Showing papers on "Differentiated service published in 2015"

Problem Statement for Service Function Chaining

Abstract: This document provides an overview of the issues associated with the deployment of service functions (such as firewalls, load balancers, etc.) in large-scale environments. The term "service function chaining" is used to describe the definition and instantiation of an ordered list of instances of such service functions, and the subsequent "steering" of traffic flows through those service functions. The set of enabled service function chains reflects operator service offerings and is designed in conjunction with application delivery and service and network policy. This document also identifies several key areas that the Service Function Chaining (SFC) working group will investigate to guide its architectural and protocol work and associated documents.

Network Service Plan Design

Abstract: A technique involves modular storage of network service plan components and provisioning of same. A subset of the capabilities of a service design system can be granted to a sandbox system to enable customization of service plan offerings or other controls.

SelCSP: A Framework to Facilitate Selection of Cloud Service Providers

Abstract: With rapid technological advancements, cloud marketplace witnessed frequent emergence of new service providers with similar offerings. However, service level agreements (SLAs) , which document guaranteed quality of service levels, have not been found to be consistent among providers, even though they offer services with similar functionality. In service outsourcing environments, like cloud, the quality of service levels are of prime importance to customers, as they use third-party cloud services to store and process their clients’ data. If loss of data occurs due to an outage, the customer’s business gets affected. Therefore, the major challenge for a customer is to select an appropriate service provider to ensure guaranteed service quality. To support customers in reliably identifying ideal service provider, this work proposes a framework, SelCSP , which combines trustworthiness and competence to estimate risk of interaction. Trustworthiness is computed from personal experiences gained through direct interactions or from feedbacks related to reputations of vendors. Competence is assessed based on transparency in provider’s SLA guarantees. A case study has been presented to demonstrate the application of our approach. Experimental results validate the practicability of the proposed estimating mechanisms.

Incentive Mechanism Design for Heterogeneous Peer-to-Peer Networks: A StackelbergGame Approach

Abstract: With high scalability, high video streaming quality, and low bandwidth requirement, peer-to-peer (P2P) systems have become a popular way to exchange files and deliver multimedia content over the internet. However, current P2P systems are suffering from “free-riding” due to the peers’ selfish nature. In this paper, we propose a credit-based incentive mechanism to encourage peers to cooperate with each other in a heterogeneous network consisting of wired and wireless peers. The proposed mechanism can provide differentiated service to peers with different credits through biased resource allocation. A Stackelberg game is formulated to obtain the optimal pricing and purchasing strategies, which can jointly maximize the revenue of the uploader and the utilities of the downloaders. In particular, peers’ heterogeneity and selfish nature are taken into consideration when designing the utility functions for theStackelberg game. It is shown that the proposed resource allocation scheme is effective in providing service differentiation for peers and stimulating them to make contribution to the P2P streaming system.

Imperialist competitive algorithm with PROCLUS classifier for service time optimization in cloud computing service composition

Abstract: CSSICA is proposed to find the lowest service time for cloud composite services.PROCLUS is used to divide service providers into 3 categories based on service time.Selection probability of categories is calculated using their average service time.Utilizing achieved categories CSSICA has been able to make more conscious selections. Aiming to provide satisfying and value-added cloud composite services, suppliers put great effort into providing a large number of service providers. This goal, achieved by providing the "best" solutions, will not be guaranteed unless an efficient composite service composer is employed to choose an optimal set of required unique services (with respect to user-defined values for quality of service parameters) from the large number of provided services in the pool. Facing a wide service pool, user constraints, and a large number of required unique services in each request, the composer must solve an NP-hard problem. In this paper, CSSICA is proposed to make advances toward the lowest possible service time of composite service; in this approach, the PROCLUS classifier is used to divide cloud service providers into three categories based on total service time and assign a probability to each provider. An improved imperialist competitive algorithm is then employed to select more suitable service providers for the required unique services. Using a large real dataset, experimental and statistical studies are conducted to demonstrate that the use of clustering improved the results compared to other investigated approaches; thus, CSSICA should be considered by the composer as an efficient and scalable approach.

