scholarly journals Towards Dynamic Reconfiguration of a Composite Web Service: An Approach Based on QoS Prediction

Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1597
Author(s):  
Abdessalam Messiaid ◽  
Farid Mokhati ◽  
Rohallah Benaboud ◽  
Hajer Salem

Service-oriented architecture provides the ability to combine several web services in order to fulfil a user-specific requirement. In dynamic environments, the appearance of several unforeseen events can destabilize the composite web service (CWS) and affect its quality. To deal with these issues, the composite web service must be dynamically reconfigured. Dynamic reconfiguration may be enhanced by avoiding the invocation of degraded web services by predicting QoS for the candidate web service. In this paper, we propose a dynamic reconfiguration method based on HMM (Hidden Markov Model) states to predict the imminent degradation in QoS and prevent the invocation of partner web services with degraded QoS values. PSO (Particle Swarm Optimization) and SFLA (Shuffled Frog Leaping Algorithm) are used to improve the prediction efficiency of HMM. Through extensive experiments on a real-world dataset, WS-Dream, the results demonstrate that the proposed approach can achieve better prediction accuracy. Moreover, we carried out a case study where we revealed that the proposed approach outperforms several state-of-the-art methods in terms of execution time.

2011 ◽  
Vol 20 (04) ◽  
pp. 357-370 ◽  
Author(s):  
D. PAULRAJ ◽  
S. SWAMYNATHAN ◽  
M. MADHAIYAN

One of the key challenges of the Service Oriented Architecture is the discovery of relevant services for a given task. In Semantic Web Services, service discovery is generally achieved by using the service profile ontology of OWL-S. Profile of a service is a derived, concise description and not a functional part of the semantic web service. There is no schema present in the service profile to describe the input, output (IO), and the IOs in the service profile are not always annotated with ontology concepts, whereas the process model has such a schema to describe the IOs which are always annotated with ontology concepts. In this paper, we propose a complementary sophisticated matchmaking approach which uses the concrete process model ontology of OWL-S instead of the concise service profile ontology. Empirical analysis shows that high precision and recall can be achieved by using the process model-based service discovery.


Author(s):  
Tony Clark ◽  
Balbir S. Barn ◽  
Vinay Kulkarni

Component-based approaches generalize basic object-oriented implementations by allowing large collections of objects to be grouped together and externalized in terms of public interfaces. A typical component-based system will include a large number of interacting components. Service-Oriented Architecture (SOA) organizes a system in terms of components that communicate via services. Components publish services that they implement as business processes. Consequently, a change to a single component can have a ripple effect on the service-driven system. Component reconfiguration is motivated by the need to evolve the component architecture and can take a number of forms. The authors define a dynamic architecture as one that supports changing the behavior and topology of existing components without stopping, updating, and redeploying the system. This chapter addresses the problem of dynamic reconfiguration of component-based architectures. It proposes a reification approach that represents key features of a language in data, so that a system can reason and dynamically modify aspects of it. The approach is described in terms of a new language called µLEAP and validated by implementing a simple case study.


2014 ◽  
Vol 11 (2) ◽  
pp. 67-84 ◽  
Author(s):  
Tanveer Ahmed ◽  
Abhishek Srivastava

Service oriented architecture has revolutionized the way a traditional business process is executed. The success of this architecture is Indue to the composition of multiple heterogeneous services at runtime. Web service composition is a mechanism where several web services are combined at runtime to build a complex application for a user. It is one of the most sought after processes in the context of semantic web. But, composition of web services at runtime is a difficult task owing to the availability of multiple service providers offering the same functionality. The process if exasperated by due conflicting preferences of a service consumer. In this paper, the authors address the issue of selecting a service based on Quality of Service (QoS) attributes. They utilize concepts customized from physics to create an environment that facilitates the selection of a best service from the set of similar services. The technique not only facilitates the selection of the service with the best QoS attributes, but distributes the load among expeditiously. Here in this paper, the authors concentrate on minimizing and equitably balancing the waiting time for a user. They conduct in silico experiments on multiple workflows to demonstrate the efficacy of the proposed technique to balance load efficiently among similar service offerings.


Author(s):  
Peishing Zhao ◽  
Genong Yu ◽  
Liping Di

As Web service technologies mature in recent years, a growing number of geospatial Web services designed to interoperate spatial information over the network have emerged. Geospatial Web services are changing the way in which spatial information systems and applications are designed, developed and deployed. This chapter introduces all aspects of geospatial Web services from service-oriented architecture to service implementation. It covers the life cycle of geospatial Web services in terms of geospatial interoperable standards, including publish, discovery, invocation and orchestration. To make geospatial Web services more intelligent, semantic issues about geospatial data and services are discussed here. Furthermore, the applications of standard-compliant geospatial Web service are also reviewed.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Ying Jin ◽  
Guangming Cui ◽  
Yiwen Zhang

Service-oriented architecture (SOA) is widely used, which has fueled the rapid growth of Web services and the deployment of tremendous Web services over the last decades. It becomes challenging but crucial to find the proper Web services because of the increasing amount of Web services. However, it proves unfeasible to inspect all the Web services to check their quality values since it will consume a lot of resources. Thus, developing effective and efficient approaches for predicting the quality values of Web services has become an important research issue. In this paper, we propose UIQPCA, a novel approach for hybrid User and Item-based Quality Prediction with Covering Algorithm. UIQPCA integrates information of both users and Web services on the basis of users’ ideas on the quality of coinvoked Web services. After the integration, users and Web services which are similar to the target user and the target Web service are selected. Then, considering the result of integration, UIQPCA makes predictions on how a target user will appraise a target Web service. Broad experiments on WS-Dream, a web service dataset which is widely used in real world, are conducted to evaluate the reliability of UIQPCA. According to the results of experiment, UIQPCA is far better than former approaches, including item-based, user-based, hybrid, and cluster-based approaches.


