Web Service selection is a key component in service-oriented computing. Service-oriented Architectures follow the find-bindexecute paradigm in which service providers register their services in public or private registries, which clients use to locate web services. The QoS based web service selection mechanisms plays an essential role in service-oriented architectures, because most of the applications want to use services that accurately meet their requirements. Currently, the UDDI catalogue supports only primitive matching mechanisms and provides no control over the quality of registered services. We propose a QoS broker based architecture for dynamic web service selection which facilitates the clients to specify the non-functional requirements like QoS along with functional requirements. The paper presents an efficient mechanism for finding the most suitable web service according to the consumer’s requirements.

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An Efficient WS-QoS Broker Based Architecture for Web Services Selection

Web service is a new paradigm of using the Web. One of the fundamental supports of the web service vision is a brokerage system that enables services to be published to a searchable repository and later retrieved by potential users. Automated Web service discovery is a key challenge in Service Oriented Architecture (SOA) research. There exist many web services which exhibit similar functional characteristics. It is imperative to provide service consumers with facilities for discovering required web services according to their nonfunctional aspects like QoS. An important issue arising from Web Service applications is how to conveniently, accurately and efficiently retrieve services from large-scale and expanding service repositories. The QoS based web service discovery play an essential role in SOA because most of the applications want to use services that accurately meet their requirements. We propose the agent-based architecture for dynamic Web service discovery which facilitates the requester to specify his/her QoS requirements along with functional requirements. In this paper, we propose a novel approach for designing and developing an agent-based architecture and its QoS-based matching, ranking and selection algorithm for evaluating web services. The paper presents an optimal approach for finding the most suitable web service according to the consumer's requirements.

An optimal agent-based architecture for dynamic Web service discovery with QoS

The cloud is an outstanding platform to deal with functionally equivalent services which are exponentially increasing day-by-day. The selection of services to meet the client requirements is a subtle task. The services can be selected by ranking all the candidate services using their network and non-network Quality-of-Service (QoS) parameters, which is formulated as a NP hard optimization problem. In this paper, we proposed a linear discriminant analysis (LDA) based a four level matching model for service selection based on QoS parameters, which includes description matching of a service, matchmaking phase, LDA-based QoS matching and ranking. The LDA-service selection agent is deployed on each cloud to classify services into classes and rank the services based on the aggregate QoS value of each service. Finally, the test results show the efficiency in service selection with minimal discovery overhead, significant reduction in the computation time and the number of candidate services to be considered.

A Four-level Linear Discriminant Analysis Based Service Selection in the Cloud Environment

The SOA enables the development of flexible large scale-applications in open environments by dynamically combining the web services. There exist many web services which exhibit similar functional characteristics. It is imperative to provide service consumers with facilities for selecting required web services according to their non-functional characteristics or QoS. An important issue arising from Web Service applications is how to conveniently, accurately and efficiently retrieve services from large-scale and expanding service repositories. The QoS based web service discovery play an essential role in SOA because most of the applications want to use services that accurately meet their requirements. This work proposes a web service discovery mechanism in which the functional and non-functional requirements are taken into account during service discovery. In this paper, we propose a novel approach for designing and developing a agent-based architecture and its QoS-based matching, ranking and selection algorithm for evaluating web services. The paper presents an optimal approach for discovering the most suitable web service according to the consumer’s functional and quality requirements.

http://www.jatit.org/volumes/research-papers/Vol15No2/2Vol15No2.pdf

An efficient architecture for agent-based dynamic web service discovery with qos

As a service-based language, WS-BPEL (the Web service Business Process Execution Language) is widely adopted into enterprise solutions. However, because of the intrinsic flexibility and dynamism of the Web services it used, its behavior couldn't be foreseen until it is running, runtime monitoring is needed. The paper proposed a novel solution to the problem of monitoring Web services instances implemented in BPEL. The solution introduces Monitor Broker into traditional Web services architecture to access Web service runtime state information and calculate the QoS(Quality of service)property values, Monitor Broker architecture is devised with the support of Aspect Oriented Programming(AOP) that clearly separates the business logic of a Web service from its monitoring functionality. The initial implementation and experiment with a travel reservation service example shows that this approach is feasible and the monitoring cost is affordable.

Runtime monitoring Web services implemented in BPEL

Web service technology is playing a major role in today's distributed system computing. The wide adoption of web services raises the challenging problem of service discovery. With an increasing number of Web services providing similar functionalities, Quality of Service (QoS) is becoming an important criterion for selecting of the best available service. We aim to refine the discovery process through designing a new framework that enhances retrieval algorithms by combining syntactic and semantic matching of services. We propose a model of QoS-based Web services discovery that combines an augmented UDDI registry to publish the QoS information.

P. Balasubramanie

Papers

An efficient framework for agent-based quality driven Web Services discovery