scholarly journals An implementation of Replication Oriented Architecture (ROA) for Web Service Scalability

2021 ◽  
Vol 4 (1) ◽  
pp. 168-180
Author(s):  
PO Obilikwu ◽  
VS Terwase
Keyword(s):  
Web Services ◽  
Web Service ◽  
Confidence Level ◽  
Application Development ◽  
Development Platform ◽  
Enterprise Application ◽  
Service Scalability ◽  
Scripting Language ◽  
The Web

Web services provide application to application integration across different platforms. However, the consumption of web services generates request traffic that must be attended to by an instance of the web server without fail. To guarantee dependability of the web service, the instances of the web service are replicated as a way of scaling the web service. The Replication Oriented Architecture (ROA) has been designed and implemented using the Java Enterprise application development platform and interesting results have been obtained. Improvements in the PHP scripting language have made it a popular programming language for web and enterprise application development. In this paper, an implementation of the ROA architecture using PHP is done. The implementation is simulated on the Apache Jmeter and results compared to the results obtained in the Java implementation. The results show that both application development platforms achieve web service scalability as a quality of service (QOS) expected of a web service. In specific terms, 50.9% at 95.0% confidence level improvement in response time was achieved when PHP is used which compares favorably with 22.5% improvement at 95.0% confidence level achieved on the Java platform.

Web Services Architecture Model to Support Distributed Systems

2019 ◽  
Vol 54 (6) ◽  
Author(s):  
Sawsan Ali Hamid ◽  
Rana Alauldeen Abdalrahman ◽  
Inam Abdullah Lafta ◽  
Israa Al Barazanchi
Keyword(s):  
Web Services ◽  
Web Service ◽  
Distributed System ◽  
Modern Technology ◽  
Service Description ◽  
Architecture Model ◽  
Software Applications ◽  
Evolving Model ◽  
The Web

Recently, web services have presented a new and evolving model for constructing the distributed system. The meteoric growth of the Web over the last few years proves the efficacy of using simple protocols over the Internet as the basis for a large number of web services and applications. Web service is a modern technology of web, which can be defined as software applications with a programmatic interface based on Internet protocol. Web services became common in the applications of the web by the help of Universal, Description, Discovery and Integration; Web Service Description Language and Simple Object Access Protocol. The architecture of web services refers to a collection of conceptual components in which common sets of standard can be defined among interoperating components. Nevertheless, the existing Web service's architecture is not impervious to some challenges, such as security problems, and the quality of services. Against this backdrop, the present study will provide an overview of these issues. Therefore, it aims to propose web services architecture model to support distributed system in terms of application and issues.

scholarly journals A Cluster-Based Browsing Model For QoS-Aware Web Service Selection

2021 ◽  
Author(s):  
Kian Farsandaj
Keyword(s):  
Web Services ◽  
Web Service ◽  
Clustering Algorithm ◽  
Service Selection ◽  
Functional Requirements ◽  
Analysis Techniques ◽  
Symbolic Data ◽  
Web Service Selection ◽  
The Web

In the last decade, selecting suitable web services based on users’ requirements has become one of the major subjects in the web service domain. Any research works have been done - either based on functional requirements, or focusing more on Quality of Service (QoS) - based selection. We believe that searching is not the only way to implement the selection. Selection could also be done by browsing, or by a combination of searching and browsing. In this thesis, we propose a browsing method based on the Scatter/Gather model, which helps users gain a better understanding of the QoS value distribution of the web services and locate their desired services. Because the Scatter/Gather model uses cluster analysis techniques and web service QoS data is best represented as a vector of intervals, or more generically a vector of symbolic data, we apply for symbolic clustering algorithm and implement different variations of the Scatter/Gather model. Through our experiments on both synthetic and real datasets, we identify the most efficient ( based on the processing time) and effective implementations.

scholarly journals A Cluster-Based Browsing Model For QoS-Aware Web Service Selection

2021 ◽  
Author(s):  
Kian Farsandaj
Keyword(s):  
Web Services ◽  
Web Service ◽  
Clustering Algorithm ◽  
Service Selection ◽  
Functional Requirements ◽  
Analysis Techniques ◽  
Symbolic Data ◽  
Web Service Selection ◽  
The Web

