Non-functional Quality Of Service Research Articles

Routing Protocol for MANET Based on QoS-Aware Service Composition with Dynamic Secured Broker Selection

MANET is a mobile ad hoc network with many mobile nodes communicating without a centralized module. Infrastructure-less networks make it desirable for many researchers to publish and bind multimedia services. Each node in this infrastructure-less network acts as self-organizing and re-configurable. It allows services to deploy and attain from another node over the ad hoc network. The service composition aims to provide a user’s requirement by combining different atomic services based on non-functional QoS parameters such as reliability, availability, scalability, etc. To provide service composition in MANET is challenging because of the node mobility, link failure, and topology changes, so a traditional protocol will be sufficient to obtain real-time services from mobile nodes. In this paper, the ad hoc on-demand distance vector protocol (AODV) is used and analyzed based on MANET’s QoS (Quality of Service) metrics. The QoS metrics for MANET depends on delay, bandwidth, memory capacity, network load, and packet drop. The requester node and provider node broker acts as a composer for this MANET network. The authors propose a QoS-based Dynamic Secured Broker Selection architecture (QoSDSBS) for service composition in MANET, which uses a dynamic broker and provides a secure path selection based on QoS metrics. The proposed algorithm is simulated using Network Simulator (NS2) with 53 intermediate nodes and 35 mobile nodes of area 1000 m × 1000 m. The comparative results show that the proposed architecture outperforms, with standards, the AODV protocol and affords higher scalability and a reduced network load.

A QoS Metric Approach for Web Service Pertinence for the Cloud

Background: Cloud computing is a very emerging technology today and playing an important role to provide the services through internet. Users are getting enormous benefits like high accessability of available application resources, faster time to market, fast development, deployment, lower start-up, operations cost and much more. Cloud offers us to utilize the benefits through web services. Objective: The degrading factors such as low Quality of Service, security factors, trustless and less resource management in cloud leads to service suitability issue. In service oriented computing finding an efficient QoS based web service on the web is very challenging task. Methods: A quality of service metric approach is proposed to identify the suitability of web services and ensuring the deployability in the cloud era. The suitability of web service is examined for its suitability cases (simple suitable, average suitable and best suitable) with respect to the quality of service attribute. Results: The experimental setup, first the suitability scores calculated with the essential non-functional quality of service attribute information is identified from the set of services. However, the verification process expressed using the state transition diagram. Conclusion: The proposed system is simulated using JFLAP-a java package tool and the result shows the service suitability for the cloud. In this context the efficiency of identifying service suitability for deploying in the cloud gets verified using automated theory without affecting the performance of the cloud service.

Web Service Discovery with Quality of Service (QoS) Parameters using Bayesian Belief Network

The aim of this study is to present a novel approach which uses the belief net to intelligently infer the best and most relevant web service based on the available Quality of service parameters. Service Oriented Architecture (SOA) is the discovery of relevant Web Services for a specified task is a one of the key challenges. As Web services proliferate, there is a possibility of existing more than one service with same functionalities consequently; most of service discovery method will return several services which meet user given input and output. Finding the mainly relevant and best service is very crucial for the service consumers. In this situation, the non-functional Quality of Service (QoS) parameters present in the service description provided by the service provider play a major responsibility.

A view-based monitoring for usage control in web services

Quality of service (QoS) can be a critical element for achieving the business goals of a service provider, and accepting a service by the customer. The criticality is more pronounced when the service provider handles the non-functional QoS attribute of privacy, i.e., privacy related to the customer's personal data. In this regard, the customer needs some guarantee(s) from the service provider about confidentiality management, leading to overall quality characterization of the provided service. A service level agreement (SLA) is primarily intended to specify (in terms of clauses) the level of such non-functional QoS delivered to the customer. The aim is to provide customers with tools that show the fulfillment of QoS guarantees, through SLA monitoring process. In this paper, we address the problem of usage control of private data in service based applications ensuring end-to-end QoS capabilities. We propose a query containment based approach to support the monitoring of privacy-aware SLA compliance, that spells out a customer's privacy rights, and shows how the customer's private information must be handled by a Web service provider. We introduce the private data usage flow model upon which the monitoring is performed to observe the data usage flow, and capture the privacy vulnerabilities that may lead to non-compliance. The model is built on top of (i) properties and time-related privacy requirements to be monitored, and (ii) a set of identified privacy violations. As proof of concept, a privacy aware SLA monitoring system, which is an easy-to-use, and efficient tool for observing the dynamic private data usage flow is developed. Experiment results indicate the relevance and applicability of the proposed approach.

