Semantic Web: An Integrated Approach for Web Service Discovery, Selection and Composition

Web services are remote methods can be invoked through open standards such as Simple Object Access Protocols. The increasing web services in the repositories makes the selection process very complex. The same can be extended in forming the composition of web services. This research focuses on the semantic web service selection and composition through design and implementation of a framework. The proposed framework is an ontology based service selection approach and the selected services are participating in the composition process. This approach deals with semantic search, which uses Quality of services for service selection and composition. The entire framework is implemented with semantic web technology and the performance of the system is observed with domain specific ontologies

Byzantine Fault Tolerant Coordination for Web Services Atomic Transactions

This thesis describes a Byzantine fault tolerant coordination framework for Web services atomic transactions. In the framework, all core services, including transaction activation, registration, completion, and distributed commit, are replicated and protected by Byzantine fault tolerance mechanisms. The traditional two-phase commit protocol is extended by a Byzantine fault tolerant version that can tolerate arbitrary faults on the coordinator and the initiator sides, and some types of malicious faults on the participant side. To achieve Byzantine fault tolerance in an efficient manner, and to limit the types of malicious behaviors of the coordinator, a novel decision certificate is introduced. The decision certificate includes a signed copy of the participants\u27 vote records, and it is piggybacked with all decision notifications to the participants for each participant to verify the legitimacy of the decision. The Byzantine fault tolerance mechanisms, together with the extended two-phase commit protocol, have been incorporated into an open-source framework supporting the standard Web services atomic transactions specification. Performance characterizations of the framework show that the implementation is fairly efficient. Such a Byzantine fault tolerant coordination framework can be useful for many transactional Web services that require a high degree of security and dependabilit

Byzantine Fault Tolerant Coordination for Web Services Atomic Transactions

This thesis describes a Byzantine fault tolerant coordination framework for Web services atomic transactions. In the framework, all core services, including transaction activation, registration, completion, and distributed commit, are replicated and protected by Byzantine fault tolerance mechanisms. The traditional two-phase commit protocol is extended by a Byzantine fault tolerant version that can tolerate arbitrary faults on the coordinator and the initiator sides, and some types of malicious faults on the participant side. To achieve Byzantine fault tolerance in an efficient manner, and to limit the types of malicious behaviors of the coordinator, a novel decision certificate is introduced. The decision certificate includes a signed copy of the participants\u27 vote records, and it is piggybacked with all decision notifications to the participants for each participant to verify the legitimacy of the decision. The Byzantine fault tolerance mechanisms, together with the extended two-phase commit protocol, have been incorporated into an open-source framework supporting the standard Web services atomic transactions specification. Performance characterizations of the framework show that the implementation is fairly efficient. Such a Byzantine fault tolerant coordination framework can be useful for many transactional Web services that require a high degree of security and dependabilit

Orchestrating Grid Services using BPEL and Globus Toolkit 4

Grid services exploit an emerging distributed computing technology that offers possibilities for distributed resource sharing and collaboration. The standards for WSRF (Web Service Resource Framework) have allowed grid services to converge more closely on web services. Composing web services has attracted significant effort and commercial interest. This has resulted in BPEL (Business Process Execution Logic) as a standard way of orchestrating web services. Because of the similarities with web services, there is a natural question of whether grid services can be orchestrated in like manner. It is explained how CRESS (Chisel Representation Employing Systematic Specification) has been extended to describe grid service composition. It will be seen how BPEL has been adapted for this purpose, using ActiveBPEL as the orchestration engine and Globus Toolkit 4 as the grid service container. The problems arising with orchestrating grid services are discussed, along with possible workarounds

An intelligent framework for dynamic web services composition in the semantic web

As Web services are being increasingly adopted as the distributed computing technology of choice to securely publish application services beyond the firewall, the importance of composing them to create new, value-added service, is increasing. Thus far, the most successful practical approach to Web services composition, largely endorsed by the industry falls under the static composition category where the service selection and flow management are done a priori and manually. The second approach to web-services composition aspires to achieve more dynamic composition by semantically describing the process model of Web services and thus making it comprehensible to reasoning engines or software agents. The practical implementation of the dynamic composition approach is still in its infancy and many complex problems need to be resolved before it can be adopted outside the research communities. The investigation of automatic discovery and composition of Web services in this thesis resulted in the development of the eXtended Semantic Case Based Reasoner (XSCBR), which utilizes semantic web and AI methodology of Case Based Reasoning (CBR). Our framework uses OWL semantic descriptions extensively for implementing both the matchmaking profiles of the Web services and the components of the CBR engine. In this research, we have introduced the concept of runtime behaviour of services and consideration of that in Web services selection. The runtime behaviour of a service is a result of service execution and how the service will behave under different circumstances, which is difficult to presume prior to service execution. Moreover, we demonstrate that the accuracy of automatic matchmaking of Web services can be further improved by taking into account the adequacy of past matchmaking experiences for the requested task. Our XSCBR framework allows annotating such runtime experiences in terms of storing execution values of non-functional Web services parameters such as availability and response time into a case library. The XSCBR algorithm for matchmaking and discovery considers such stored Web services execution experiences to determine the adequacy of services for a particular task. We further extended our fundamental discovery and matchmaking algorithm to cater for web services composition. An intensive knowledge-based substitution approach was proposed to adapt the candidate service experiences to the requested solution before suggesting more complex and computationally taxing AI-based planning-based transformations. The inconsistency problem that occurs while adapting existing service composition solutions is addressed with a novel methodology based on Constraint Satisfaction Problem (CSP). From the outset, we adopted a pragmatic approach that focused on delivering an automated Web services discovery and composition solution with the minimum possible involvement of all composition participants: the service provider, the requestor and the service composer. The qualitative evaluation of the framework and the composition tools, together with the performance study of the XSCBR framework has verified that we were successful in achieving our goal

Cyberaide JavaScript: A Web Application Development Framework for Cyberinfrastructure

This thesis work introduces a service oriented architecture based Grid abstraction framework that allows users to access Grid infrastructure through JavaScript. Such a framework integrates well with other Web 2.0 technologies since it provides JavaScript toolkit to build web applications. The framework consists of two essential parts. A client Application Programming lnterface (API) to access the Grid via JavaScript and a full service stack in server side through which the Grid access is channeled. The framework uses commodity Web service standards and provides extended functionality such as asynchronous task management, file transfer, etc. The availability of this framework simplifies not only the development of new services, but also the development of advanced client side Grid applications that can be accessed through Web browsers. The effectiveness of the framework is demonstrated by providing an Grid portal example that integrates a variety of useful services to be accessed through a JavaScript enabled client desktop via a Web browser, as well as the opensocial gadgets for Grid task management and file transfer. Overall, Grid developers will have another tool at their disposal that projects a simpler way to distribute and maintain cyberinfrastructure related software, while simultaneously delivering advanced interfaces and integrating social services for the scientific community

Competence Checking for the Global E-Service Society Using Games

We study the problem of checking the competence of communicative agents operating in a global society in order to receive and offer electronic services. Such a society will be composed of local sub-societies that will often be semi-open, viz., entrance of agents in a semi-open society is conditional to specific admission criteria. Assuming that a candidate agent provides an abstract description of their communicative skills, we present a test that a controller agent could perform in order to decide if a candidate agent should be admitted. We formulate this test by revisiting an existing knowledge representation framework based on games specified as extended logic programs. The resulting framework finds useful application in complex and inter-operable web-services construed as semi-open societies in support of the global vision known as the Semantic Web