QoS Based Framework for Effective Web Services in Cloud Computing

International Journal of Computer Applications, 2015

Web services provides a mechanism to aggregate multiple services into one composite services. It select services based on functional and non-functional attributes of services according to the applied user constraints. Abstract Service Ontology is a framework for optimized service selection which is formalized and developed by using OWL2-RL language. Abstract Service Ontology consists some players which are Service Provider, Information Agent, Ontology Provider, and Composer. Service Provider provides atomic concrete services, Ontology Provider defines offered functionalities and the composer query ontologies to select and execute the best conformed composite services. Request model, Objects Values conformation model and Constraint selection model aims to services selection among best affected objects services. Service selection from constraint model by using SPARQL query can be done, which follows preprocessing, conforming objects values identification and conforming composite services identification. XML files to structure Request model of the user in which requested abstract services list, its affected objects and user's constraints are there for preprocessing. Conforming object values identification determines instances of affected objects. Constraint selection model locates services which relates to the value of SPARQL query 1. Models are used for efficient and improved selection of service. Some Bio-Inspired Optimization algorithms and integration in modules can be applied and its results, efficiency can be improved and execution time can be reduced.

2005

Quality of Service (QoS) support in web services plays a great role for the success of this emerging technology. In this paper, we present a QoS brokerbased architecture for web services. The main goal of the architecture is to support the client in selecting web services based on his/her required QoS. To achieve this goal, we propose a two-phase verification technique that is performed by a third party broker. The first phase consists of syntactic and semantic verification of the service interface description including the QoS parameters description. The second phase consists of applying a measurement technique to compute the QoS metrics stated in the service interface and compares their values with the claimed one. This is used to verify the conformity of a web service from the QoS point of view (QoS testing). A methodological approach to generate QoS test cases, as input to QoS verification is used. We have implemented a prototype that includes the verification and certification components of the broker. We performed experiments to evaluate the importance of verification and certification features in the selection process using real web services.

Journal of Network and Computer Applications, 2008

This work proposes a Web Service (WS) discovery model in which the functional and nonfunctional requirements are taken into account during service discovery. The proposed infrastructure includes a set of services and tools to support an integrated WS discovery and selection solution. A mechanism is introduced that supports three different functional policies. It is able to take advantage of quality information located into a Web Service description language description file that might be located in a proprietary universal description, discovery and integration registry server or in an independent URL. Moreover, it implements a database supported WS intermediary (Broker) that it is also possible to store quality of service (QoS) information for WSs. A selection module is also presented that delivers the WS that maximizes the value of QoS characteristics among others with the same functionality. An experimental prototype is presented and evaluated in the scenario of air ticket issuing WS selection. r

2019

Web Services in ample amount lying over the net are found similar in functionality varying in QoS (Quality of Services). Various methods and techniques have been proposed by researchers in order to get the most favoured and best-suited candidate services to be able to become the part of the final outcome which is called composite web service. Quality of Service has emerged as an important tool playing decisive role while selecting best candidate web Services as well as Composite Web Services. Undoubtedly, the technique of web services composition is the key property of service-orientation helps create new as well as advanced level services reusing the existing ones. In a distributed environment, services with no quality guarantees, have adverse impact on the final composition outcome. In their efforts to select the most favoured candidate services to be used for the composition, scholars while proposing new composition techniques relied on either Users’ provided feedbacks or Provide...

2008

With the widespread proliferation of web services, the demand on highly reliable and available services increases to satisfy business and personal needs. As the number of functionally similar web service increases on the Internet, Quality of Service (QoS) based web service selection and composition has gained much attention. However, the existing architectures for runtime service composition requires discovery of all functionally similar services, which consumes too much time. Instead, it can be possible to discover only those services which are highly reliable and thus included in composition. This issue can be solved by introducing a broker based architecture for automated dynamic web service discovery and composition in which the composition operation accepts as input a set optimized services along with their QoS specifications. The proposed architecture is able to reduce the composition time by performing optimized selection of services using Local Selection and Local Optimization (LSLO) approach during service composition. The architecture is fault tolerant and ensures improved reputation prediction accuracy of selected services using Mixed Opinion based Reputation Prediction (MORP) approach. In this paper, a comparative analysis is also performed on the basis of set of criterion to analyze the existing dynamic web service discovery and composition architectures for their strengths and weaknesses.

In today’s scenario, most of the organizations provide the services through the web. This makes the web service an important research area. In addition, early design and building web services, it is necessary to concentrate on the quality of web services. Performance is an important quality attributes that to be considered during the designing of web services. The expected performance can be achieved by proper scheduling of resources and scalability of the system. Scalability is a desirable attribute of a process computer system or network. Poor scalability can result in lacking system performance. Hence, in this paper, we have reviewed the literature available for the quality attributes of performance and scalability and identified the issues that affect the quality attributes related to Web Services.

Web service plays an important role in e-business and e-commerce applications. A web service applications are interoperable and can work on any platform, large scale distributed systems can be established easily. The selection of most suitable web service is very crucial for successful execution of applications due to the rapid growth of web service providers in the Internet. Researchers have proposed various techniques for service discovery like ranking and clustering the web services.

This work proposes a Web Service (WS) discovery model in which the functional and non-functional requirements are taken into account during service discovery. The proposed infrastructure includes a set of services and tools to support an integrated WS discovery and selection solution. A mechanism is introduced that supports three different functional policies. It is able to take advantage of quality information located into a WSDL description file that might be located in a proprietary UDDI registry server or in an independent URL. Moreover it implements a database supported WS intermediary (Broker) that it is also possible to store QoS information for Web Services. A selection module is also presented that delivers the WS that maximizes the value of QoS characteristics among others with the same functionality. An experimental prototype is presented and evaluated in the scenario of air ticket issuing WS selection.

2004

As the web services technology become more fashionable, we will meet with the need for systems able to guarantee a given level of quality of service (QoS). This need is caused by factors like response time, availability, or throughput, which are variables completely unpredictable when using Internet. In addition, when a client can use multiple providers, we need a system to automatically qualify, select, and use a concrete provider. This paper will show a new technique that allows creating web services with QoS features. This new technique is based on the virtualization of the real web services used to serve the client requests. What we propose is to create new virtual web services that will be the ones invoked by the clients. On the server side, the real web services are invoked in order to accomplish the primary invocation.

… , 2008. ICCCE 2008. …, 2008

As Web services are becoming omnipresent on the Web, quality of Web services (QoWS) support and management is becoming a hot research topic. Several frameworks for Web service selection have been proposed to support clients in selecting suitable Web services. They are very often based on a middle-tier component to make the selection decision. These solutions suffer very often from scalability problems. To deal with this issue, we propose in this paper a new architecture for Web service selection based on a federation of cooperative brokers. Each broker of the federation manages the Web services within its domain and cooperates with its peers by exchanging information about Web services, such as reputation and QoS, to better serve client requests. We have developed a prototype of the architecture and we have conducted experiments using three broker selection policies mainly "random", "round-robin", and "cooperative brokers" to evaluate the degree of fulfillment of clients' requests. Preliminary results show that the best results are obtained by using the cooperative brokers' policy.