Dynamic Web Service Selection Research Articles

Dynamic Transaction Aware Web Service Selection

Web service composition, that recursively constructs a composite web service out of the existing services based on a business workflow has been acknowledged as a promising approach to meet the user demands, whenever a single service alone cannot fulfil the needs. In view of frequent failures in the internet environment where the composed service is executed, reliability of the composed service must be ensured. The reliability is determined by the behavioral or transactional properties of component services. The component services for each activity of the workflow must be selected based on their behavior so that their execution results in a consistent termination. Service selection must happen at run-time in order to consider the services available in a service registry at the time of execution. Towards this need, a dynamic transaction aware web service selection approach is proposed in this paper. Further, whenever user requirements change, a long running transaction must be interrupted and cancelled which is not addressed by any of the existing works. Hence, service cancellability property is proposed in this paper and incorporated in the dynamic selection approach. The overhead of the proposed run-time selection approach is assessed and the impact of increased services on its performance is also measured.

A Web Service Selection Model using Cognitive Parameters

Semantic Web Service is considered to be the crux of Dynamic Web Service Selection. It looks forward to automate the different aspects of Service Selection which includes Web Service Discovery, Service Selection, Service Composition and Service Invocation. This paper aims at better understanding the Service Selection aspect of Semantic Web Service giving cognitive parameters the center stage. It looks at the psychological and basic behavioral aspect of consumer behavior. A model for Service Selection is proposed wherein an attempt has been made to measure the consumer behavior using cognitive parameters. A detailed study of these cognitive parameters has been made from both the service provider’s context and the service consumer’s context. These parameters are then used to perform the service selection effectively and efficiently. The cognitive parameters help in efficient modeling of user’s requirements and thus leading to better service selection.

Dynamic web service selection group decision-making method based on hybrid QoS

Open and dynamic internet environment, multi-period QoS and multiple QoS registry centres increased the difficulty of service selection. To solve difficulties above, a hybrid QoS model is introduced supporting real numbers, interval numbers, triangular fuzzy numbers and intuitionistic fuzzy numbers and multi-period hybrid QoS aggregating operator firstly. Furthermore, dynamic web service selection group decision-making method based on hybrid QoS DWSSGDM_HQ is presented to support proposed models of QoS, multiple QoS registry centres. DWSSGDM_HQ includes four main steps: converting hybrid QoS into intervals, calculating weighted normalised decision-matrix, determining the group positive-ideal and group negative-ideal solution, and calculating the close-degrees of candidates. Finally, some experiments are given using actual QoS data to demonstrate the benefits and effectiveness of our approach.

A QoS towards Dynamic Web services Recapitulation and Selection

Web services are the components, communicates via Internet or Web. Fundamental vision of the Web service is a brokerage system. The Recapitulation of Web service is an approach for the effective integration of distributed, heterogeneous and autonomous applications to build more Structured and value added services. Web services selection algorithms are required to find and select the best services. A QoS is a benchmark to select the best service for the task of composition. The QoS broker based web service selection plays an important role in service-oriented computing, where most of the applications are user specific QoS services. Here we propose a Broker based architecture for selection of web services. The importance of the web services selection algorithm is to maximize the QoS of the web services recapitulation using complex service provider's (CSP) QoS requirement parameters. This paper have discussed about different Web service Service-offers. We have classified the CSP’s requirements defined on the QoS and Service-offers based on its structure. This paper presents an efficient method to finding the suitable web service based on the consumer’s requirements along with QoS.

Dynamic Web service selection group decision-making based on heterogeneous QoS models

In open and dynamic Internet environment, multi-periods quality of service (QoS), multiple decision-makers based on heterogeneous QoS models and uncertainty weights make optimal Web service selection hard. To solve the difficulties above, dynamic Web service selection group decision-making based on heterogeneous QoS models (DWSSGD_HQM) is proposed. Drawing on and extending technique for order preference by similarity to ideal solution (TOPSIS), DWSSGD_HQM supports multiple decision-makers based on heterogeneous QoS models expressed in real numbers, interval numbers, triangular fuzzy numbers and intuitionistic fuzzy numbers respectively, and takes multi-periods QoS and weights of user and group into account. Six steps are detailed. They are converting heterogeneous QoS models into ones expressed in interval numbers, calculating weighted normalized decision-matrix, determining the group positive-ideal and negative-ideal solutions, calculating the close-degrees of candidates, aggregating close-degrees of multi-periods for each decision-maker, and ranking the alternatives. Finally, experiments are conducted by using actual QoS data to evaluate the effectiveness of the proposed approach.