In the last decade, selecting suitable web services based on users’ requirements has become one of the major subjects in the web service domain. Any research works have been done - either based on functional requirements, or focusing more on Quality of Service (QoS) - based selection. We believe that searching is not the only way to implement the selection. Selection could also be done by browsing, or by a combination of searching and browsing. In this thesis, we propose a browsing method based on the Scatter/Gather model, which helps users gain a better understanding of the QoS value distribution of the web services and locate their desired services. Because the Scatter/Gather model uses cluster analysis techniques and web service QoS data is best represented as a vector of intervals, or more generically a vector of symbolic data, we apply for symbolic clustering algorithm and implement different variations of the Scatter/Gather model. Through our experiments on both synthetic and real datasets, we identify the most efficient ( based on the processing time) and effective implementations.

Web Services Dependability

2010 ◽  
pp. 151-167
Author(s):  
Michael C. Jaeger ◽  
Matthias Werner
Keyword(s):  
Quality Of Service ◽  
Web Services ◽  
Web Service ◽  
Conceptual Model ◽  
Current Status ◽  
Individual Quality ◽  
Definition Of ◽  
The Web ◽  
Present Activity

This chapter presents the definition of relevant terminology and a conceptual model of the basic terms. The chapter starts with the presentation of research in the area of dependability. Based on this, Web service concepts related to the dependability are introduced. The presentation leads into a statement identifying individual quality-of-service (QoS) characteristics for forming dependable Web services. Then, the chapter discusses the current status quo in the area of QoS-aware Web services. This part is divided into three subparts: description, management, and monitoring. This also identifies ongoing efforts as well as efforts that do not show present activity. By this discussion, this chapter puts research about dependability in relation with ongoing QoS-related efforts in the Web services domain. Thus it identifies how these efforts can be combined in order to form a dependable Web services platform.

IT Application Development with Web Services

2011 ◽  
pp. 2278-2284
Author(s):  
Christos Makris ◽  
Yannis Panagis ◽  
Evangelos Sakkopoulos ◽  
Athanasios Tsakalidis
Keyword(s):  
Web Services ◽  
Web Service ◽  
Functional Characterization ◽  
Service Description ◽  
Application Development ◽  
Storage And Retrieval ◽  
Loosely Coupled ◽  
Global Consensus ◽  
Application Logic ◽  
The Web

The advent of Web Services (WS) has signaled a true revolution in the way service-oriented computing and remote procedure invocation over the Web are conducted. Web Services comprise of a set of loosely coupled specifications to coordinate process execution from distance, based on common and widely accepted Web protocols such as HTTP, FTP, and XML, and therefore, providing increased development flexibility. Since the WS Framework was built on top of those protocols, Web Services have been widely acclaimed by the Web development community and paradoxically; they have marked one of the few examples in the history of computer protocols where a global consensus has been reached. The Web Service framework consists of essentially three basic components: 1. The Web Service Description Language (WSDL), a language that allows formal functional characterization of the provided functionalities; 2. The Simple Object Access Protocol (simply SOAP from its version 1.2), a protocol that defines the format of the information interchange; and 3. The UDDI (Universal Description, Discovery and Integration) is a catalog of Web Service descriptions. All three of these components are specified using XML markup. The elegance of the WS architecture lies in the fact that every WS transaction is taking place over established Web protocols such as HTTP and FTP. As remarked in Ballinger (2003, p. 5): “A Web Service is an application logic that is accessible using Internet standards.” This very fact has accounted for the rapid and universal adoption of Web Services. This work is organized as follows: First, a review of underlying technologies and tools is presented. Consequently, existing techniques for design methodologies are described. Next, an overview of storage and retrieval techniques for Web Services is given followed by real-world applications of Web Services. We conclude with open issues and discussion.

