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.     

公有云中针对服务提供商的用户隐私保护

用户隐私保护一直是影响云计算推广的重要问题。当前,针对云服务提供商的用户隐私保护研究还只局限于少数特定领域,没有一个较为通用的方案。这严重阻碍了用户对云服务提供商及云计算服务模式的信任。为解决这一问题,首先分析了云环境中信息泄露的特点,并根据云计算服务及模型的特点,引出了一个让云服务各层或各模块相互分离、相互制约的用户隐私保护思路。随后沿用该思路,提出了一套基于PaaS层和SaaS层分离的完整隐私保护方案,让PaaS层和SaaS层服务有不同的云服务商分别提供,并让云服务商在提供服务的同时,根据相应规范限制对方泄露用户隐私。最后,对该方案进行了详细的安全性分析论证,并采用一个实际例子说明了该方案在保护用户隐私中的作用。该方案能在一般的云计算架构中实行,可通用于各类SaaS服务中,具有较强的理论和应用价值。     

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。     

State-of-the-art research study for green cloud computing

Although cloud computing has rapidly emerged as a widely accepted computing paradigm, the research on cloud computing is still at an early stage. Cloud computing suffers from different challenging issues related to security, software frameworks, quality of service, standardization, and power consumption. Efficient energy management is one of the most challenging research issues. The core services in cloud computing system are the SaaS (Software as a Service), PaaS (Platform as a Service), and IaaS (Infrastructure as a Service). In this paper, we study state-of-the-art techniques and research related to power saving in the IaaS of a cloud computing system, which consumes a huge part of total energy in a cloud computing system. At the end, some feasible solutions for building green cloud computing are proposed. Our aim is to provide a better understanding of the design challenges of energy management in the IaaS of a cloud computing system.     

基于NGPD的PaaS平台研究与实现*

云计算是一种将计算和存储任务分配到由大量计算机构成的云中的计算模式。云计算提供三种类型的服务：基础设施即服务（IaaS）、平台即服务(PaaS)和软件即服务(SaaS)。虽然PaaS在云系统中起到了关键的作用,但是目前的PaaS平台存在着服务协同性低、资源匮乏、用户界面不友好等问题。本文设计并实现了基于准则调控和策略驱动的自治式服务协同模型（NGPD）的PaaS平台,其利用自治计算元素实现了自治式服务协同,这是尝试解决现有PaaS平台支持提供云平台型服务不足的探索性研究,为云用户提供了更加高效和经济的平台开发环境。     

Towards an autonomic performance management approach for a cloud broker environment using a decomposition–coordination based methodology

Efficient resource allocation of computational resources to services is one of the predominant challenges in a cloud computing environment. Furthermore, the advent of cloud brokerage and federated cloud computing systems increases the complexity of cloud resource management. Cloud brokers are considered third party organizations that work as intermediaries between the service providers and the cloud providers. Cloud brokers rent different types of cloud resources from a number of cloud providers and sublet these resources to the requesting service providers. In this paper, an autonomic performance management approach is introduced that provides dynamic resource allocation capabilities for deploying a set of services over a federated cloud computing infrastructure by considering the availability as well as the demand of the cloud computing resources. A distributed control based approach is used for providing autonomic computing features to the proposed framework via a feedback-based control loop. This distributed control based approach is developed using one of the decomposition–coordination methodologies, named interaction balance, for interactive bidding of cloud computing resources. The primary goals of the proposed approach are to maintain the service level agreements, maximize the profit, and minimize the operating cost for the service providers and the cloud broker. The application of interaction balance methodology and prioritization of profit maximization for the cloud broker and the service providers during resource allocation are novel contributions of the proposed approach.     

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。     

Comparing PaaS offerings in light of SaaS development

Software vendors increasingly aim to apply the Software-as-a-Service (SaaS) delivery model instead of the traditional on-premise model. Platforms-as-a-Service (PaaS), such as Google App Engine and Windows Azure, deliver a computing platform and solution stack as a service, but they also aim to facilitate the development of cloud applications (SaaS). Such PaaS offerings should enable third parties to build and deliver multi-tenant SaaS applications while shielding the complexity of the underpinning middleware and infrastructure. This paper compares, on the basis of a practical case study, three different and representative PaaS platforms with respect to their support for SaaS application development. We have reengineered an on-premise enterprise application into a SaaS application and we have subsequently deployed it in three PaaS-based cloud environments. We have investigated the following qualities of the PaaS platforms from the perspective of SaaS development: portability of the application code base, available support for creating and managing multi-tenant-aware applications, and quality of the tool support.     

