scholarly journals Qos Correlation with Constraint Based Optimal Service Selection in Composition

2021 ◽  
Vol 23 (06) ◽  
pp. 857-867
Author(s):  
Yashwant Dongre ◽  
◽  
Rajesh Ingle ◽  

In a service-oriented architecture, service composition plays an important role as a key technology for integrating complex web applications. The service selection as part of the service composition process attracted towards Quality of Service as mandatory criteria for optimal selection of services for the composition process. While fulfilling the non-functional requirements from the user among a functionally similar list of services is a very challenging task. Web services are treating Software as a Service for building web applications. The Quality of Service correlation of services with constraints for selection of service is proposed in this paper. Experimental results of correlation without constraint method and proposed method show that our method outperforms over existing approach.

Author(s):  
Hanane Becha ◽  
Gunter Mussbacher ◽  
Daniel Amyot

Non-functional properties (NFPs) represent an important facet of service descriptions, especially in a Service Oriented Architecture. Yet, they are seldom explicitly described, and their use in service selection and composition is still limited. This chapter presents the User Requirements Notation (URN) as a means to model and analyze functional and non-functional service requirements. Aspect-oriented extensions to URN (AoURN) enable the modeling and modularization of different concerns, including non-functional requirements, which can crosscut services or service components. The chapter also proposes a taxonomy of NFPs used to annotate services and service compositions modeled with AoURN. These annotations enable the specification of quantitative non-functional values for services, guide service selection, and support the computation of the NFP (e.g., the quality of service) of their composition. This approach is illustrated with a simple yet realistic composite service (BookItWell), with an emphasis on four types of NFPs, namely service cost, response time, reliability, and availability.


Author(s):  
Yusuf Lateef Oladimejia

The realisation of Service-Oriented Architecture (SOA) to communicate data between systems running on different platforms lack an organised framework to capture the essential elements required for successful interoperability between web applications and their services. In this work, a SOA for Data Interoperability in Web Applications (SOADIWA) was designed. The architecture of SOADIWA was based on five layers, namely Web Application Layer (WAL), Quality of Service Assurance Certifier Layer (QoSACL), Web Service Layer (WSL), Visualization Input Layer (VIL) and Visualization Output Layer (VOL). In WAL, the Service Requester (SR) initiates a request for data from the Service Provider (SP) through the QoSACL to provide appropriate website via WSL for rendering of services which must be accepted, processed and returned for a particular need in VIL. The requested data is filtered in VIL for data exploration and analysis in VOL using context-sensitive visualization techniques. The purpose of QoSACL is to check and verify the claims made by the SP about its quality of service. This enabled the SR to choose the service that satisfied its needs. The implementation comprised of Java Script, Microsoft Visual Studio 2017 and NuGet packages; while the experiment was simulated on LoadUI pro application. Standard metrics such as Optimal Performance (OP) and Phased Effort Distribution (PED) were developed to test SOADIWA. These results conformed to basic web service interoperability. The work led to the integration of a host of techniques towards the creation of a novel tool that is useful in web domain using SOA approach.


Author(s):  
Aimrudee Jongtaveesataporn ◽  
Shingo Takada

The selection of services is a key part of Service Oriented Architecture (SOA). Services are primarily selected based on function, but Quality of Service (QoS) is an important factor when choosing among several services with the same function. But current service selection approaches often takes time to unnecessarily recompute requests. Furthermore, if the same service is chosen as having the "best" QoS for multiple selections, this may result in that service having too much load. We thus propose the FASICA (FAst service selection for SImilar constraints with CAche) Framework which chooses a service with satisfactory QoS as quickly as possible. The key points are (1) to use a cache which stores previous search results, (2) to use K-Nearest Neighbor (K-NN) algorithm with K-d tree when a satisfactory service does not exist in the cache, and (3) to distribute the service request according to a distribution policy. Results of simulations show that our framework can rapidly select a service compared to a conventional approach.


Author(s):  
Bassam Al Shargabi ◽  
Osama Al-haj Hassan ◽  
Alia Sabri ◽  
Asim El Sheikh

Software is gradually becoming more built by composing web services to support enterprise applications integration; thus, making the process of composing web services a significant topic. The Quality of Service (QoS) in web service composition plays a crucial role. As such, it is important to guarantee, monitor, and enforce QoS and ability to handle failures during execution. Therefore, an urgent need exists for a dynamic Web Service Composition and Execution (WSCE) framework based on QoS constraints. A WSCE broker is designed to maintain the following function: intelligent web service selection decisions based on local QoS for individual web service or global QoS based selection for composed web services, execution tracking, and adaptation. A QoS certifier controlled by the UDDI registry is proposed to verify the claimed QoS attributes. The authors evaluate the composition plan along with performance time analysis.


