Taking value-networks to the cloud services: security services, semantics and service level agreements

Cloud services have become an emerging solution for organizations striving to address today’s need for agility, but little research has addressed transitioning multiple, collaborating organizations to what can be referred to as a “value-network cloud.” We know that organizations adopting cloud services to execute business processes must concomitantly reconfigure their security solutions for their integrated intra- and inter-organizational collaborations. We address the question, “What is needed to make it possible for an entire value-network to take secure, collaborative business process executions to the cloud?” Future value-network cloud solutions will require completely new security approaches that will leverage contracted brokering solutions operating as part of the cloud solution. We view value-network cloud security service provisioning as a bundle decision characterized by a mix of communication patterns relevant to intra- and inter-enterprise collaboration. We propose a cloud service broker model—using semantics and SLA based middleware—to serve as a trusted interface between the enterprise, cloud service providers and other organizations collaborating in a value-network. The approach enables IT governance for value-network cloud services. The architectural requirements adapt design principles for infrastructure management tailored from approaches to how business cartels historically conducted secure business dealings.     

URL: A unified reinforcement learning approach for autonomic cloud management

Cloud computing is emerging as an increasingly important service-oriented computing paradigm. Management is a key to providing accurate service availability and performance data, as well as enabling real-time provisioning that automatically provides the capacity needed to meet service demands. In this paper, we present a unified reinforcement learning approach, namely URL, to automate the configuration processes of virtualized machines and appliances running in the virtual machines. The approach lends itself to the application of real-time autoconfiguration of clouds. It also makes it possible to adapt the VM resource budget and appliance parameter settings to the cloud dynamics and the changing workload to provide service quality assurance. In particular, the approach has the flexibility to make a good trade-off between system-wide utilization objectives and appliance-specific SLA optimization goals. Experimental results on Xen VMs with various workloads demonstrate the effectiveness of the approach. It can drive the system into an optimal or near-optimal configuration setting in a few trial-and-error iterations.     

Formulating and managing viable SLAs in cloud computing from a small to medium service provider's viewpoint: A state-of-the-art review

In today's competitive world, service providers need to be customer-focused and proactive in their marketing strategies to create consumer awareness of their services. Cloud computing provides an open and ubiquitous computing feature in which a large random number of consumers can interact with providers and request services. In such an environment, there is a need for intelligent and efficient methods that increase confidence in the successful achievement of business requirements. One such method is the Service Level Agreement (SLA), which is comprised of service objectives, business terms, service relations, obligations and the possible action to be taken in the case of SLA violation. Most of the emphasis in the literature has, until now, been on the formation of meaningful SLAs by service consumers, through which their requirements will be met. However, in an increasingly competitive market based on the cloud environment, service providers too need a framework that will form a viable SLA, predict possible SLA violations before they occur, and generate early warning alarms that flag a potential lack of resources. This is because when a provider and a consumer commit to an SLA, the service provider is bound to reserve the agreed amount of resources for the entire period of that agreement – whether the consumer uses them or not. It is therefore very important for cloud providers to accurately predict the likely resource usage for a particular consumer and to formulate an appropriate SLA before finalizing an agreement. This problem is more important for a small to medium cloud service provider which has limited resources that must be utilized in the best possible way to generate maximum revenue. A viable SLA in cloud computing is one that intelligently helps the service provider to determine the amount of resources to offer to a requesting consumer, and there are number of studies on SLA management in the literature. The aim of this paper is two-fold. First, it presents a comprehensive overview of existing state-of-the-art SLA management approaches in cloud computing, and their features and shortcomings in creating viable SLAs from the service provider's viewpoint. From a thorough analysis, we observe that the lack of a viable SLA management framework renders a service provider unable to make wise decisions in forming an SLA, which could lead to service violations and violation penalties. To fill this gap, our second contribution is the proposal of the Optimized Personalized Viable SLA (OPV-SLA) framework which assists a service provider to form a viable SLA and start managing SLA violation before an SLA is formed and executed. The framework also assists a service provider to make an optimal decision in service formation and allocate the appropriate amount of marginal resources. We demonstrate the applicability of our framework in forming viable SLAs through experiments. From the evaluative results, we observe that our framework helps a service provider to form viable SLAs and later to manage them to effectively minimize possible service violation and penalties.     

