International Journal of Scientific and Research Publications, Volume 3, Issue 7, July 2013 1 ISSN 2250-3153 www.ijsrp.org Aspect based Enhanced Web Service Discovery Vandan Tewari * , Nirmal Dagdee ** , Aruna Tiwari *** * C.T.A. Dept., Shri G.S.Institute of Tech. & Sc. Indore ** Computer Engg. Dept, S.D. Bansal College of Tech.,Indore *** Comp.Sc. & Engg.,IIT,Indore Abstract- Web services [1] are the latest paradigm of distributed systems which are implemented as typically application programming interfaces (API) or web APIs that are accessed via HTTP and executed on a remote system hosting the requested services. The Web services are used to interact between components, programs, and applications. In this paper, we have proposed an approach to allow for support of web service descriptions and queries using registries that conforms to UDDI V3.0.2 specification. Specifically, our main aim is to discover user requested services based on not only on functional parameters but also non functional parameters such as Quality of Service (QoS) parameters. Web Service discovery can be augmented using query expansion as well as appended with QoS in requirement. Since the metadata associated with web services is very less as compared to HTML pages, to offer a web service appropriate to a client we have used two techniques from Information Retrieval: Query Expansion and Query Rewriting. The proposed approach does not require any modification to the existing UDDI data structures. The add-on modules for searching reside at the service requestor‟s end who wishes to take advantage of better web service discovery. This approach is completely backward compatible and can integrate seamlessly into existing infrastructure. An e-learning technique has been used to demonstrate the effectiveness of proposed approach. Index Terms- Web Services, Discovery, Query Expansion, Quality of Service (QoS) I. INTRODUCTION he service oriented architecture SOA is the latest and most popular realization for web services. Web Services are building blocks of SOA and makes the e-business processes interoperable and loosely coupled. These characteristics makes web services very popular. The basic SOA contains three entities, Service Providers which provide or deploy the services to be used by Service Requestors and Service Brokers which acts as directory services for discovering web services. The Service Broker can be realized as a UDDI Registry. The following is an explanation of underlying technology for deploying , discovering and invoking web services. An E-Learning domain has been chosen to presented for the proposal and therefore an elementary discussion on E-Learning System has also been presented here. Universal Description, Discovery, and Integration (UDDI)[2] The Universal Description, Discovery, and Integration UDDI is a realization of service broker which provides a standard method for publishing and discovering web services. The UDDI is an industry standard that has been developed as a platform- independent, open framework for describing services, discovering businesses, and integrating business services. UDDI is a de facto standard for the process of discovery in the service- oriented architecture. The basic information model and interaction framework of UDDI registries consists of the following data structures[2]: businessEntity: Contains information about the business or organization that is offering the published service. businessService: Contains information about the individual service offered by a business. BindingTemplate:Has information about technical details of as ervice and a reference to the service‟s programmatic interface or API. tModel :Additional information such as categorization metadata, taxonomies and policies, are stored in tModels Fig 1 Basic Data structure of UDDI Extensible Markup Language (XML) XML[3] is widely known paradigm for exchanging information over the web and follows the semi structured model for a rapidly growing number of software development activities. XML is intended as a markup-language for arbitrary document structure, as opposed to HTML, which is a markup language for a specific kind of hypertext documents. E-Learning Systems: E-Learning [4] is the use of Technology to enable people to learn ubiquitously. E- Learning can include training, the delivery of learning content management and information and guidance from experts. Publishing Services for an E-Learning system A Service Provider starts by modeling the real-world concepts associated with the service and creates a WSDL[5] Documentto define the Service's syntax by specifying the structure of the input and output messages, along with aspects of the service's runtime bindings.It then mapselements of WSDL Messages to T