Web Service Registry Research Articles

Unified publication and discovery of semantic Web services

The challenge of publishing and discovering Web services has recently received lots of attention. Various solutions to this problem have been proposed which, apart from their offered advantages, suffer the following disadvantages: (i) most of them are syntactic-based, leading to poor precision and recall, (ii) they are not scalable to large numbers of services, and (iii) they are incompatible, thus yielding in cumbersome service publication and discovery. This article presents the principles, the functionality, and the design of PYRAMID-S which addresses these disadvantages by providing a scalable framework for unified publication and discovery of semantically enhanced services over heterogeneous registries. PYRAMID-S uses a hybrid peer-to-peer topology to organize Web service registries based on domains. In such a topology, each Registry retains its autonomy, meaning that it can use the publication and discovery mechanisms as well as the ontology of its choice. The viability of this approach is demonstrated through the implementation and experimental analysis of a prototype.

An active registry for bioinformatics web services

Summary: The EMBRACE Registry is a web portal that collects and monitors web services according to test scripts provided by the their administrators. Users are able to search for, rank and annotate services, enabling them to select the most appropriate working service for inclusion in their bioinformatics analysis tasks.Availability and implementation: Web site implemented with PHP, Python, MySQL and Apache, with all major browsers supported. (www.embraceregistry.net)Contact: steve.pettifer@manchester.ac.uk

BioCatalogue: A Curated Web Service Registry For The Life Science Community

AbstractWeb Services have gained a momentum as a means for packaging existing data and computational resources in a form that is amenable for use and composition by third party applications. The life science community is certainly among the first adopters of Web Services. For example, "Taverna":http://www.mygrid.org.uk, a workflow workbench that is popular within the life science community, provides access to over 3500 thousands web services that can be composed by scientists for constructing and enacting their in silico experiments. However, one of the main issues that hinders the wide adoption and use of Web Services is the difficulty in locating the “appropriate” Web Service, i.e., the Web Service that performs the analysis the scientist is interested in. The descriptions of available Web Services are often poor providing little information to the scientist about their usefulness for the analysis s/he is after. With the above issues in mind, the authors have recently initiated the BioCatalogue project ("http://www.biocatalogue.org/":http://www.biocatalogue.org/). BioCatalogue provides a central registry of curated biological Web Services. A place where providers, users and expert curators can register, annotate and search for Web Services. It also acts as a place where the community can contact and meet the experts and maintainers of these services. The project is co-developed by the University of Manchester and the EMBL-EBI.

BioCatalogue: A Curated Web Service Registry For The Life Science Community

Web services have gained a momentum as a means for packaging existing data and computational resources in a form that is amenable for use and composition by third party applications. They provide a well defined programming interface to integrate tools into applications over networks. Software applications written in various programming languages and running on various platforms can use web services to exchange data over the Internet. The life science community is certainly among the first adopters of web services.

A Semantic Web service-oriented application for mobility impaired users

This paper presents a service-oriented application whose purpose is to assist various activities of mobility impaired people as they move from one location to another. Such activities include trip planning, route guidance, e-working, e-learning, search for points of interest and social events among others. A number of registered web services provide all the required content and information that are displayed on the end-user device. Existing services are marked up by a number of domain ontologies about the information needs of mobility impaired users, in order to enable ontology-based search and retrieval of services. A service alignment tool has been developed to facilitate the markup process on behalf of service providers. After describing the architecture of the overall application and the involved mechanisms, we demonstrate a number of use cases that are enabled by the presented technologies.

Active Web Service Registries

Atom news feeds can work both as an infrastructure for distributed Web service registries and to inform users about Web service changes. The authors consider an approach in which every Web service provider offers a Web service registry news channel that serves as part of a globally distributed registry. They also apply this approach to a real-world case study. Their future plans include providing a Web service aggregator that offers additional metadata for Web service descriptions, which users could generate as they rate the services they use.

PpXML: A generic and extensible language for lifecycle modelling of platform products

This paper presents a new language, ppXML (platform product eXtensible Markup Language), for the lifecycle modelling of platform products in agile product development for mass customization (MC). ppXML has multi-folded meanings. Firstly, ppXML provides a set of constructs that are consistent with concepts and methods widely used in platform product development (PPD) for MC. Secondly, derived from XML as a sublanguage, ppXML is a standard and yet extensible modelling language dedicated to the modelling of product variants and platforms reflecting commonality, modularity, scalability and other strategies. Thirdly, ppXML can also be extended for defining web services deployed in the computation grid of web-based decision support systems (DSS) for platform product development and mass customization. Finally, ppXML serves as a standard interface with the product platform repository and a PPD web service registry, together with a set of online facilities for data representation and transformation between different components and parties involved in the web services. ppXML complements the efforts in product lifecycle data modelling by emphasizing the strategic level of product planning using a platform approach.