云计算背景下企业IT 决策机制框架

云计算的不同应用水平会在不同程度影响企业的IT决策,相应的IT决策机制也会随之发生变化．本文深入分析了云计算的三层服务模式对IT决策的影响,由此提出了基于云计算背景的IT决策机制框架．并通过国外成功实施云计算的企业案例分析并验证本文得出的IT决策机制框架．本文不仅对以往的IT决策机制框架的基础上加入了IT服务模式维度,同时也为云计算在企业中的应用提供了制度框架．     

An SLA-based cloud computing that facilitates resource allocation in the distributed data centers of a cloud provider

The number of cloud service users has increased worldwide, and cloud service providers have been deploying and operating data centers to serve the globally distributed cloud users. The resource capacity of a data center is limited, so distributing the load to global data centers will be effective in providing stable services. Another issue in cloud computing is the need for providers to guarantee the service level agreements (SLAs) established with consumers. Whereas various load balancing algorithms have been developed, it is necessary to avoid SLA violations (e.g., service response time) when a cloud provider allocates the load to data centers geographically distributed across the world. Considering load balancing and guaranteed SLA, therefore, this paper proposes an SLA-based cloud computing framework to facilitate resource allocation that takes into account the workload and geographical location of distributed data centers. The contributions of this paper include: (1) the design of a cloud computing framework that includes an automated SLA negotiation mechanism and a workload- and location-aware resource allocation scheme (WLARA), and (2) the implementation of an agent-based cloud testbed of the proposed framework. Using the testbed, experiments were conducted to compare the proposed schemes with related approaches. Empirical results show that the proposed WLARA performs better than other related approaches (e.g., round robin, greedy, and manual allocation) in terms of SLA violations and the provider’s profits. We also show that using the automated SLA negotiation mechanism supports providers in earning higher profits.     

云环境下基于SLA的优化资源分配研究

针对云计算环境下如何高效分配资源,实现资源供应者利润最大化这一难题,提出了一种基于服务级别协议（SLA）的动态云资源分配策略。该策略通过将SLA中的计算力、网络带宽、数据存储等属性作为优化参数,构造了一种服务请求与资源的映射模型,同时设计相应的效用函数,并结合改进的与模拟退火算法相融合的混合粒子群算法（SA-PSO）,实现云环境下的优化资源分配。实验分析结果表明,基于SLA参数的SA-PSO算法具有更好的全局最优值,在给定虚拟资源相同情况下,调用该算法完成用户任务实现的利润更高。     

Cloud Computing: Distributed Internet Computing for IT and Scientific Research

Cloud computing is a disruptive technology with profound implications not only for Internet services but also for the IT sector as a whole. Its emergence promises to streamline the on-demand provisioning of software, hardware, and data as a service, achieving economies of scale in IT solutions' deployment and operation. This issue's articles tackle topics including architecture and management of cloud computing infrastructures, SaaS and IaaS applications, discovery of services and data in cloud computing infrastructures, and cross-platform interoperability. Still, several outstanding issues exist, particularly related to SLAs, security and privacy, and power efficiency. Other open issues include ownership, data transfer bottlenecks, performance unpredictability, reliability, and software licensing issues. Finally, hosted applications' business models must show a clear pathway to monetizing cloud computing. Several companies have already built Internet consumer services such as search, social networking, Web email, and online commerce that use cloud computing infrastructure. Above all, cloud computing's still unknown "killer application" will determine many of the challenges and the solutions we must develop to make this technology work in practice.     

