Private cloud for collaboration and e-Learning services: from IaaS to SaaS

The idea behind cloud computing is to deliver Infrastructure-, Platform- and Software-as-a-Service (IaaS, PaaS and SaaS) over the Internet on an easy pay-per-use business model. The Hochschule Furtwangen University (HFU) is running their own private cloud infrastructure, called Cloud Infrastructure and Application CloudIA. The targeted users of the CloudIA project are HFU staff and students running e-Learning applications, and external people for collaboration purposes. Therefore, in this paper, we introduce our work in building a private cloud. More specifically, this paper shows how our cloud offerings in each of the cloud service models, i.e. IaaS, PaaS and SaaS, address the requirements and needs of e-Learning and collaboration in an university environment.     

一种面向PaaS的实例级应用动态更新技术

云计算是当前信息技术的重要技术领域,而平台即服务(PaaS)已成为业界研究的热点之一。PaaS平台为用户提供高可用、高可扩展的应用开发、部署和运行环境。然而当部署到云端的应用需要不断更新以修复错误、增加功能时,当前主流PaaS平台却因缺乏对应用在线更新的有效支持而削弱了其自身的高可用特性。为解决该问题,提出一个面向PaaS平台的动态更新技术框架。基于现有软件动态更新技术的研究,通过对PaaS平台中应用的事务管理、动态依赖管理、版本管理等机制的扩展,为PaaS平台提供运行时实例级的应用动态更新支撑,并在Cloud Foundry上进行实现和实验,结果证明了该动态更新技术的有效性。     

Software-as-a-service （SaaS）： perspectives and challenges

Software-as-a-service （SaaS） has received significant attention recently as one of three principal components of cloud computing, and it often deals with applications that run on top of a platform-as-a-service （PaaS） that in turn runs on top of infrastructure-as-a-service （IaaS）. This paper provides an overview of SaaS including its architecture and major technical issues such as customization, multi-tenancy architecture, redun- dancy and recovery mechanisms, and scalability. Specifically, a SaaS system can have architecture relating to a database-oriented approach, middleware-oriented approach, service-oriented approach, or PaaS-oriented ap- proach. Various SaaS customization strategies can be used from light customization with manual coding to heavy customization where the SaaS system and its underlying PaaS systems are customized together. Multi-tenancy architecture is an important feature of a SaaS and various trade-offs including security isolation, performance, and engineering effort need to be considered. It is important for a SaaS system to have multi-level redundancy and recovery mechanisms, and the SaaS system needs to coordinate these with the underlying PaaS system. Finally, SaaS scalability mechanisms include a multi-level architecture with load balancers, automated data migration, and software design strategies.     

一种物流云系统的架构方法

为实现物流领域云服务,满足物流产业相关企业对云服务个性化,快速开发和多样化应用的需求,在云计算机应用架构的原理基础上,根据现代物流企业对物流云服务的特点,提出了一种集底层软硬件管理平台、云服务应用环境平台、云服务开发平台等为一体的物流云PaaS平台架构.讨论和分析了该架构的设计原理和实施细节,为进一步搭建物流领域多样化的SaaS应用提供了快速开发、统一协调和调度的平台,进而满足用户“一站式”个性化服务需求.     

PERSIST: Policy-Based Data Management Middleware for Multi-Tenant SaaS Leveraging Federated Cloud Storage

NoSQL data stores are often combined to address different requirements within the same application. The implication of this trend is particularly important and relevant in the context of multi-tenant SaaS applications where tenants commonly have different storage- and privacy-related requirements and thus they desire to customize the storage setup according to their specific needs. Consequently, application developers are increasingly combining storage resources: on-premise and public cloud resources in a hybrid cloud setup, different external public cloud storage resources and providers in a federated cloud storage setup, etc. The consequences of these trends are twofold: (i) application developers and SaaS providers have to deal with heterogeneous technologies, different APIs, and implement complex storage logic (to address different requirements of tenants), all within the application layer; and (ii) storage architectures have become less rigid, and techniques are required to flexibly change the storage configuration of running applications, up to the level of individual service requests. To address these challenges, we present PERSIST, a middleware architecture that (i) externalizes the complexity of a federated cloud storage architecture and the complex storage logic from the SaaS application to storage policies, allows tenants to enforce different storage- and privacy-related requirements at a fine-grained level; and (ii) supports the dynamic (re)configurability of the underlying federated cloud storage architecture. Application-specific policies can be customized by individual tenants at run time, and PERSIST offers support for run-time cross-provider polyglot persistence and the confidentiality of sensitive data through encryption. We have validated PERSIST in a working prototype implementation. Our extensive evaluation efforts show (i) the accomplished reduction in the required development effort to support complex storage policies, (ii) the reduction in cost/effort to change the data storage architecture itself, and finally (iii) the acceptability of the performance overhead (around 6% for insert, and 2% for read, update and delete transactions).     

