【作者】 佟强；

【导师】 贺红；

【作者基本信息】 山东大学 ， 软件工程， 2009， 硕士

【摘要】 Internet及其上应用的快速发展与普及,使计算机软件所面临的环境从静态封闭逐步走向开放、动态和多变。这种变化给传统的软件工程理论、方法、技术和平台研究带来了新的挑战,也导致了基于Internet的新型中间件平台在软件资源管理中的应用。SaaS(Software as a Service)是一种基于Internet计算环境的新型软件资源管理方式,代表了网络软件技术发展的最新趋势。本研究受威海市外贸局委托,设计与建立威海市服务外包公共技术平台原型系统(SaaS_wh)并进行成本分析。本着“软件即服务”的理念,SaaS提供商为企业搭建信息化所需要的所有网络基础设施及软件、硬件运作平台。用户将服务托管在SaaS平台上,只要能上网就能使用SaaS上的资源。用户只需租赁所需的服务、无需维护、按需使用,节省了购买软硬件的成本。SaaS对财力不足的中小型企业无疑是一种发展捷径。在这种背景下,本文调查分析了威海市IT企业的现状和实际需求,设计并实现了一个低成本的威海市服务外包公共技术平台SaaS_wh。首先,我们分析了国内外SaaS发展现状,借鉴苏州等其它城市建设SaaS的经验,结合威海市IT企业的实际需求和城市自身的优势及不足,肯定了建设SaaS平台的可行性和迫切需要,并提出了建设平台要解决的相关技术问题。论文第二部分对整个SaaS_wh系统进行了总体设计,按照SaaS体系结构中关键技术和核心问题对各个模块的设计进行了详细描述。先介绍了门户网站设计的基本架构和平台所能提供给用户的各种服务;其次对用户关注的数据安全问题进行了说明,解决了身份认证和访问控制上的安全问题,并介绍SaaS_wh系统使用的数据存储隔离性的相关技术,显示出该平台良好的数据安全性,接着给出了对技术平台上的海量计算和存储问题的解决方案:采用Google的MapReduce技术和文件下载的分布式技术解决了海量计算并发性问题,采用GFS和HDFS解决大文件的分布式存储,并且采用ADFS解决小文件的分布式存储。该部分通过门户网站引入了中国科学院软件所软件工程中心在国家863支持下完成的TrustIE公共构件库和可信计算环境,通过山大的SaaS_wh平台,TrustIE上的所有资源对威海市免费试用,对资源共享和大学服务地方是个极大的促进。SaaS_wh的另外一个设计重点是引入大连海辉软件公司与山东大学威海分校合作研发的自主软件实训系统,学生或企业研发人员可以随时通过登录SaaS_wh并提交个人信息获得CDK,在自己方便的时候进行自主实训,该系统目前已经通过测试并对校内免费开放。论文第三部分是SaaS_wh实现的技术方案。整个方案采用国产化设计、业界领先的浪潮虚拟化+四路四核服务器,配合后端FC-SAN存储实现。采用HA集群、DRS和VMotion技术提高资源利用率。在ESX服务器上为每个用户建立各自的虚拟机,部署其相应的计算环境,使用户能有效的使用各种资源。方案中使用一台独立的服务器对IT环境提供集中管理、操作自动化、资源优化和高可用性。该服务为数据中心提供了前所未有的响应能力、可维护性、效率和可靠性级别。最后,本文对该SaaS_wh系统的原型的运行情况进行了简要说明,对该平台随着投资增加可以进行的改进提出了方案,并针对威海市投资少、IT企业少的现状探索出一种成本最低的运营方案。综上所述,本文基于SaaS技术的特点和威海市实际需求,设计并实现了威海市公共技术平台SaaS_wh原型系统,该平台技术先进、功能齐全、成本低,能很好地满足威海市服务外包产业发展的需要并且可以随着投资增加继续扩展功能。系统目前仍在继续建设中。更多还原

【Abstract】 The rapid development and widespread of Internet brings us a new challenage to study new theory, methods, technology and platform of software engineering. Software development is going into an open dynamic and changeful invironment based on Internet instead of static and seal. SaaS platform is a new kind of software platform and represents the software technology development trends. The SaaS providers have built all network infrastructure, software and hardware platform which users need. Users only need to lease the required services from the providers and pay for the corresponding services. Users can use SaaS as long as they can login network. Users have a lot of convenience including bought to use, no maintenance and using on demand. So they can save a lot of unnecessary costs, need not to risk purchasing software. Undoubtedly it is a development opportunity for the small and medium-sized enterprises, that is, SaaS has opened a shortcut for them. In this background, this paper researches and analyzes the status quo and actual demand of IT enterprises in Weihai, and finally design and implement Weihai service outsourcing public technology platform.In the first section, the paper bases on discussing the background of SaaS, analyzes the development status quo of SaaS at home and abroad, draws on the experience of other cities in building SaaS and combines with the actual demand of IT enterprises in Weihai and the city’s own strengths and weaknesses. We conclude that it’s feasible and urgent to develop this platform in Weihai. We also propose the problems which to be solved.In the second section, this paper particularly designs the whole platform. We describe the design of each module in detail in this section based on several key problems in SaaS. Firstly, we introduce the basic framework of the gateway website design and various services the platform can provide for users, Secondly, we describe the data security issues user concerned, solve the identity authentication and access control issues, and introduce related technologies of data storage isolation, showing that the platform has good security. Users do not have to worry about their own data will be lost or stolen, eliminating their worries. Thirdly, the amount of calculation of technical platform and storage problems are solved. This paper uses the MapReduce technology of google and Download file distributed computing technology to solve the problem of massive calculation, GFS and HDFS to solve distributed storage for large files and ADFS to solve distributed storage for small file storage. Finally, public component library is described, which is based on the software reuse and improve the Shanghai public component library.In the third section, this paper implements the platform. The scheme adopts industry-leading Inspur virtualization and four-socket, quad-core server with back-end FC-SAN storage. The cluster, DRS and HA VMotion technology are used to improve resource utilization. We build the virtual machine and deploy their corresponding calculation environment in the ESX server for each user. So they can effectively use each kind of resource. There are separate servers which provide centralized management, operation automation and resource optimization and high availability for IT environment. These services provide unprecedented response ability and maintainability, efficiency and reliability level for data centers. At last, these papers describe the advantage of the fiber FC-SAN. Using FC-SAN can obtain more mature, more stable, open and the higher security.Finally, this paper analyzes the application of SaaS platform briefly and put forward some suggestions according to the development trend of SaaS.In summary, this paper based on the SaaS platform features and the actual demand of IT companies in Weihai, design and implement Weihai service outsourcing public technology platform. SaaS_wh is of advanced design, low cost and complete functions which satisfiies the demands of Weihai government. With the increasing investment, SaaS_wh can be improved continuously. The system is still being improved now.更多还原