QoS-Aware Service Recommendation for Multi-tenant SaaS on the Cloud

Abstract: With the proliferation of cloud computing, more and more functionally equivalent cloud services with varied quality of service (QoS) have emerged. Service selection for a SaaS (Software as a Service) has become a critical issue in cloud environments, and the transition from single-tenancy to multi-tenancy has made this issue more complicated. Existing approaches suffer from low efficiency in finding optimal solutions, especially in large-scale scenarios. As a result, QoS-aware service recommendation is becoming increasingly important for selecting services for a multi-tenant SaaS that simultaneously serves multiple clients with differentiated QoS requirements. In this paper, we propose a novel service recommendation approach that largely improves the efficiency of QoS-aware service selection for multi-tenant SaaS. Our approach significantly reduces the search space of the service selection problem by selecting representative candidate services based on the diversity and similarity in tenants' QoS requirements for the SaaS. The experimental results demonstrate the effectiveness and efficiency of our approach.

PuLSaR: preference-based cloud service selection for cloud service brokers

Abstract: Over the last few years, the vast increase of cloud service offerings that are available from heterogeneous cloud vendors, has made the evaluation and selection of desired cloud services, a cumbersome task for service consumers. In that respect, there is an increasing need for user guidance and intermediation during the service selection process but also during the cloud service consumption that should always refer to the best possible choice based on user preferences. In this paper, we discuss the Preference-based cLoud Service Recommender (PuLSaR) that uses a holistic multi-criteria decision making (MCDM) approach for offering optimisation as a brokerage service. The specification and implementation details of this proposed software mechanism are thoroughly discussed while the background method used is summarised. Both method and brokerage service allow for the multi-objective assessment of cloud services in a unified way, taking into account precise and imprecise metrics and dealing with their fuzziness. We cope with the fuzziness of imprecise metrics in the sense that this approach deals with linguistically expressed preferences and cloud service characteristics that lack a fixed or precise value and entail a level of vagueness which can only be captured using the Zadeh’s Fuzzy Set Theory. Furthermore, this paper reports on a number of experiments that were conducted in order to measure PuLSaR’s performance and scalability.

Decentralized Plan-Free Semantic-Based Service Composition in Mobile Networks

Abstract: The inefficiency of one-to-one matching of user requirements to a single service has given rise to service composition Service composition allows simple services to be dynamically combined into more complex services In mobile environments, service discovery and integration involves cooperation between various service nodes where reliance on a centralized service registry introduces efficiency and single point of failure problems Plan- and workflow-based composition solutions restrict service discovery to defined abstract models Semantic similarity measurements play an important role in service integration In this paper we introduce a semantic similarity and semantic nearness service composition method The objective of our work is to free service nodes from adherence to restrictive composition plans Our work also enables compositions to succeed in dynamic environments through a decentralized solution even when nodes are unaware of nearby service nodes This paper presents a service composition solution that semantically advances composition paths towards users’ needs with each service hop while guaranteeing a user-acceptable QoS level Simulation results showcase the effectiveness of the presented solution and its compatibility with underlying service discovery methods

Quality of Experience: User's Perception about Web Services

Abstract: Web service composition enables seamless and dynamic integration of Web services. The behavior of participant Web services determines the overall performance of a composition. Therefore, it is important to choose high quality services for service composition. Existing Web service selection and discovery approaches rely on non-functional aspects (also known as quality of service or QoS), e.g., response time and availability. Though these parameters are crucial for selecting Web services, they may not reflect the user's perspective of quality. In this paper, we explore the feasibility of incorporating perceived quality from user's perspective for service selection and composition. We name such quality attributes as quality of experience (QoE). First, we propose a solution that automatically mines and identifies QoE attributes from the Web. Second, we study the application of such dynamically extracted QoE attributes for service selection. For the evaluation purpose, we collected more than 34,000 reviews from 58 different services in six domains. Our findings show that it is possible to automatically identify QoE attributes with an average precision and recall of 92 and 80 percent respectively. Our study shows that there is a strong positive correlation between QoS and QoE. Hence QoE can be used during service selection especially when QoS data are not available. Furthermore, we found 70 percent of service discovery queries indeed contain QoE attributes showing the importance of QoE attributes during the service discovery phase.