互联网网站整体迁移到云计算平台的研究与应用

云计算平台可作为一种基于互联网的、动态可伸缩的、以服务方式提供计算资源的全新计算模式,在今后各企业的IT架构中将占据重要的位置.介绍了IT企业如何充分利用Amazon的弹性云的各种资源,整体迁移大多数企业内部应用和产品到云计算平台、快速灵活的配置企业各种资源,并利用云计算平台,最大化利用资源的同时,又能及时响应限制于IT设施投入的机遇.同时分析了迁移所涉及到的服务架构调整、相关资源利用和安全性稳定性等问题.     

The Building Blocks of a PaaS

Traditional cloud computing providers enable developers to program and deploy applications in the cloud by using platform as a service (PaaS) providers. Despite the benefits of such an approach, this service model usually comes with a high level of the lock in effect into the service provider. The lock in effect occurs when a software developer needs to change its cloud provider. When this happens, it usually means a major application rewrite, specific for the new PaaS. This paper details the initial results of a project whose goal is to build a PaaS where vendor lock in does not occur. With this PaaS, developers wishing to deploy their applications into the cloud may continue to program using their usual development environments. There are no necessary changes required to make the application PaaS compatible. As a proof of concept, we developed an open source PaaS management application as a regular web application and then deployed it on the cloud.     

云基础设施下的体系结构、挑战与机遇

在工业界和学术界的大力推动下,云计算作为一种新的服务模式,大致可分为将软件作为服务(Software as a service),将平台作为服务(Platform as a service),和将基础设施作为服务(Infrastructure as a Service).现有的绝大部分关于云计算的研究和讨论都集中在前两种服务.本文试图探讨云基础设施的体系结构及其面临的挑战和机遇.从冯.诺伊曼体系结构开始,计算机系统结构的研究基本上就可简单归类于三个问题:计算、存储与传输,三者相互影响.我们认为云基础设施也不例外.本文探讨了云计算的特点和优势,并从云体系结构的角度,探讨了云基础设施下的云计算、云存储和云传输所面临的挑战及其带来的可能的各种技术革命.     

Performance evaluation of cloud computing platforms using statistical methods

Cloud computing is a very attractive research topic. Many studies have examined the infrastructure as a service and software as a service aspects of cloud computing; however, few studies have focused on platform as a service (PaaS). According to recent reports, demand for enterprise PaaS solutions will increase continuously. However, different sectors require different types of PaaS applications and computing resources. Therefore, an evaluation and ranking framework for PaaS solutions according to application needs is required. To address this need, this study presents the most essential aspects of PaaS solutions and provides a framework for evaluating the performance of PaaS providers. It also proposes a suitable set of benchmarking algorithms that can help determine the most appropriate PaaS provider based on different resource needs and application requirements. Performance evaluations of three well-known cloud computing PaaS providers were conducted using the analytic hierarchy process and the logic scoring of preference methods.     

基于Azure的云安全研究

随着云计算的进一步推进和发展,云计算面临的安全问题变得越来越突出,特别是在云计算带来的诸多利益下,如何满足用户在云计算环境下对用户数据的机密性、完整性等相关性能的需求,已成为云计算安全的首要难题。文中以微软Azure平台为基础,从云安全分析人手,针对WindowsAzure云安全进行分析研究。在Azure架构下,探讨Azure云安全解决方案,分别从IaaS、PaaS、SaaS三个角度对微软Azure云平台安全方案给出应对措施,为进一步对微软Azure云平台进行更深层次的测评分析提供技术支持。     

Rafhyc: an Architecture for Constructing Resilient Services on Federated Hybrid Clouds

Federated hybrid clouds is a model of service access and delivery to community cloud infrastructures. This model opens an opportunity window to allow the integration of the enhanced science (eScience) with the Cloud paradigm. The eScience is computationally intensive science that is carried out in highly distributed computing infrastructures. Nowadays, the eScience big issue on Cloud Computing is how to leverage on-demand computing in scientific research. This requires innovation at multiple levels, from architectural design to software platforms. This paper characterizes the requirements of a federated hybrid cloud model of Infrastructure as a Service (IaaS) to provide eScience. Additionally, an architecture is defined for constructing Platform as a Service (PaaS) and Software as a Service (SaaS) in a resilient manner over federated resources. This architecture is named Rafhyc (for Resilient Architecture of Federated HYbrid Clouds). This paper also describes a prototype implementation of the Rafhyc architecture, which integrates an interoperable community middleware, named DIRAC, with federated hybrid clouds. In this way DIRAC is providing SaaS for scientific computing purposes, demonstrating that Rafhyc architecture can bring together eScience and federated hybrid clouds.     

Efficient resource allocation for optimizing objectives of cloud users, IaaS provider and SaaS provider in cloud environment

The cloud architecture is usually composed of several XaaS layers—including Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS). The paper studies efficient resource allocation to optimize objectives of cloud users, IaaS provider and SaaS provider in cloud computing. The paper proposes the composition of different layers in the cloud, such as IaaS and SaaS, and its joint optimization for efficient resource allocation. The efficient resource allocation optimization problem is conducted by subproblems. The proposed cloud resource allocation optimization algorithm is achieved through an iterative algorithm. The experiments are conducted to compare the performance of proposed joint optimization algorithm for efficient resource allocation with other related works.     