Plug‐and‐play remote portlet publishing

AbstractWeb Services for Remote Portlets (WSRP) is gaining attention among portal developers and vendors to enable easy development, increased richness in functionality, pluggability, and flexibility of deployment. Whilst currently not supporting all WSRP functionalities, open‐source portal frameworks could in future use WSRP Consumers to access remote portlets found from a WSRP Producer registry service. This implies that we need a central registry for the remote portlets and a more expressive WSRP Consumer interface to implement the remote portlet functions. This paper reports on an investigation into a new system architecture, which includes a Web Services repository, registry, and client interface. The Web Services repository holds portlets as remote resource producers. A new data structure for expressing remote portlets is found and published by populating a Universal Description, Discovery and Integration (UDDI) registry. A remote portlet publish and search engine for UDDI has also been developed. Finally, a remote portlet client interface was developed as a Web application. The client interface supports remote portlet features, as well as window status and mode functions. Copyright © 2007 John Wiley & Sons, Ltd.

Constraint-based brokering (CBB) for publishing and discovery of web services

Much effort is being made by the IT industry towards the development of a Web Service infrastructure to enable the discovery and sharing of heterogeneous applications and data resources. The existing implementation of Web Service registries does not have constraint specification and processing capabilities to achieve intelligent service discovery. In this work, we have extended the Web Service Description Language to allow service providers to specify their service constraints, and developed a Constraint-based Web Service Broker capable of matching a service requestor's requirement specification against providers' constraints to find their desired services. This paper presents the extended Web Service Description Language, the architecture and implementation of the Broker, the constraint matching technique, and the result of a performance evaluation.

Gbrowse Moby: a Web-based browser for BioMoby Services

BackgroundThe BioMoby project aims to identify and deploy standards and conventions that aid in the discovery, execution, and pipelining of distributed bioinformatics Web Services. As of August, 2006, approximately 680 bioinformatics resources were available through the BioMoby interoperability platform. There are a variety of clients that can interact with BioMoby-style services. Here we describe a Web-based browser-style client – Gbrowse Moby – that allows users to discover and "surf" from one bioinformatics service to the next using a semantically-aided browsing interface.ResultsGbrowse Moby is a low-throughput, exploratory tool specifically aimed at non-informaticians. It provides a straightforward, minimal interface that enables a researcher to query the BioMoby Central web service registry for data retrieval or analytical tools of interest, and then select and execute their chosen tool with a single mouse-click. The data is preserved at each step, thus allowing the researcher to manually "click" the data from one service to the next, with the Gbrowse Moby application managing all data formatting and interface interpretation on their behalf. The path of manual exploration is preserved and can be downloaded for import into automated, high-throughput tools such as Taverna. Gbrowse Moby also includes a robust data rendering system to ensure that all new data-types that appear in the BioMoby registry can be properly displayed in the Web interface.ConclusionGbrowse Moby is a robust, yet facile entry point for both newcomers to the BioMoby interoperability project who wish to manually explore what is known about their data of interest, as well as experienced users who wish to observe the functionality of their analytical workflows prior to running them in a high-throughput environment.

Integration of transient Web services into a virtual peer to peer Web service registry

Transient Web service provisioning implies a variety of different requirements that are hard to meet in traditional Web service environments. Currently, Web service brokerage focuses on centralized or replicated architectures. We argue that such systems are not efficient when it comes to dynamic, respectively ad hoc, Web service provisioning. We propose a distributed peer to peer Web service registry solution based on lightweight Web service profiles. We further introduce the notion of views that allow the specification of arbitrary contexts of Web services and provide a working example to illustrate our approach. Finally, we present a prototype that uses tuple spaces as global storage and communication means.