Author(s):  
Bassam Al Shargabi ◽  
Osama Al-haj Hassan ◽  
Alia Sabri ◽  
Asim El Sheikh

Software is gradually becoming more built by composing web services to support enterprise applications integration; thus, making the process of composing web services a significant topic. The Quality of Service (QoS) in web service composition plays a crucial role. As such, it is important to guarantee, monitor, and enforce QoS and ability to handle failures during execution. Therefore, an urgent need exists for a dynamic Web Service Composition and Execution (WSCE) framework based on QoS constraints. A WSCE broker is designed to maintain the following function: intelligent web service selection decisions based on local QoS for individual web service or global QoS based selection for composed web services, execution tracking, and adaptation. A QoS certifier controlled by the UDDI registry is proposed to verify the claimed QoS attributes. The authors evaluate the composition plan along with performance time analysis.


Author(s):  
Christoph Rathfelder ◽  
Benjamin Klatt ◽  
Franz Brosch ◽  
Samuel Kounev

With the introduction of services, systems become more flexible as new services can easily be composed out of existing services. Services are increasingly used in mission-critical systems and applications, and therefore, considering Quality of Service (QoS) properties is an essential part of the service selection. Quality prediction techniques support the service provider in determining possible QoS levels that can be guaranteed to a customer or in deriving the operation costs induced by a certain QoS level. In this chapter, we present an overview on our work on modeling service-oriented systems for performance prediction using the Palladio Component Model. The prediction builds upon a model of a service-based system, and evaluates this model in order to determine the expected service quality. The presented techniques allow for early quality prediction, without the need for the system being already deployed and operating. We present the integration of our prediction approach into an SLA management framework. The emerging trend to combine event-based communication and Service-Oriented Architecture (SOA) into Event-based SOA (ESOA) induces new challenges to our approach, which are topic of a special subsection.


Author(s):  
El-Alami Ayoub ◽  
Hair Abdellatif

<p>Web service composition is a concept based on the built of an abstract process, by combining multiple existing class instances, where during the execution, each service class is replaced by a concrete service, selected from several web service candidates. This approach has as an advantage generating flexible and low coupling applications, based on its conception on many elementary modules available on the web. The process of service selection during the composition is based on several axes, one of these axes is the QoS-based web service selection. The Qos or Quality of Service represent a set of parameters that characterize the non-functional web service aspect (execution time, cost, etc...). The composition of web services based on Qos, is the process which allows the selection of the web services that fulfill the user need, based on its qualities. Selected services should optimize the global QoS of the composed process, while satisfying all the constraints specified by the client in all QoS parameters. In this paper, we propose an approach based on the concept of agent system and Skyline approach to effectively select services for composition, and reducing the number of candidate services to be generated and considered in treatment. To evaluate our approach experimentally, we use a several random datasets of services with random values of qualities.</p>


Author(s):  
Laila Taher ◽  
◽  
Rawshan Basha ◽  
Hazem El Khatib ◽  
◽  
...  

Quality of Service (QoS) is an important criterion for Web service selection. The work in this paper is based on QoS Information & Computation framework (QoS-IC) [1]. QoS-IC framework supports QoS-based service selection in Service Oriented Architecture (SOA), namely Web services. In this paper, we extend the functionality of QoS-IC framework with QoS-Constraints Model. QoS-Constraints establish an association relationship between different QoS properties and are used to govern the QoS-based service selection in the underlying algorithm. We have enhanced the algorithm to accommodate QoS-Constraints and discussed an experimental evaluation based on an implementation prototype that shows how QoS-Constraints introduce efficiency to the QoS-based service selection mechanism and save valuable time for consumers.


2020 ◽  
Vol 10 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Neeti Kashyap ◽  
A. Charan Kumari ◽  
Rita Chhikara

AbstractWeb service compositions are commendable in structuring innovative applications for different Internet-based business solutions. The existing services can be reused by the other applications via the web. Due to the availability of services that can serve similar functionality, suitable Service Composition (SC) is required. There is a set of candidates for each service in SC from which a suitable candidate service is picked based on certain criteria. Quality of service (QoS) is one of the criteria to select the appropriate service. A standout amongst the most important functionality presented by services in the Internet of Things (IoT) based system is the dynamic composability. In this paper, two of the metaheuristic algorithms namely Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) are utilized to tackle QoS based service composition issues. QoS has turned into a critical issue in the management of web services because of the immense number of services that furnish similar functionality yet with various characteristics. Quality of service in service composition comprises of different non-functional factors, for example, service cost, execution time, availability, throughput, and reliability. Choosing appropriate SC for IoT based applications in order to optimize the QoS parameters with the fulfillment of user’s necessities has turned into a critical issue that is addressed in this paper. To obtain results via simulation, the PSO algorithm is used to solve the SC problem in IoT. This is further assessed and contrasted with GA. Experimental results demonstrate that GA can enhance the proficiency of solutions for SC problem in IoT. It can also help in identifying the optimal solution and also shows preferable outcomes over PSO.


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