Joint location-inventory problem with differentiated service levels using critical level policy

Abstract: This paper analyzes the design of a distribution network for fast-moving items able to provide differentiated service levels in terms of product availability for two demand classes (high and low priority) using a critical level policy. The model is formulated as a MINLP with chance constraints for which we propose a heuristic to solve it. Although the heuristic does not guarantee an optimal solution, our computational experiments have shown that it provides good-quality solutions that are on average 0.8% and at worst 2.7% from the optimal solution.

Various “aaS” of everything as a service

Abstract: Numerous service models have been proposed in the form of “as a Service” or “aaS” in the past. This is especially eminent in the era of the Cloud under the term of anything as a service or everything as a service(XaaS). An unified view of XaaS can aid efficient classification of services for service registration, discovery, and composition. In view of that there lacks such an unified view which is demanded by systematic application of XaaS in the Web Service Ecosystem, towards proposing a taxonomy of “aaS”, we present in this work a collection of “aaS” based on a throughout literature survey.

The Benefit of Introducing Variability in Single-Server Queues with Application to Quality-Based Service Domains

Abstract: We propose a static service differentiation policy for a single-server queueing system serving homogeneous customers. We show that by randomly assigning customers different service grades with different service rates, the average waiting time can be reduced without affecting the mean service time. Such differentiation introduces more service time variability, but it also creates information that enables the implementation of service rate-based scheduling, which mitigates the increased variance and may even reduce the total waiting time. We provide conditions under which our static service differentiation reduces waiting, and further derive closed-form expressions for the optimal differentiation policy, which shows that both optimal service rates and allocation probabilities form geometric sequences. We illustrate our policy in the context of quality-based service domains, in which customers value service time but dislike waiting. Numerically, we find that providing differentiated service can improve system performance by 5% without any additional capacity.

Exploring customers’ zone of tolerance for B2B professional service quality

Abstract: Purpose – This paper aims to extend the current research on zone of tolerance (ZOT) and its antecedents, to the context of business-to-business (B2B) professional services from both client and service firms’ perspectives, with a modified ZOT framework including five client and service firms attributes as antecedents of desired (DSL) and adequate (ASL) service levels Prior research on zone of tolerance (ZOT) and its antecedents mostly focuses on business-to-consumer services and customers’ perspective The authors address these gaps with a modified ZOT framework with five attributes of client and service firms as antecedents of customer expectations, namely, desired service level (DSL) and adequate service level (ASL), for business-to-business (B2B) professional services Design/methodology/approach – A combination of qualitative (focus groups) and quantitative (online survey) research methods with managers of professional audit firms and their clients, using a reduced AUDITQUAL instrument with 39 items a

Toward Better Quality of Service Composition Based on a Global Social Service Network

Abstract: Automatic service composition can create new value-added services dynamically and automatically from existing services in an envisioned service-oriented architecture. However, despite considerable progress, web-scale uptake has been significantly less than initially anticipated because of several challenging issues, such as poor scalability, exponentially expanding search time in large search spaces, and the lack of service sociability caused by the isolation of services. In this paper, we propose an innovative methodology for moving from isolated service islands to a global social service network (GSSN) by developing a network model that supports service sociability. First, we propose the construction of a GSSN based on the quality of social links. We then propose an algorithm that maps the GSSN into a service cluster network to reduce the search space, and a quality-driven composition approach that enables exploitation of the service cluster network by providing workflow as a service. Finally, experimental results show that our GSSN-based approach can solve the service composition problem well, improving not only the response time but also the success rate.

Service Level Agreement(SLA) Based SaaS Cloud Management System

Abstract: Cloud computing has emerged as a new computing paradigm which has revolutionized the IT industry. It has particularly transformed the licensing of software products which are now being offered as a Service on pay-as-you-go basis. This has tremendously increased the complexity for software providers as they now have to not only manage their resources on which software are hosted but also they need to provide expected Quality of Service for customers. The Quality of Service (QoS) required by customers is guaranteed using a legal document SLA (Service Level Agreement). Current, resource management systems do not cater to the needs of a Software as a Service (SaaS) provider who requires to provide flexible and low cost services while not affecting their profit and market share. Most of them focus either at infrastructure level or at platform level. This work fills this gap by proposing a novel SLA based resource management system designed after analysing requirements of SaaS in Clouds. The proposed system is implemented using latest technologies and can scale in and out depending on updates in the user demand. We present the architectural design and evaluate the implementation with a real case study in a real Cloud environment.