云环境下基于服务等级协议的信任评估模型

针对用户在交互过程中对云服务商缺乏信任的问题,提出了一个基于服务等级协议(SLA)的云计算信任模型。在该模型中,云服务商在向服务中心--可信的第三方平台注册时,首先提交自身的实力评估报告,说明其实力、运营、技术及提供的服务属性等,服务中心根据相关的评价标准对该云服务商进行评估,得到系统信任;其次把系统信任引入到传统的声誉机制中,把系统信任、直接信任和间接信任作为评估一个云服务提供商的三个重要因素,并计算出云服务商的综合信任度;最后用户根据云服务商提供的服务和综合信任度与其进行SLA协商,确定最终交互对象,屏蔽掉不诚实或信誉较低的云服务商。实验结果表明,在基于服务等级协议的信任模型中,由于引入了系统信任,云服务商综合信誉的获得更全面准确、有效地防止了云服务商的不诚信行为,提高了交互的成功率。     

Will cloud computing make the Information Technology (IT) department obsolete?

The rapid adoption and growth of cloud computing is creating unprecedented change in the manner in which IT services are procured, managed, and deployed. Cloud computing is forcing firms to rethink traditional IT governance practices while raising new and fundamental questions for scholars and practitioners. This paper identifies the major areas of change and highlights governance issues that arise with the adoption of cloud computing. The focus of this paper is on the organizational impact on IT governance under cloud computing. The paper posits (1) that successful IT departments under cloud computing will transform into new roles that address internal customer‐facing issues and external cloud‐facing issues, (2) firms that mitigate information asymmetry under cloud computing will show higher firm performance, and (3) firms that offer superior cloud‐sourced IT service attributes of internal prices, quality, variety, and competition in the cloud will show higher firm performance.     

QoS约束的云经济资源管理模型研究

提供用户满意的、具有QoS约束的云计算应用是云计算面临的一大难题。提出了以商品市场为原型的云计算经济资源管理模型,其通过云用户与供应商的SLA协商,实现应用服务层QoS到资源设备层QoS的映射,最后利用效用函数的管理策略实现资源的优化调度。     

Scalable risk assessment method for cloud computing using game theory (CCRAM)

Cloud computing is one of the most popular information processing concepts of today's IT world. The security of the cloud computing is complicated because each service model uses different infrastructure elements. Current security risk assessment models generally cannot be applied to cloud computing systems that change their states very rapidly. In this work, a scalable security risk assessment model has been proposed for cloud computing as a solution of this problem using game theory. Using this method, we can evaluate whether the risk in the system should be fixed by cloud provider or tenant of the system.     

A survey on security challenges in cloud computing: issues,threats, and solutions

Cloud computing has gained huge attention over the past decades because of continuously increasing demands. There are several advantages to organizations moving toward cloud-based data storage solutions. These include simplified IT infrastructure and management, remote access from effectively anywhere in the world with a stable Internet connection and the cost efficiencies that cloud computing can bring. The associated security and privacy challenges in cloud require further exploration. Researchers from academia, industry, and standards organizations have provided potential solutions to these challenges in the previously published studies. The narrative review presented in this survey provides cloud security issues and requirements, identified threats, and known vulnerabilities. In fact, this work aims to analyze the different components of cloud computing as well as present security and privacy problems that these systems face. Moreover, this work presents new classification of recent security solutions that exist in this area. Additionally, this survey introduced various types of security threats which are threatening cloud computing services and also discussed open issues and propose future directions. This paper will focus and explore a detailed knowledge about the security challenges that are faced by cloud entities such as cloud service provider, the data owner, and cloud user.

     

An adaptive resource management scheme in cloud computing

There are various significant issues in resource allocation, such as maximum computing performance and green computing, which have attracted researchers’ attention recently. Therefore, how to accomplish tasks with the lowest cost has become an important issue, especially considering the rate at which the resources on the Earth are being used. The goal of this research is to design a sub-optimal resource allocation system in a cloud computing environment. A prediction mechanism is realized by using support vector regressions (SVRs) to estimate the number of resource utilization according to the SLA of each process, and the resources are redistributed based on the current status of all virtual machines installed in physical machines. Notably, a resource dispatch mechanism using genetic algorithms (GAs) is proposed in this study to determine the reallocation of resources. The experimental results show that the proposed scheme achieves an effective configuration via reaching an agreement between the utilization of resources within physical machines monitored by a physical machine monitor and service level agreements (SLA) between virtual machines operators and a cloud services provider. In addition, our proposed mechanism can fully utilize hardware resources and maintain desirable performance in the cloud environment.     