An interoperable and scalable Web-based system for classifier sharing and fusion

This paper describes CSF/DC, a Web-based system for classifier sharing and fusion. CSF/DC enables the sharing of classification models, by allowing the upload and download of such models expressed in the industry standard PMML language on the system's online classifier repository. CSF/DC also leverages the individual knowledge shared by such (potentially heterogeneous) classification models and offers quality decision support to any user with an Internet connection through a guided procedure. However, some organizations or individuals might want to share the predictive capabilities of their classification models without compromising their internal structure. This is accommodated by CSF/DC through the use of Web services. Specifically, CSF/DC allows the participation of classifier Web services in the decision fusion process, by offering the necessary online mechanisms for the registration and invocation of such Web services developed and installed at remote sites.

View Based Integration of Heterogeneous Web Service Registries—the Case of VISR

Despite all standardization efforts in the Web service area, several different incompatible Web service registry implementations exist. The initial focus of these implementations was geared towards working with a centralized Universal Business Registry (UBR). However, these centralized approaches tend to be bottlenecks regarding performance and fault tolerance. A proposed solution is the replication of registry information among multiple distributed Web service registries. In addition, the creation of specialized Web service registries leads to a large number of different Web service registries. This leads to a situation where the search for a particular Web service becomes a very complex task. Besides, Web service provisioning includes a considerable administrative overhead when dealing with transient Web services. Transient Web services exist only for a limited lifetime and in a certain context. In this paper, we propose the VISR (View based Integration of Web Service Registries) peer to peer architecture for the transparent integration of multiple Web service registries and transient Web service providers. This work focuses on the integration concept of multiple Web service registries and transient Web service providers. The integration concept relies on so-called views. Views provide the needed abstractions for the seamless integration on the different registries. Views use common lightweight Web service profiles that serve as unified global data model. VISR Web service profiles allow the flexible extension of registry entries with value added information without changing the original Web service registry entries. To illustrate the view concept, we introduce a simple grammar (View Description Language) for view descriptions that is used in the working example throughout the paper. We present Web service communities as a possible application of the view concept and show how different types of Web services providers, respectively, their registries are integrated into a unified global data model.

A Clustering Based Approach for Facilitating Semantic Web Service Discovery

The World Wide Web is transitioning from being a mere collection of documents that contain useful information toward providing a collection of services that perform useful tasks. The emerging Web service technology has been envisioned as the next technological wave and is expected to play an important role in this recent transformation of the Web. By providing interoperable interface standards for application-to-application communication, Web services can be combined with component based software development to promote application interaction and integration both within and across enterprises. To make Web services for service-oriented computing operational, it is important that Web service repositories not only be well-structured but also provide efficient tools for developers to find reusable Web service components that meet their needs. As the potential of Web services for service-oriented computing is being widely recognized, the demand for effective Web service discovery mechanisms is concomitantly growing. A number of techniques for Web service discovery have been proposed, but the discovery challenge has not been satisfactorily addressed. Unfortunately, most existing solutions are either too rudimentary to be useful or too domain dependent to be generalizable. In this paper, we propose a Web service discovery approach that combines clustering techniques with string matching and leverages the semantics of the XML-based service specification in WSDL documents. We believe that this is one of the first attempts at applying data mining techniques in the Web service discovery domain. Our proposed approach has several appealing features: (1) It minimizes the requirement of prior knowledge from both service consumers and publishers; (2) It avoids exploiting domain dependent ontologies; and (3) It is able to visualize the semantic relationships among Web services. We have developed a Web service discovery tool based on the proposed approach using an unsupervised artificial neural network and empirically evaluated the proposed approach and tool using real Web service descriptions drawn from operational Web service registries. We report on some preliminary results demonstrating the efficacy of the proposed approach.

Research and Implementation of an Active Distributed Web Service Registry

In SOA (service oriented architecture), the service registry takes place an important role which complies with UDDI (universal description, discovery and integration) specification. However, some tough problems are still in the way of present UDDI registry. For example, current registry has to replicate all web service publications in all UBR (universal business registry) nodes, and thus becomes impractical for a large number of web services. Furthermore, present UDDI registry is a passive directory and cannot guarantee the real-time validity of the services. In this paper, an active distributed architecture named as adUDDI is proposed for federated web service publication and discovery among multiple registries. With the distributed architecture, the service information is published within one or more adUDDIs so as to avoid the performance bottlenecks in centralized configuration. With the active monitoring mechanism, the service information is updated automatically and then the service requestor may find the latest service information. Finally, comprehensive simulations are evaluated and the results show that it outperforms the existing approaches.