Management of service compositionbased on self-controlled components

Abstract: Cloud computing and Future Internet promise a new ecosystem where everything is "as a service", reachable and connectable anywhere and anytime, everyone succeeding to get a service composition that meets his needs. But do we have the structure and the appropriate properties to design the service components and do we have the means to manage, at run-time, the personalised compositions corresponding to Service Level Agreement? In this article we introduce an entity of service composition called Self-Controlled Component (SCC), including, since the design step, functional and non-functional specifications. SCCs benefit both from the strong structure, explicit composition, and autonomic management of component-oriented programming, from the highly dynamic composition, and from the discovery capacities of service-oriented computing. Self-control mechanisms are then attached automatically to SCCs to enable autonomic application management during execution. The objective of this new concept is to provide strong Quality of Service (QoS) guarantees of composed applications. We illustrate the approach using an example called Springoo, to how in the context of a legacy application the contributions and benefits of our solution. For the management of the service composition we propose the concept of Virtual Private Service Network (VPSN) and Virtual Service Community (VSC) that allows us to model the personalised Service Level Agreement (SLA) where user requirements and provider offers converge on a QoS contract.

Platform thinking for services: the case of human resources

Abstract: This paper tests the utility of platform thinking, a design principle that has so far been applied to product development yet under-researched in service settings, for improving the value of services. A key principle of platform thinking is to balance the reuse of service components with the heterogeneity in user needs. Tuning services to specific user needs is valuable, but differentiating services when user needs are homogeneous may decrease service quality and increase cost. Using data from 676 human resource management services, this study finds that the service value is highest when the service provision is matched with the commonality potential of the services. The results indicate that using the wrong delivery channel decreases the service value which eventually could decrease the service value for an organization's external customers. These empirical findings demonstrate the relevance of platform thinking for service design and challenges conventional design criteria used for optimizing service delivery.

REST Web Service Description for Graph-Based Service Discovery

Abstract: Unlike WSDL/SOAP based services, REST services lack a widely accepted service description since it increases the coupling between clients and servers, hampering service evolution. In practice, REST services are described through informal, ad-hoc and semi-structured documents, often written in natural language, which worsens the level of coupling. Most of the few REST service descriptions currently proposed follow an operation-centric approach with unclear additional benefits for developers and consumers. We propose a service description model focused on hypermedia allowing the generation of a graph that captures state transitions in an activity layer; we also capture resource, transition, and response semantics in a semantic layer. Using graph queries we traverse the graph and facilitate service discovery and composition. The service model was implemented as Microdata-based annotations, and a JSON description. A prototype was developed using Neo4J, and a set of real Web APIs was chosen to illustrate our approach.

A Context-Aware Adaptive Web Service Composition Framework

Abstract: It is a challenge for Web service composition to perceive dynamic changes of external environment and adapt to the changes of business process rapidly. In this paper, a context-aware adaptive Web service composition framework is presented and the functions of main modules are also described in detail. In this framework, BPEL is used to describe Web service composition process and a kind of special Web service called context service is defined to support context-awareness. Agent technology is introduced to enable context service to actively perceive and process contexts of Web service and Web service composition.

Content centric networking system providing differentiated service and method of controlling data traffic in content centric networking providing differentiated service

Abstract: There is provided a content centric networking system providing a differentiated service that includes a client device that creates an interest packet, an edge router directly connected to the client device in the content centric networking system, that determines a traffic class for an interest packet on the basis of the information included in an interest packet received from the client device, and marks the determined traffic class information in association with the interest packet; and a differentiated service router, which when receiving the interest packet added with the traffic class information, stores the traffic class information in a pending interest table (PIT) and differentially transmits the data requested by the interest packet in accordance with the traffic class information.

SNA-based innovation trend analysis in software service networks

Abstract: Service networks can be considered to be open innovation systems. It has led to research on the structure of these networks, concentrating on the static network topology and its effect on innovation. However, the research misses the changes of network positions over time. In this paper, we examine the changes of nodes’ positions in a software service network. The software service network has been built from empirical data. In this network, a node represents a Software-as-a-Service (SaaS) service and a link denotes a re-use of existing software services through a new service. Our results suggest that: first, software services undergo life cycles in their network positions; second, some software services achieve to hub position in their life cycle while others a core position; and third, an innovation trend appears at service category level not just by a single service. These results imply that innovation studies should not only consider static network positions and topologies but also trends of changing positions within the network.