服务水平协议感知的云中心利润最大化资源配置

针对云计算中心优化资源配置以实现利润最大化的问题,提出基于服务水平协议(SLA)感知的云中心服务器数量和运行速率优化的分析模型,同时考虑了云中心能耗成本、服务器租用成本、用户等待时间、SLA违规惩罚等重要因素。通过数值仿真分析了服务器数量、运行速率变化对云中心利润的影响。数值仿真结果表明:在请求速率固定时,通过优化服务器数量、运行速率可使云中心获得最大利润;而随着请求速率的增加,优化服务器数量和运行速率将会使云中心利润呈线性增长。分析结果可为云服务提供商获得更好的收益提供参考方法。     

A benefit-aware on-demand provisioning approach for multi-tier applications in cloud computing

Dynamic resource provisioning is a challenging technique to meet the service level agreement (SLA) requirements of multi-tier applications in virtualization-based cloud computing. Prior efforts have addressed this challenge based on either a cost-oblivious approach or a cost-aware approach. However, both approaches may suffer frequent SLA violations under flash crowd conditions. Because they ignore the benefit gained that a multi-tier application continuously guarantees the SLA in the new configuration. In this paper, we propose a benefit-aware approach with feedback control theory to solve this problem. Experimental results based on live workload traces show that our approach can reduce resource provisioning cost by as much as 30% compared with a costoblivious approach, and can effectively reduce SLA violations compared with a cost-aware approach.     

企业云服务体系结构设计框架

云计算应用和企业私有云建设不是简单的虚拟化和传统意义上的主机托管.为了着力提升企业信息资源的重用性、敏捷性和快速服务响应水平,以国防部体系结构框架DoDAF V2.0的服务视图模型为主体,提出一个基于面向服务体系结构（SOA）的企业云服务体系结构设计框架.通过服务视图模型间约束关系的研究和融合云计算模式的面向服务体系解析,建立相应的企业云服务体系结构设计规范和企业云计算应用实施环境.最后,提出了一个基于松耦合SOA的云应用解决方案,从而支持企业云服务体系结构设计和云计算应用技术实施.     

基于传统数据中心浅析云计算数据中心基础环境

自从Google提出云计算的概念后,云就受到了全世界的瞩目和IT业界的高度重视。由于云计算对用户终端配置要求极低,使用起来很方便,用户可以直接编辑存储在云端的文档,随时与朋友分享信息,几乎所有的应用服务都由云端提供,云端的运维管理交给专业的团队来完成,用户可以不用再担心自己软件的版本是否需要更新。也不必为软件或文档染上病毒而发愁,正如2009年,美国（（Business Week））杂志报道：“云计算即将引爆商业革命,改写IT业界的游戏规则……”。     

Estimating the impact of cloud computing on firm performance: An empirical investigation of listed firms

This study empirically investigates the economic impact of cloud service adoption on firm performance. We exploit the difference-in-differences models coupled with propensity score-based matching to estimate the performance effect of cloud computing on worldwide listed firms that adopted cloud service during 2010–2016. The results indicate that cloud computing has a significant and positive impact on the profitability and market value of listed firms with varying degrees in both short and long time periods. In addition, the magnitude of the performance effect varies with firm size and industry type. This research contributes to empirical examination on the economic values of IT investments.     

云计算中的主机安全技术

云计算作为IT行业的一个新兴的领域,短时间内就展示出了强大的活力。越来越多的公司建立了自己的云计算中心或者数据中心。随着数据和计算能力的集中化,云计算中的主机安全问题越来越被关注。本文先简单地介绍了云计算的概念和服务模式,然后根据云计算环境的特点,探讨云计算的主机安全问题和相关技术,最后探讨在云计算平台的环境下,实现主机安全的技术解决方案。