A Service Broker Model for Cloud based Render Farm Selection

Cloud computing is gaining popularity in the 3D Animation industry for rendering the 3D images. Rendering is an inevitable task in creating the 3d animated scenes. It is a process where the scene files to be animated is read and converted into 3D photorealistic images automatically. Since it is a computationally intensive task, this process consumes the majority of the time taken for 3D images production. As the scene files could be processed in parallel, clusters of computers called render farms can be used to speed up the rendering process. The advantage of using Cloud based render farms is that it is scalable and can be availed on demand. One of the important challenges faced by the 3D studios is the comparison and selection of the cloud based render farm service provider who could satisfy their functional and the non functional Quality of Service (QoS) requirements. In this paper we propose, a frame work for Cloud Service Broker (CSB) responsible for the selection and provision of the cloud based render farm. The Cloud Service Broker matches the functional and the non functional Quality of Service requirements (QoS) of the user with the service offerings of the render farm service providers and helps the user in selecting the right service provider using an aggregate utility function. The CSB also facilitates the process of Service Level Agreement (SLA) negotiation and monitoring by the third party monitoring services.

Reliable Execution Based on CPN and Skyline Optimization for Web Service Composition

With development of SOA, the complex problem can be solved by combining available individual services and ordering them to best suit user's requirements. Web services composition is widely used in business environment. With the features of inherent autonomy and heterogeneity for component web services, it is difficult to predict the behavior of the overall composite service. Therefore, transactional properties and nonfunctional quality of service (QoS) properties are crucial for selecting the web services to take part in the composition. Transactional properties ensure reliability of composite Web service, and QoS properties can identify the best candidate web services from a set of functionally equivalent services. In this paper we define a Colored Petri Net (CPN) model which involves transactional properties of web services in the composition process. To ensure reliable and correct execution, unfolding processes of the CPN are followed. The execution of transactional composition Web service (TCWS) is formalized by CPN properties. To identify the best services of QoS properties from candidate service sets formed in the TCSW-CPN, we use skyline computation to retrieve dominant Web service. It can overcome that the reduction of individual scores to an overall similarity leads to significant information loss. We evaluate our approach experimentally using both real and synthetically generated datasets.

Admission control policies for a multi-class QoS-aware service oriented architecture

In the service computing paradigm, a service broker can build new applications by composing network-accessible services offered by loosely coupled independent providers. In this paper, we address the problem of providing a service broker, which offers to prospective users a composite service with a range of different Quality of Service (QoS) classes, with a forward-looking admission control policy based on Markov Decision Processes (MDP). This mechanism allows the broker to decide whether to accept or reject a new potential user in such a way to maximize its gain while guaranteeing non-functional QoS requirements to its already admitted users. We model the broker using a continuous-time MDP and consider various techniques suitable to solve both infinite-horizon and finitehorizon MDPs. To assess the effectiveness of the MDP-based admission control for the service broker, we present simulation results where we compare the optimal decisions obtained by the analytical solution of the MDP with other admission control policies. To deal with large problem instances, we also propose a heuristic policy for the MDP solution.

A user centric service-oriented modeling approach

With rapid development of service-oriented architecture and cloud computing, web services have been widely employed on the Internet. Quality of Service (QoS) is a very important criterion for service consumers to measure and select services. The selection of web services with respect to non-functional QoS criteria can be considered as a Multiple Criteria Decision Making (MCDM) problem when multiple consumers need to share a number of services. This paper describes a new user centric service-oriented modeling approach which is featured by integrating fuzzy Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) and Service Component Architecture (SCA) to facilitate web service selection and composition and to effectively satisfy a group of service consumers' subjective requirements and preferences in the dynamic environment. The main contribution of this method is able to translate a group of users' fuzzy requirements to services as well as model different levels of hardware and software as services to meet the requirements. We also design a simulated environment that includes 8*8 LED matrix on a circuit board that corresponds to an office with different appliances to demonstrate the dynamic service selection and binding. The simulation is used to assess the computational efficiency of the fuzzy TOPSIS method and the effectiveness of the proposed system.

A QoS-aware Method for Web Services Discovery

The non-functional QoS (quality of service) information helps us to select a proper Web-service from the web applications, by using component services such as UDDI[1](Universal Description, Discovery, and Integration) and MDS(Monitoring and Discovery System). MDS is a suite of web services to monitor and discover resources and service on Grids, but MDS only based on function aspects. This paper studies on an approach to provide the QoS information and a discovery model by using MDS and gives a system deployment and implementation plan. The simulation results show that the method is effective in service discovery.

Combining subjective and objective QoS factors for personalized web service selection

Abstract Web service is an emerging Internet technology to dynamically describe, discover and communicate. According to the Web Service Architecture (WSA) published by W3C, users can find services through the repository Universal Description, Discovery and Integration (UDDI). However, the UDDI may find many web services with similar functions without considering the nonfunctional quality of service (QoS) information. Under such circumstances, users may have difficulty deciding which service is suitable. This paper proposes a fuzzy-based UDDI with QoS support. Unlike many similar researches, the proposed method tries to consider not only the objective factors described by service providers but also the subjective information with trustability evaluations from users who use those services. Genetic algorithm (GA) is adapted to learn user preferences, and fuzzy logic is applied for making decisions. With a fuzzy query interface to input subjective and objective factors, users can determine the most suitable web service for personal use.