2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Hossein Nematzadeh ◽  
Homayun Motameni ◽  
Radziah Mohamad ◽  
Zahra Nematzadeh

Workflow-based web service compositions (WB-WSCs) is one of the main composition categories in service oriented architecture (SOA). Eflow, polymorphic process model (PPM), and business process execution language (BPEL) are the main techniques of the category of WB-WSCs. Due to maturity of web services, measuring the quality of composite web services being developed by different techniques becomes one of the most important challenges in today’s web environments. Business should try to provide good quality regarding the customers’ requirements to a composed web service. Thus, quality of service (QoS) which refers to nonfunctional parameters is important to be measured since the quality degree of a certain web service composition could be achieved. This paper tried to find a deterministic analytical method for dependability and performance measurement using Colored Petri net (CPN) with explicit routing constructs and application of theory of probability. A computer tool called WSET was also developed for modeling and supporting QoS measurement through simulation.


Kybernetes ◽  
2017 ◽  
Vol 46 (3) ◽  
pp. 479-500 ◽  
Author(s):  
Kushal Anjaria ◽  
Arun Mishra

Purpose Any computing architecture cannot be designed with complete confidentiality. As a result, at any point, it may leak the information. So, it is important to decide leakage threshold in any computing architecture. To prevent leakage more than the predefined threshold, quantitative analysis is helpful. This paper aims to provide a method to quantify information leakage in service-oriented architecture (SOA)-based Web services. Design/methodology/approach To visualize the dynamic binding of SOA components, first, the orchestration of components is modeled. The modeling helps to information-theoretically quantify information leakage in SOA-based Web services. Then, the paper considers the non-interference policy in a global way to quantify information leakage. It considers not only variables which interfere with security sensitive content but also other architectural parameters to quantify leakage in Web services. To illustrate the attacker’s ability, a strong threat model has been proposed in the paper. Findings The paper finds that information leakage can be quantified in SOA-based Web services by considering parameters that interfere with security sensitive content and information theory. A hypothetical case study scenario of flight ticket booking Web services has been considered in the present paper in which leakage of 18.89 per cent information is calculated. Originality/value The paper shows that it is practically possible to quantify information leakage in SOA-based Web services. While modeling the SOA-based Web services, it will be of help to architects to identify parameters which may cause the leakage of secret contents.


Author(s):  
L S RajivKrishna ◽  
Y Prasanth

<p>Web services provides a distributed computing architecture, with an emerging way of service oriented architecture (SQA). Here service oriented architecture is an interface to both computer systems and web services. Which implements an interaction with each other in new and different ways. According to service oriented architecture it virtually provides a platform for web services to communicate with each other. As it was an easy way for communicating with both clients and services. Many organizations and companies are either evaluating themselves into an enterprise information architectures, or they are in the process of getting adopt to the web services technology. As web services are platform independent it is playing a major role in the enterprise environment, and currently web services are widely accepted by many companies and organizations. So commonly web services possess some challenges to the enterprise environment. As a part of it web service must be tested before publish into a service oriented architecture. It involves large number of test cases, test scenarios that takes more time and effort. Testing management is needed so that it should control the time effort and should reduce the complexity of web service in a large software system, also in a real time world. Automation testing faces these challenges and fixes these issues. Automation testing has an ability to handle the complexities which are experiencing by the web services in a current environment. This paper presents the automatic testing strategies of a web service and detect the problems between both manual and automation testing. Finally results shows the proper effective report on improving the visibility of testing process based on the web approach to enhance the critical communication among multiple testing groups.</p>


2017 ◽  
Vol 1 (2) ◽  
pp. 36
Author(s):  
Alfian Ardiyanta R ◽  
Imam Fahrur R ◽  
Rudy Ariyanto

Layanan e-Commerce merupakan suatu aplikasi yang dapat membantu merchant dalam pembuatan online shop. Dalam pembangunan Layanan e-Commerce metode untuk arsitektur aplikasi yang dapat digunakan adalah Service Oriented Architecture (SOA). SOA adalah suatu teknologi arsitektur pengembangan perangkat lunak dengan pendekatan Service, memungkinkan hubungan dan pertukaran data atau informasi antar bagian menjadi mudah dan merupakan solusi dalam menghadapi permasalahan dalam bidang pengolahan data atau informasi suatu organisasi yang terus berkembang. Berdasarkan analisis SOA pada layanan e-Commerce dihasilkan 10 service utama yaitu merchant service, login service, kategori service, produk service, order service, confirmation payment service, customer service, setting service, akun bank service, dan blog service. Dalam penelitian ini service utama dirancang dan implementasikan pada aplikasi Layanan e-Commerce menggunakan web services. Simpulan dari penelitian ini, perancangan dan penerapan suatu e-Commerce bagi organisasi yang bisnis prosesnya terus berubah dan berkembang mengikuti kebutuhan sangat tepat menggunakan analisa dan perancangan berbasis Service Oriented Architecture dengan menggunakan Web Service.


Author(s):  
Faîçal Felhi ◽  
Jalel Akaichi

Real time impact in many applications is the subject of a recent field of studies in information systems. Web services are a solution for the integration of distributed information systems that are autonomous, heterogeneous and auto adaptable to the context. This impact can resolve many problems in different systems based on Service Oriented Architecture (SOA) and web services. In this paper, the authors are interested in defining an approach to provide the different needs of self-adaptability of SOA to the context based on workflow, define the real time goal in their approach and show the feasibility and performance evaluation of their approach in an ambulance trajectory case study.


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