国内云计算研究现状与未来

云计算一直是学术界和企业界研究的热点,文章基于三大中文数据库提供的数据,从云计算研究现状以及基础设施即服务(IaaS)、平台即服务(PaaS)、软件即服务(SaaS)三方面研究现状对国内云计算的具体研究状况作出了统计、比较与分析,并对未来的发展做了具体的展望。希望通过一系列的研究与总结,对国内云计算的发展研究起到积极的推动作用。     

云计算安全隐患及其对策分析

从构成云计算的三个主要方面深入分析可能存在的安全隐患,着重对云计算的SaaS、PaaS、IaaS三大服务模式存在风险的可能展开研究分析,同时对加强云计算安全的措施提出了建议。     

企业PaaS平台产品选择框架研究

云计算的三层服务架构（SaaS、PaaS、IaaS）正深刻地影响着企业信息化系统建设,其中平台即服务（PaaS）产品选择问题成为当前企业私有云构建中的棘手问题,至今仍无好的解决方法。为此,提出一个企业PaaS平台产品选择框架,分别从PaaS产品选择的需求分析、测评指标和评选方法三方面研究融合云计算模式的企业面向服务体系架构,PaaS产品评价指标体系的构建方法和基于ANP的多属性产品选择决策过程。通过一个案例展示该选择框架在提高企业PaaS平台产品选择决策水平中的作用。     

MobiCloUP!: a PaaS for cloud services-based mobile applications

The integration of cloud computing and mobile computing has recently resulted in the Mobile Cloud Computing (MCC) paradigm which is defined as the availability of \(c\) loud services over a mobile ecosystem. Platform as a Service (PaaS) is a model of cloud computing that refers to high-level software systems delivered over Internet. This model typically enables developers to deliver Web applications as Software as a Service. With the aim of providing support to the MCC, in this work a PaaS called MobiCloUP! is proposed for mobile Web and native applications based on third-party cloud services such as Netflix, Instagram and Pinterest, to mention but a few. Unlike other commercial solutions such as force.com, Google \(^{\mathrm{TM}}\) App Engine and other academic proposals like MOSAIC, MobiCloUP! implements an automatic code generation programming model targeting rich mobile applications based on both Web standards such as HTML5, CSS3 and AJAX and Rich Internet Application frameworks like Adobe \(^{\textregistered }\) Flex. The MobiCloUP! core is a wizard tool that covers design, publish/deployment, development and maintenance phases for mobile development life-cycle. In order to validate our proposal, Web 2.0 services-based Web and native mobile applications were developed and deployed to the Cloud using MobiCloUP!. Finally, a qualitative-comparative evaluation was performed in order to validate the legitimacy of our proposal against other similar commercial proposals.     

云视频会议平台研究

为解决云计算环境下视频会议的开发与应用,提出了包括基础设施即服务IaaS、平台即服务PaaS和软件即服务SaaS的云视频会议平台框架,分析了云视频会议的服务功能和会议流程,并建立了云视频会议平台系统。平台的应用能够促进信息的实时沟通,在降低企业开发、维护成本的同时,提升企业的决策能力。     

基于SaaS的弹性云平台优化调度策略设计

云计算平台利用虚拟化技术使软件应用变得更有效率的同时, 也给资源管理和服务调度带来了挑战。在研究了软件服务（SaaS）与基础设施服务（IaaS）调度的区别基础上, 重点考虑SaaS层的资源调度, 提出基于随机理论的调度模型, 把该层调度描述成一种多目标的优化问题。除了服务质量的要求, 还考虑了弹性这一云服务的重要特性, 并提供了任务调度与弹性服务副本的匹配策略。实验表明本调度机制的设计优化了云平台的整体性能, 达到了较好的负载均衡与资源利用率。     

基于云计算的工商办公自动化系统的设计与实现

办公自动化系统是为适应现代无纸化及网络化办公的趋势,更好地服务于现代办公操作,基于B/S模式而开发的一套应用于工商系统的办公自动化系统.系统在设计与实现上基于云服务模式,将系统构架分为基础设施层(IaaS)、系统平台层(PaaS)、应用服务层(SaaS).基于云服务平台的设计,能够提升系统的可靠性和数据存储安全性,实现硬件资源共享和动态调整,实现应用弹性部署,为各机关提供个性化定制服务,降低运维成本、实现节能减排,并提升技术的先进性,并奠定业务的可扩展基础.     

云计算架构下的网站群应用实践

云计算正在由概念逐步走进现实,其广泛的应用前景已初现端倪。以政府机构网站群建设为对象,阐述应用云计算支撑政府机构网站群架构的安全性设计和应用方法。从两个方面构建网站群应用环境。一方面,以IaaS的模式搭建支撑网站群应用的云计算基础平台,以SaaS的模式搭建网站群内容管理云计算应用平台;另一方面,运用公有云和私有云环境,保障网站群系统安全和信息安全。更加方便、灵活地满足互联网信息传播需求,为政府运作及企业发展提供更加完善的信息化支撑服务。