Facilitating dynamic web service composition with fine-granularity context management

Context is an important factor for the success of dynamic service composition. Although many contextbased AI or workflow approaches have been proposed to support dynamic service composition, there is still an unaddressed issue of the support of fine-granularity context management. In this paper, we propose a granularity-based context model together with an approach to supporting the intelligent context-aware service composing problem. The corresponding case study is provided to show the validity of our approach.

Attributed publication and selection for web service-based distributed systems

With the emergence of cloud computing, the need for flexible and detailed publication and selection of services that expose cloud resources is greatly stressed. While dynamic attributes have improved the publication and selection of resources in distributed systems, the use of dynamic attributes is yet to be tried in Web services: a key element that makes cloud computing possible. We propose a new approach to Web service publication and selection using dynamic attributes shown in Web service WSDL documents, the most commonly accessed and used elements of Web services.

CARSA : A context-aware reasoning-based service agent model for AI planning of web service compostion

In order to achieve automatic and more intelligent service composition, dynamic description logic (DDL) is proposed and utilized as one emerging logic-level solution. However, reasoning optimization and utilization in such DDL-related solutions is still an open problem. In this paper, we propose the context-aware reasoning-based service agent model (CARSA) which exploits the relationships among different service consumers and providers, together with the corresponding optimization approach to strengthen the effectiveness of Web service composition. Through the model, two reasoning optimization methods are proposed based on the substitute relationship and the dependency relationship, respectively, so irrelevant actions can be filtered out of the reasoning space before the DDL reasoning process is carried out. The case study and experimental analysis demonstrates the capability of the proposed approach.

A policy-based web service redundancy detection in wireless sensor networks

Wireless sensor networks (WSNs) are attractive for monitoring and gathering physical information (e.g. temperature) via lots of deployed sensors. For the applications in WSNs, Web service is one of the recommended frameworks to publish, invoke, and manage services. However, the standard Web service description language (WSDL), defines only the service input and output while ignoring the corresponding input-to-output mapping relationships. This presents a serious challenge in distinguishing services with similar input and output interface. In this paper, we address this challenge by embedding the service policy into the traditional WSDL2.0 schema to describe the input-to-output mapping relationships. The service policy is then transformed into a policy binary tree so that the similarity between different Web services can be quantitatively evaluated. Furthermore, a new service redundancy detection approach is proposed based on this similarity. Finally, the case study and experimental analysis illustrate the applicability and capability of the proposed service redundancy detection approach.

Context-aware meta search engine for distributed web service

The ubiquity of the Internet and Web has led to the emergency of several Web search engines with varying capabilities. A weakness of existing search engines is the very extensive amount of hits that they can produce. Moreover, only a small number of web users actually know how to utilize the true power of Web search engines. Therefore, there is a need for searching infrastructure to help ease and guide the searching efforts of web users toward their desired objectives. In this paper, we propose a context-based meta-search engine and discuss its implementation on top of the actual Google.com search engine. The proposed meta-search engine benefits the user the most when the user does not know what exact document he or she is looking for. Comparison of the context-based meta-search engine with both Google and Guided Google shows that the results returned by context-based meta-search engine is much more intuitive and accurate than the results returned by both Google and Guided Google.

Web service to deliver filtered RSS items to a mobile application

In the past decade there has been massive growth of data on the internet. Many people rely on XML based RSS feeds to receive updates from websites. In this paper, we propose a method for managing the RSS feeds from various news websites. A web service is developed to deliver filtered news items from RSS feeds to a mobile client. Each news item is indexed, subsequently, the indexes are used for filtering news items. Indexing is done in two steps. First, classical text categorization algorithms are used to assign a category to each news item, second, geoparsing is used to assign geolocation data to each news item. An android application is developed to access filtered news items by consuming the proposed web service. A prototype is implemented using Rapid miner 5.0 as the data mining tool and SVM as the classification algorithm. Geoparsing and geocoding web services, and Android API are used to implement location-based access to news items. Experimental results prove that the proposed approach is effective and saves a significant amount of information overload processing time.