An Agent Architecture for Qos-Based Web Service Composition Using the Skyline Algorithm

2017 ◽  
Vol 6 (3) ◽  
pp. 179 ◽  
Author(s):  
El-Alami Ayoub ◽  
Hair Abdellatif
Keyword(s):  
Web Services ◽  
Web Service ◽  
Service Composition ◽  
Service Selection ◽  
Web Service Composition ◽  
Web Service Selection ◽  
Concrete Service ◽  
The Web ◽  
Selection Of

<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>

Some Aspects of Reliability Evaluation of Multi Service Multi-Functional SOAP Based Web Services

2018 ◽  
Vol 8 (4) ◽  
pp. 24-38 ◽  
Author(s):  
Abhijit Bora ◽  
Tulshi Bezboruah
Keyword(s):  
Web Services ◽  
Web Service ◽  
Reliability Evaluation ◽  
High Load ◽  
Service Users ◽  
Load Testing ◽  
Operational Quality ◽  
Mercury Load ◽  
The Web

Reliability evaluation of multi service multi-functional SOAP based web services for high load of users is important from the perspective of operational quality of the service, users and developers. In this article, the authors have emphasized on developing a novel methodology for evaluating the reliability of web service for high load. A prototype research medical web service is considered to predict the reliability of the service by using this methodology. The authors called the service as PMedWS (Prototype Medical Web Service). They performed stress and load testing on the web service using Mercury Load Runner to study the reliability aspects against massive users. The experimental results and the statistical analysis demonstrate the applicability and effectiveness of our methodology.

scholarly journals Basic Components of Web Services Architecture: A Survey

2020 ◽  
Vol 4 (4) ◽  
pp. 26-29
Author(s):  
M.Kiran Kumar ◽  
VJST Anirudh
Keyword(s):  
Web Services ◽  
Web Service ◽  
Electronic Device ◽  
Vital Role ◽  
Service Description ◽  
Application Development ◽  
It Industry ◽  
Service Architecture ◽  
Access Protocol ◽  
The Web

Service provided by one electronic device to the other electronic device or devices is generally called as a web service. It may be a block of code that can be remotely accessed and utilized. In the present IT industry web services are playing a vital role in application development by providing a facility of using the existing modules to make up an application without coding from the scratch. This improves the productivity and reduces the overall project development cost and time. This paper provides the basic information of the components that supports the usage of web service along with the web service architecture. The components that are required for the web service architecture such as SOAP: simple object access protocol: used for establishing connection between components, UDDI (Universal Description, Discovery, and Integration):a registry that stores all the web services and WSDL: web service description language.

scholarly journals Web Service Reputation Evaluation Based on QoS Measurement

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Haiteng Zhang ◽  
Zhiqing Shao ◽  
Hong Zheng ◽  
Jie Zhai
Keyword(s):  
Quality Of Service ◽  
Web Services ◽  
Web Service ◽  
Service Provider ◽  
Evaluation Method ◽  
Quality Data ◽  
Measurement Tool ◽  
The Difference ◽  
The Web

In the early service transactions, quality of service (QoS) information was published by service provider which was not always true and credible. For better verification the trust of the QoS information was provided by the Web service. In this paper, the factual QoS running data are collected by our WS-QoS measurement tool; based on these objectivity data, an algorithm compares the difference of the offered and measured quality data of the service and gives the similarity, and then a reputation evaluation method computes the reputation level of the Web service based on the similarity. The initial implementation and experiment with three Web services' example show that this approach is feasible and these values can act as the references for subsequent consumers to select the service.

Web Service Evaluation Using Probabilistic Models

2014 ◽  
pp. 288-294
Author(s):  
S. Zimeras
Keyword(s):  
Information System ◽  
Web Services ◽  
Web Service ◽  
Software Metrics ◽  
Probabilistic Models ◽  
Web Applications ◽  
Evaluation Criteria ◽  
Service Evaluation ◽  
The Web

Information system users, administrators, and designers are all interested in performance evaluation since their goal is to obtain or provide the highest performance at the lowest cost. This goal has resulted in continuing evolution of higher performance and lower cost systems leading to today’s proliferation of workstations and personal computers, many of which have better performance than earlier supercomputers. As the variety of Web services applications (Websites) increases, it gets more important to have a set of evaluation criteria that should evaluate the performance of their effectiveness. Based on those criteria, the quality of the services that the Web applications are providing could be analysed. This work represents software metrics that could (or need) be used to quantify the quality of the information that the Web services are providing. These measures could be useful to understand problematic frameworks during the implementation of the Websites and could lead to solutions preventing those problems.

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