STRUCTURAL AND SEMANTIC MATCHING FOR ASSESSING WEB-SERVICE SIMILARITY

The web-services stack of standards is designed to support the reuse and interoperation of software components on the web. A critical step in the process of developing applications based on web services is service discovery, i.e. the identification of existing web services that can potentially be used in the context of a new web application. Discovery through catalog-style browsing (such as supported currently by web-service registries) is clearly insufficient. To support programmatic service discovery, we have developed a suite of methods that assess the similarity between two WSDL (Web Service Description Language) specifications based on the structure of their data types and operations and the semantics of their natural language descriptions and identifiers. Given only a textual description of the desired service, a semantic information-retrieval method can be used to identify and order the most relevant WSDL specifications based on the similarity of the element descriptions of the available specifications with the query. If a (potentially partial) specification of the desired service behavior is also available, this set of likely candidates can be further refined by a semantic structure-matching step, assessing the structural similarity of the desired vs the retrieved services and the semantic similarity of their identifiers. In this paper, we describe and experimentally evaluate our suite of service-similarity assessment methods.

Extensible soft semantic web services agent

Web services technology is critical for the success of business integration and other application fields such as bioinformatics. However, there are two challenges facing the practicality of Web services: (a) efficient location of the Web service registries that contain the requested Web services and (b) efficient retrieval of the requested services from these registries with high quality of service (QoS). The main reason for this problem is that current Web services technology is not semantic-oriented. Several proposals have been made to add semantics to Web services to facilitate discovery and composition of relevant Web services. Such proposals are being referred to as semantic Web services (SWS). However, most of these proposals do not address the second problem of retrieval of web services with high QoS. In this paper, we propose a framework called soft semantic Web services agent (soft SWS agent) for providing high QoS Semantic Web services using soft computing methodology. Since different application domains have different requirement for QoS, it is impractical to use classical mathematical modeling methods to evaluate the QoS of semantic Web services. We use fuzzy neural networks with Genetic Algorithms (GA) as our study case. Simulation results show that the soft computing methodology is practicable to handle fuzzy and uncertain QoS metrics effectively.

A View Based Analysis on Web Service Registries

Web services registries are a cornerstone for the emerging service-oriented architecture and constitute a critical resource for Web services. We systematically illustrate and evaluate current registries and compare different approaches regarding their architectures and data models in the context of two views: the human and Web service based views. We use these views to show the different requirements and to illustrate the different abstractions when comparing Web service registries. The human view on Web service registry architectures is illustrated with the help of a case study. The Web service view on Web services registry architectures is illustrated from a software-service point of view. The data model of Web service registries is described in detail from a machine based view. The corresponding human view is described from an abstract level. Web service publishing and discovery are compared from a human and a Web service based view. Finally, we present a working example that uses our methodology to compare different Web service registries and to explain the different views introduced in this paper.

Web Service Composition Using a Deductive XML Rule Language

This paper describes a knowledge-based Web Service composition system, called SWIM, which is based on the Service Domain model. Service Domains are communities of related Web Services that are mediated by a single Web Service, called the Mediator Service, which functions as a proxy for them. When a requestor sends a message to the Mediator Service one or more of the related Web Services are selected to dispatch the message and the results returned are aggregated to a single answer to the requestor. Mediator Services can be further composed to more complex Mediator Services that combine several selection and aggregation algorithms among many heterogeneous web services. The system utilizes the X-DEVICE deductive XML rule language for defining complex algorithms for selecting registered web services, combining the results, and synchronizing the workflow of information among the combined web services in a declarative way. In the paper, we demonstrate the flexibility and expressibility of our approach for composing Web Services using several e-business examples, covering most of the workflow patterns found in a comprehensive workflow management system (van der Aalst et al., Distributed and Parallel Databases, vol. 14, no, 1, pp. 5-15, 2003).

Web services lookup: a matchmaker experiment

UDDI is a standard registry for Web services, but so far its search functionality has been limited to keyword search. These authors propose a UDDI enhancement called Matchmaker, which supports semantic service capability discovery. Since September 2003, they have deployed Matchmaker in one of four official UDDI registries operated by NTT-Communications. In this article, they introduce Matchmaker and illustrate client tools that lower the threshold for using semantics in service discovery. Experiments show that Matchmaker search consumes about 5 seconds more time than a typical keyword-based search. The authors also collected user information through questionnaires and by observation of search behavior.