GRAPHICAL REPRESENTATIONS of MESSAGE EXCHANGES INTO WEB SERVICE-BASED APPLICATIONS

Web service-based application is an architectural style, where a collection of Web services communicate to each other to execute processes. With the popularity increase of Web service-based applications and since messages exchanged inside of this applications can be complex, we need tools to simplify the understanding of interrelationship among Web services. This work present a description of a graphical representation of Web service-based applications and the mechanisms inserted among Web service requesters and providers to catch information to represent an application. The major contribution of this paper is to discus and use HTTP and SOAP information to show a graphical representation similar to a UML sequence diagram of Web service-based applications.

A framework for monitoring and runtime recovery of web service-based applications

Service provisioning is a challenging research area for the design and implementation of autonomic service-oriented software systems. It includes automated QoS management for such systems and their applications. Monitoring, Diagnosis and Repair are three key features of QoS management. This work presents a self-healing Web service-based framework that manages QoS degradation at runtime. Our approach is based on proxies. Proxies act on meta-level communications and extend the HTTP envelope of the exchanged messages with QoS-related parameter values. QoS Data are filtered over time and analysed using statistical functions and the Hidden Markov Model. Detected QoS degradations are handled with proxies. We experienced our framework using an orchestrated electronic shop application (FoodShop).

A self-healing architecture for Web service-based applications

Web service-based application is an architectural style, where a collection of Web services communicates to each other to execute processes. With the popularity increase of developing Web service-based application and once Web services may change, in terms of functional and non-functional Quality of Service (QoS), we need mechanisms to monitor, diagnose, and repair Web services into a Web Application. This work presents a description of self-healing architecture that deals with these mechanisms. Other contributions of this paper are using the proxy server to measure Web service QoS values and to employ some strategies to recovery the effects from misbehaved Web services. © 2008 IEEE.

Web Service para geração de VRS no contexto de posicionamento GPS

Internet is fully inserted in contemporary society, specially in relation to entertainment services and trading. Its reach has transposed the traditional desktop computer models coming to mobile devices like cell phones and GPS receivers. Likewise, the scientific community takes its benefits, both for publication of studies and for communication between clusters processing information, such as at LHC, located in Switzerland. Concerning geodetic positioning, researches in the area present the concept of Virtual Reference Stations - VRS, in which is necessary a communication way between the real reference stations and a central system as well as between central system and a service requester. In this work, we analyze the current solutions for generation of VRS with regard to data delivery for the service requester and present a solution based on Web Services as an alternative to the model being developed by Spatial Geodesy Study Group – GEGE/FCT/UNESP. Comparing solutions, it was verified the potential of Web Services to aid in researches of geodetic positioning using VRS. Using such technology, it is obtained interoperability, providing greater flexibility to develop client applications, both development carried out by researchers of the university or by any person or enterprise wishing to use the service

A holistic approach to model-based testing of Web service compositions

The behavior of composed Web services depends on the results of the invoked services; unexpected behavior of one of the invoked services can threat the correct execution of an entire composition. This paper proposes an event-based approach to black-box testing of Web service compositions based on event sequence graphs, which are extended by facilities to deal not only with service behavior under regular circumstances (i.e., where cooperating services are working as expected) but also with their behavior in undesirable situations (i.e., where cooperating services are not working as expected). Furthermore, the approach can be used independently of artifacts (e.g., Business Process Execution Language) or type of composition (orchestration/choreography). A large case study, based on a commercial Web application, demonstrates the feasibility of the approach and analyzes its characteristics. Test generation and execution are supported by dedicated tools. Especially, the use of an enterprise service bus for test execution is noteworthy and differs from other approaches. The results of the case study encourage to suggest that the new approach has the power to detect faults systematically, performing properly even with complex and large compositions. Copyright © 2012 John Wiley & Sons, Ltd.