Method and system for automated indentification and engagement of service providers

Abstract: The current document is directed to methods and systems that identify projects for which service consumers desire service provision and identify available candidate service providers that best match various project parameters and service-provision criteria determined by the automated system. Information describing the identified candidate service providers is presented to the service consumers by the systems to allow service consumers in order to facilitate their selection of service providers and scheduling of service provision. In one described implementation, service providers are matched to stock-keeping-unit (“SKU”) identifiers and location or locations. Service providers identified in the initial SKU-and-location-based matching process are then scored and ranked according to additional criteria and constraints, with information describing the highest-ranked service candidate providers provided to service consumers for selection and scheduling.

Performance-driven dynamic service selection

Abstract: Modern software systems are increasingly built by integrating different services implemented by independent organizations and offered in an open service marketplace. In such environment, multiple providers may compete with each other by publishing services that provide the same functionality, and export the same interface, but differ in the offered QoS and in particular in the offered performance. Clients and service integrators may therefore dynamically select the most efficient services that satisfy their requirements among the competing alternatives. Service selection may be performed by clients by following different strategies, which may ultimately affect the overall quality of service invocations. In this paper, we address the problem of analyzing and comparing different service selection strategies based on a framework that supports performance estimates. We report on quantitative analyses through simulations, highlighting advantages and limitations of each strategy. Copyright © 2014 John Wiley & Sons, Ltd.

A survey on SLA-based brokering for inter-cloud computing

Abstract: Service Level Agreement (SLA), a contract between IT service provider and customer, clearly defines hardware and software parameters to ensure Quality of Service (QoS). Cloud Service Brokering (CSB) provides either API or User Interface (UI) between service subscriber and service provider which enable interoperability between several separate clouds to improve service intermediation, aggregation and arbitrage. Today, SLA-based brokering technology is emerging and has been used to ensure QoS for Inter-Cloud environment. In this paper, we surveyed and evaluated some of the latest SLA-based service brokering projects. Additionally, we discussed a high level architectural view of cloud service broker derived from these projects.

Domain-aware reputable service recommendation in heterogeneous manufacturing service ecosystem

Abstract: Networked manufacturing becomes an important manufacturing method for modern manufacturing enterprises. With the wide adoption of service-oriented architecture and cloud manufacturing, manufacturing enterprises and organisations publish their manufacturing capability, such as resources, processes and knowledge as manufacturing services. A rapidly growing manufacturing service ecosystem can be observed nowadays, which brings the information overload problem for the service selection. Thus, how to organise these services and how to recommend the reputable services become two important issues for the manufacturing service retrieval and reuse. In this paper, the service cluster method WSTPCluster, which develops the topic model based on Latent Dirichlet Allocation, is employed to cluster services into specific domains. As the service ecosystem can be modelled as a heterogeneous service network, a unified reputation propagation method URPM is proposed to calculate the reputation of services and to distinguish the reputable services in each domain. Combining WSTPCluster and URPM, domain-aware reputable service recommendation method is introduced to recommend the high reputable services in each domain for the consumers. Experiments show that this method brings a better performance both in the recommendation accuracy and in the long tail recommendation.

A Privacy-Preserving Framework for Constrained Choreographed Service Composition

Abstract: One of the major goals of Web services is to make easier their composition to form more complex services, modeled as workflows. A key role in the Web services composition is the selection of a proper service for each activity in the workflow. In general, this requires the exchange of sensitive information of users, requiring the composition, as well as of involved service providers. So far this problem has been investigated in the setting of orchestrated service composition, under the assumption of the presence of a broker coordinating the composition. However, a promising alternative approach is the one of choreography, where each service involved in the service composition has to locally manage service selection and invocation. In this paper, we propose a framework to enforce user and provider requirements in the scenario of service choreography in a privacy-preserving way, that is, without the releasing of any private information of users and providers. To achieve this result we make use of different privacy-preserving protocols. As it will be shown in the paper, the proposed solution does not implies relevant overhead.