A hybrid approach for efficient Web service composition with end-to-end QoS constraints

Dynamic selection of Web services at runtime is important for building flexible and loosely-coupled service-oriented applications. An abstract description of the required services is provided at design-time, and matching service offers are located at runtime. With the growing number of Web services that provide the same functionality but differ in quality parameters (e.g., availability, response time), a decision needs to be made on which services should be selected such that the user's end-to-end QoS requirements are satisfied. Although very efficient, local selection strategy fails short in handling global QoS requirements. Solutions based on global optimization, on the other hand, can handle global constraints, but their poor performance renders them inappropriate for applications with dynamic and realtime requirements. In this article we address this problem and propose a hybrid solution that combines global optimization with local selection techniques to benefit from the advantages of both worlds. The proposed solution consists of two steps: first, we use mixed integer programming (MIP) to find the optimal decomposition of global QoS constraints into local constraints. Second, we use distributed local selection to find the best Web services that satisfy these local constraints. The results of experimental evaluation indicate that our approach significantly outperforms existing solutions in terms of computation time while achieving close-to-optimal results.

Dynamic Selection of Web Services based on Collaborative Filtering

Dynamic Selection of Web Services based on Collaborative Filtering

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

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.

A new QoS ontology and its QoS-based ranking algorithm for Web services

Web service composition is a promising solution for building distributed applications on the Internet in which Web service discovery is a key step. With a number of Web services having similar functionality, it is necessary to rank those services to select the best Web services for a request. QoS information which can reflect user’s expectation and experience of using a service is often used as a distinguish factor in a service ranking algorithm. Different service providers and participants may use different QoS concepts for describing service quality information. Therefore, it leads to the issue of semantic interoperability of QoS. In this paper, we propose a novel approach for designing and developing a QoS ontology and its QoS-based ranking algorithm for evaluating Web services. The QoS ontology can support not only describing QoS information in great detail but also facilitating various service participants expressing their QoS offers and demands at different levels of expectation. The QoS-based ranking algorithm adopted Analytic Hierarchy Process (AHP), a multiple criteria decision making technique, as an underlying mechanism for developing a flexible and dynamic ranking algorithm. The proposed QoS ontology and ranking algorithm can be used in various applications in order to facilitate automatic and dynamic discovery and selection of Web services.

Dynamic services selection algorithm in Web services composition supporting cross-enterprises collaboration

Based on the deficiency of time convergence and variability of Web services selection for services composition supporting cross-enterprises collaboration, an algorithm QCDSS (QoS constraints of dynamic Web services selection) to resolve dynamic Web services selection with QoS global optimal path, was proposed. The essence of the algorithm was that the problem of dynamic Web services selection with QoS global optimal path was transformed into a multi-objective services composition optimization problem with QoS constraints. The operations of the cross and mutation in genetic algorithm were brought into PSOA (particle swarm optimization algorithm), forming an improved algorithm (IPSOA) to solve the QoS global optimal problem. Theoretical analysis and experimental results indicate that the algorithm can better satisfy the time convergence requirement for Web services composition supporting cross-enterprises collaboration than the traditional algorithms.

