Services are going to be considered as reusable commercial of-the-shelf (COTS) components, their Quality of Service (QoS) needs to be expressed explicitly and measured independently. More specifically, we present and discuss possible quality aspects that need to be represented and quantified for Web Services.

Authorization and privacy for semantic Web services

Abstract: Web services will soon handle users' private information. They'll need to provide privacy guarantees to prevent this delicate information from ending up in the wrong hands. More generally, Web services will need to reason about their users' policies that specify who can access private information and under what conditions. These requirements are even more stringent for semantic Web services that exploit the semantic Web to automate their discovery and interaction because they must autonomously decide what information to exchange and how. In our previous work, we proposed ontologies for modeling the high-level security requirements and capabilities of Web services and clients.1 This modeling helps to match a client's request with appropriate services-those based on security criteria as well as functional descriptions.

Web service composition in UML

Abstract: As the number of available Web services is steadily increasing, there is a growing interest for reusing basic Web services in new, composite Web services. Several organizations have proposed composition languages (BPML, BPMN, BPEL4WS, BPSS, WSCI), but no winner has been declared so far. This work proposes a method that uses UML Activity models to design Web service compositions, and OMG's Model Driven Architecture (MDA) to generate executable specifications in different composition languages. The method utilizes standard UML constructs with a minimal set of extensions for Web services. An important step in the method is the transformation of WSDL descriptions into UML This information is used to complete the composition models. Another key aspect of the method is its independence of the Web service composition language. The user can thus select his preferred composition language - and execution engine - for realizing the composite Web service. Currently, the method has been implemented to support two executable composition languages BPEL4WS and WorkSCo, with corresponding execution engines. WorkSco is a Web service enabled workflow composition language. The method is illustrated with an example from a crisis management scenario.

Web Services Eventing (WS-Eventing)

Abstract: This specification describes a protocol that allows Web services to subscribe to or accept subscriptions for event notification messages. Composable Architecture By using the XML, SOAP [SOAP 1.1, SOAP 1.2], and WSDL [WSDL 1.1] extensibility models, the Web service specifications (WS-*) are designed to be composed with each other to provide a rich set of tools to provide security in the Web services environment. This specification specifically relies on other Web service specifications to provide secure, reliable, and/or transacted message delivery and to express Web service and client policy.

Generating test cases for web services using data perturbation

Abstract: Web services have the potential to dramatically reduce the complexities and costs of software integration projects. The most obvious and perhaps most significant difference between Web services and traditional applications is that Web services use a common communication infrastructure, XML and SOAP, to communicate through the Internet. The method of communication introduces complexities to the problems of verifying and validating Web services that do not exist in traditional software. This paper presents a new approach to testing Web services based on data perturbation. Existing XML messages are modified based on rules defined on the message grammars, and then used as tests. Data perturbation uses two methods to test Web services: data value perturbation and interaction perturbation. Data value perturbation modifies values according to the data type. Interaction perturbation classifies the communication messages into two categories: RPC communication and data communication. At present, this method is restricted to peer-to-peer interactions. The paper presents preliminary empirical evidence of its usefulness.

Approaches to semantic web services: An overview and comparisons

Abstract: The next Web generation promises to deliver Semantic Web Services (SWS); services that are self-described and amenable to automated discovery, composition and invocation. A prerequisite to this, however, is the emergence and evolution of the Semantic Web, which provides the infrastructure for the semantic interoperability of Web Services. Web Services will be augmented with rich formal descriptions of their capabilities, such that they can be utilized by applications or other services without human assistance or highly con-strained agreements on interfaces or protocols. Thus, Semantic Web Services have the potential to change the way knowledge and business services are consumed and provided on the Web. In this paper, we survey the state of the art of current enabling technologies for Semantic Web Services. In addition, we characterize the infrastructure of Semantic Web Services along three orthogonal dimensions: activities, architecture and service ontology. Further, we examine and contrast three current approaches to SWS according to the proposed dimensions.

Towards context-aware adaptable web services

Abstract: In this paper, we present a context framework that facilitates the development and deployment of context-aware adaptable Web services. Web services are provided with context information about clients that may be utilized to provide a personalized behavior. Context is extensible with new types of information at any time without any changes to the underlying infrastructure. Context processing is done by Web services, context plugins, or context services. Context plugins and context services pre- and post-process Web service messages based on the available contextinformation. Both are essential for automatic context processing and automatic adaption of Web services to new context types without the necessity to adjust the Web services themselves. We implemented the context framework within the ServiceGlobe system, our open and distributed Web service platform.

Engineering Web service - agent integration

Abstract: Web services are fast emerging as the dominant means for connecting remotely executing programs via well established Internet protocols and commonly used machine readable representations. Software agents are now increasingly used in commercial applications to solve complex engineering problems, and these applications often expose or make use of Web services. As such, this paper presents a gateway architecture for connecting software agents and Web services in a transparent manner with fully automatic operation. This gateway allows Web services to invoke agent services and vice versa by translating message encodings and service descriptions between the two technologies. We also address how software agents offer the opportunity to introduce new modalities in the ways Web services are used and manipulated, including redirection, aggregation, integration and administration.