基于PaaS平台的定制化教学管理功能开发研究

一款合适的教学管理系统是规范人才培养流程,提高人才培养质量的重要辅助工具。硕士与博士的科研任务繁重且管理流程复杂,不同高校、不同历史时期对学生的培养模式都不相同。所以一款好的教务管理系统应当是定制化的、灵活可调整的,能够适应高校培养模式多样性的特点,并且能够对数据进行复杂的分析处理,可以帮助研究生院更加规范且高质量地管理人才,更好地推进学生工作。故系统的开发架构需要是灵活的、可定制的,底层架构稳定且性能强的。根据以上开发需求选择PaaS平台作为系统的开发平台。PaaS是云计算服务的一种,平台即服务。根据高校研究生院的特点与需求,基于PaaS平台搭建并实施开发了一个定制化的教务管理系统。培养方案与培养计划的制定是高校人才管理的核心内容,也是教务管理系统的主轴。以培养方案、培养计划功能为例,着重介绍系统教学管理部分的设计与开发。     

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。     

云WAF技术系统研究

如今云WAF已经开始正式商业化,它既是Web应用防火墙的云模式,也是一种全新的信息安全产品模式,已经具备了完善的功能定义和成熟的技术平台。云WAF服务提高了云计算的安全性,增强了应用的可用性和安全性,也提升了网络的总体安全性。云WAF正处于高速应用发展阶段,文章结合实际情况,针对云WAF平台的整体架构和具体技术策略进行了分析和探讨。     

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.     

共享式Web应用服务器集群的资源整合方法研究

PaaS(platform as a service)平台是一种重要的云计算服务类型,但传统的Web应用服务器集群管理方式无法为PaaS平台多承租和动态资源管理提供有效支持。针对上述问题,提出了一种基于进程隔离的共享式集群拓扑结构,支持多个Web应用服务器集群共享相同的物理服务器环境。同时给出了针对此共享集群的服务器整合方法,以满足租户应用的性能需求和提高服务器的有效资源使用率。实验证明,平台能够根据当前共享集群的状态选择适当数量的服务器,服务器整合方法有效可行。     

基于区块链的外包服务公平支付方案

随着外包计算服务的快速发展,云计算吸引了越来越多的个人和企业使用外包服务提供商的服务.而雾计算进一步将云计算扩展到网络边缘,在雾计算中,用户由于受计算资源的约束,所以将计算任务外包给雾节点.然而,用户和雾计算节点之间的相互不信任,将会导致公平支付的问题.现有的大多数解决方案采用的是传统的支付机制,需要依赖银行来实现支付.为了实现外包服务的公平支付问题,本文提出了基于区块链的外包服务公平支付方案,通过区块链智能合约支付报酬.同时本文提出的方案可以确保如果雾计算节点完成了计算任务,则用户必须支付报酬给雾计算节点.而如果雾计算节点没有完成计算任务,则用户可以获得赔偿.系统分析表明本方案实现了外包服务的正确性和公平性,并且其消耗在可接受范围内.     

云计算服务质量测评指标体系研究

随着云计算服务的兴起,云计算服务质量的定义、度量和评价的一致性问题逐渐引起各大云计算服务提供商和云计算用户的关注。因此,研究云计算服务质量测评方法和指标体系,通过服务质量评估,为评估云计算服务水平提供数据支撑和决策依据,势在必行。为此,本文针对云计算服务质量的测评方法和评价指标体系缺失等问题,在掌握现有国内外云计算服务质量测评方法、解决方案及其应用情况的基础上,借鉴其成熟的模型和思路,开展云计算服务质量测评指标方法研究。通过搭建云计算服务质量测评指标体系,提炼云计算服务质量评估要求,让云计算服务质量测评真正落地。     

一种基于Docker的开发者服务平台设计

平台即服务(PaaS)作为云计算的三种服务模型之一,为应用程序提供运行环境,并将应用的部署和依赖关系管理起来,极大的方便了应用开发者。Docker基于LXC的轻量虚拟化特点,启动速度快且占用资源少,为PaaS的构建提供了良好的支持。本文分析了Docker的特点,设计了一种基于Docker的开发者服务平台,为开发者提供代码托管、编译发布和运行环境等服务。实验测试结果表明,该设计方案具有系统资源占用少和快速部署的优点。     

SLA-driven dynamic cloud resource management

As the size and complexity of Cloud systems increase, the manual management of these solutions becomes a challenging issue as more personnel, resources and expertise are needed. Service Level Agreement (SLA)-aware autonomic cloud solutions enable managing large scale infrastructure management meanwhile supporting multiple dynamic requirement from users. This paper contributes to these topics by the introduction of Cloudcompaas, a SLA-aware PaaS Cloud platform that manages the complete resource lifecycle. This platform features an extension of the SLA specification WS-Agreement, tailored to the specific needs of Cloud Computing. In particular, Cloudcompaas enables Cloud providers with a generic SLA model to deal with higher-level metrics, closer to end-user perception, and with flexible composition of the requirements of multiple actors in the computational scene. Moreover, Cloudcompaas provides a framework for general Cloud computing applications that could be dynamically adapted to correct the QoS violations by using the elasticity features of Cloud infrastructures. The effectiveness of this solution is demonstrated in this paper through a simulation that considers several realistic workload profiles, where Cloudcompaas achieves minimum cost and maximum efficiency, under highly heterogeneous utilization patterns.     

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.     

POP:一个基于微服务架构的在线编程系统

随着云计算的发展,基于云端的编程模式越来越受到开发者的青睐。在线编程系统与PaaS平台相结合,可以大大简化应用开发过程,为开发者提供便利。Docker的出现推动了PaaS平台的迅猛发展,Docker的种种特性给予了在线IDE更加理想的开发部署应用的环境。POP(Public Online Programming) 是一种利用Docker技术实现的基于微服务架构的公共在线编程系统。POP通过对Docker资源的合理调度管理,使得在线编程系统在部署、调试和运行各类应用时能够更加节省资源和时间。