Dynamic Web Service Selection for Reliable Web Service Composition

This paper studies the dynamic web service selection problem in a failure-prone environment, which aims to determine a subset of Web services to be invoked at run-time so as to successfully orchestrate a composite web service. We observe that both the composite and constituent web services often constrain the sequences of invoking their operations and therefore propose to use finite state machine to model the permitted invocation sequences of Web service operations. We assign each state of execution an aggregated reliability to measure the probability that the given state will lead to successful execution in the context where each web service may fail with some probability. We show that the computation of aggregated reliabilities is equivalent to eigenvector computation and adopt the power method to efficiently derive aggregated reliabilities. In orchestrating a composite Web service, we propose two strategies to select Web services that are likely to successfully complete the execution of a given sequence of operations. A prototype that implements the proposed approach using BPEL for specifying the invocation order of a web service is developed and served as a testbed for comparing our proposed strategies and other baseline Web service selection strategies.

A workflow portal supporting multi‐language interoperation and optimization

AbstractIn this paper we present a workflow portal for Grid applications, which supports different workflow languages and workflow optimization. We present an XSLT converter that converts from one workflow language to another and enables the interoperation between different workflow languages. We discuss strategies for choosing the optimal service from several semantically equivalent Web services in a Grid application. The dynamic selection of Web services involves discovering a set of semantically equivalent services by filtering the available services based on metadata, and selecting an optimal service based on real‐time data and/or historical data recorded during prior executions. Finally, we describe the framework and implementation of the workflow portal which aggregates different components of the project using Java portlets. Copyright © 2007 John Wiley & Sons, Ltd.

Aspect-oriented Programming for Dynamic Web Service Selection, Integration and Management

In service-oriented computing, applications are often created by integrating third-party Web Services. Current integration approaches, however, require client applications to hardcode references to specific Web Services, thereby affecting adaptability and robustness. Moreover, support for client-side management is rarely provided. To enable the development of more flexible and robust applications, we propose to insert a new layer between the client applications and the Web Services: the Web Services Management Layer (WSML). This layer decouples Web Services from client applications and enables hot-swapping between semantically equivalent Web Services based on availability. This mechanism allows for dynamic switching between Web Services based on selection policies that encapsulate changing business requirements. In addition, with WSML, client-side management concerns (e.g., caching, billing and logging) can be decoupled from the applications. In this paper, we identify a list of requirements for WSML to realize dynamic integration and client-side service management, and provide support for service criteria to govern the selection, integration and composition of Web Services. We also show that dynamic Aspect-Oriented Programming (AOP) is well suited to implement the core functionality of WSML.

A Dynamic Web Services Selection Algorithm with QoS Global Optimal in Web Services Composition

As a new Web pattern, Web service has been rapidly developed in recent years. How to dynamically integrate the existent Web services to form a newly value-added and complex service to meet the requirement of different users is a popular research area. This paper presents an algorithm GODSS (global optimal of dynamic Web services selection) to resolve dynamic Web services selection with QoS global optimal in Web services composition. The essence of the algorithm is that the problem of dynamic Web Service selection with QoS global optimal is transformed into a multi-objective services composition optimization with QoS constraints. The theory of intelligent optimization of multi-objective genetic algorithm is utilized to produce a set of optimal Pareto services composition process with constraint principle by means of optimizing various objective functions simultaneously. Theoretical analysis and experimental results indicate the feasibility and efficiency of this algorithm.

Network mapping services for dynamic selection of web services: promises and challenges

Web services provide the possibility of dynamically integrating distributed service components scattered over the Internet to fulfill sophisticated business demands. The effectiveness of service integration depends critically on the selection of best-fit service components. In this paper, we first review several research streams related to server selection. We then propose a framework of dynamic service discovery, termed Network Mapping Services (NMS), which combines prior efforts on network-aware applications and server selection into a coherent structure. As successful implementation of NMS requires the collaboration among all participating service providers, we also discuss several incentive schemes and compare their effectiveness in supporting collaboration.

A framework and ontology for dynamic Web services selection

Current Web services standards lack the means for expressing a service's nonfunctional attributes - namely, its quality of service. QoS can be objective (encompassing reliability, availability, and request-to-response time) or subjective (focusing on user experience). QoS attributes are key to dynamically selecting the services that best meet user needs. This article addresses dynamic service selection via an agent framework coupled with a QoS ontology. With this approach, participants can collaborate to determine each other's service quality and trustworthiness.