An efficient algorithm for OWL-S based semantic search in UDDI

Abstract: The increasing availability of web services demands for a discovery mechanism to find services that satisfy our requirement. UDDI provides a web wide registry of web services, but its lack of an explicit capability representation and its syntax based search provided produces results that are coarse in nature. We propose to base the discovery mechanism on OWL-S. OWL-S allows us to semantically describe web services in terms of capabilities offered and to perform logic inference to match the capabilities requested with the capabilities offered. We propose OWL-S/UDDI matchmaker that combines the better of two technologies. We also implemented and analyzed its performance.

Efficient Selection and Monitoring of QoS-Aware Web Services with the WS-QoS Framework

Abstract: While the concept of UDDI supports the automatic discovery of services implementing a common public tModel interface, there have been only few attempts to find a standardized form to describe the quality of service (QoS) properties of Web services. We introduce our approach "Web service QoS (WS-QoS)" that enables an efficient, dynamic, and QoS-aware selection and monitoring of Web services. The prototype of our approach is implemented with the .NET technology, including the following components: a WS-QoS Editor for the specification of QoS properties, a WS-QoS Requirement Manager for retrieving QoS requirements specified by client applications, a Web service broker for an efficient and QoS-aware selection of Web service offers, and a WS-QoS Monitor for checking the compliance of the service offers.

Interoperability among independently evolving web services

Abstract: The increasing popularity of XML Web services motivates us to examine if it is feasible to substitute one vendor service for another when using a Web-based application, assuming that these services are "derived from" a common base. If such substitution were possible, end users could use the same application with a variety of back-end vendor services, and the vendors themselves could compete on price, quality, availability, etc. Interoperability with substituted services is non-trivial, however, and four types of incompatibilities may arise during such interoperation -- structural, value, encoding and semantic. We address these incompatibilities three-fold: (1) static and dynamic analysis tools to infer whether an application is compatible with a substituted service, (2) semi-automatically generated middleware components called cross-stubs that actually resolve incompatibilities and enable interoperation with substituted services, and (3) a lightweight mechanism called multi-option types to enable applications to be written from the ground up in an interoperation-friendly manner. Using real applications and services as examples, we both demonstrate and evaluate our tools and techniques for enabling interoperation with substituted services.

Enhancing web services description and discovery to facilitate composition

Abstract: Web services are in the midst of making the transition from being a promising technology to being widely used in the industry. However, most efforts to use Web services have been manual, thus slowing down the ever changing and dynamic businesses of today. In this paper, we contend that more expressive descriptions of Web services will lead to greater automation and thus provide more agility to businesses. We present the METEOR-S front-end tools for source code annotation and semantic Web service description generation. We also present WSDL-S, a language created for incorporating semantic descriptions in the industry wide accepted WSDL, by extending WSDL 2.0.

Ontology-driven Web services composition platform

Abstract: Discovering and assembling individual Web services into more complex yet new and more useful Web processes is an important challenge. In this paper, we present techniques for (semi) automatically composing Web services into Web processes by using their ontological descriptions and relationships to other services. In interface-matching automatic composition technique, the possible compositions are obtained by checking semantic similarities between interfaces of individual services. Then these compositions are ranked and an optimum composition is selected. In Human-Assisted composition the user selects a service from a ranked list at certain stages. We also address automatic compositions in a peer-to-peer network.

WS-Negotiation: an overview of research issues

Abstract: A Web service is defined as an autonomous unit of application logic that provides either some business functionality or information to other applications through an Internet connection. Web services are based on a set of XML standards such as Simple Object Access Protocol (SOAP), Universal Description, Discovery and Integration (UDDI) and Web Services Description Language (WSDL). In particular, Web services discovery is the process of finding most appropriate Web services providers needed by a Web services requestor. One of the important issues in the discovery process is for Web services providers and Web services requestors to negotiate and find a solution that is acceptable to both sides. Thus, a more sophisticated business model with negotiation feature is required for this challenging research area. As there are increasing demands for negotiation technologies in the context of Web services, this paper proposes an independent declarative XML language called WS-Negotiation for Web services providers and requestors. In general, WS-Negotiation contains three parts: negotiation message, which describes the format for messages exchanged among negotiation parties, negotiation protocol, which describes the mechanism and rules that negotiation parties should follow, and negotiation decision making, which is an internal and private decision process based on a cost-benefit model or other strategies. This paper also presents a service level agreement (SLA) template model with different domain specific vocabularies for supporting different types of business negotiations in WS-Negotiation.

Model-Driven Web Service Development

Abstract: Web services are emerging as a promising technology for the effective automation of inter-organizational interactions. However, despite the growing interest, several issues still need to be addressed to provide Web services with benefits similar to what traditional middleware brings to intra-organizational application integration. In this paper, we present a framework that supports the model-driven development of Web services. Specifically, we show how, starting from the external specifications of a Web service (e.g., interface and protocol specifications), we can support the generation of extensible service implementation templates as well as of complete (executable) service specifications, thereby considerably simplifying the service development work.

Applying semantic web services to bioinformatics: experiences gained, lessons learnt

Abstract: We have seen an increasing amount of interest in the application of Semantic Web technologies to Web services. The aim is to support automated discovery and composition of the services allowing seamless and transparent interoperability. In this paper we discuss three projects that are applying such technologies to bioinformatics: Grid, MOBY-Services and Semantic-MOBY. Through an examination of the differences and similarities between the solutions produced, we highlight some of the practical difficulties in developing Semantic Web services and suggest that the experiences with these projects have implications for the development of Semantic Web services as a whole.