【作者】 王卓昊；

【导师】 王希诚；

【作者基本信息】 大连理工大学 ， 计算机应用技术， 2012， 博士

【摘要】 信息是人们利用计算机获取的最重要的资源。伴随信息技术的发展,信息资源的共享与利用将获得更高的效率。由于网络环境下信息资源具有数字化性、动态性、无序性、共享性等特点,“信息集成”已成为网络环境下信息科学发展及各学术界关注和研究的重大课题之一。随着网络环境下信息集成范围的不断扩大、集成需求的不断复杂化,由最初面向单一、特定的集成应用需求发展起来的传统信息集成方法逐渐暴露出封闭僵硬、被动应对、低效高价等诸多问题。为此,需要采用一种新的思路来考虑信息集成,即重新思考“如何应对信息集成的规模化、主动化、集约化的发展趋势”针对上述问题,本文提出利用SaaS模式来研究一种新的信息集成方法和技术,以减少信息异构问题、降低信息共享代价、促进信息服务共享、加速信息集成开发,并在研究SaaS模式的信息集成方法和框架基础上,重点关注其中涉及的三个关键问题：(1)如何为信息资源共享提供透明且低成本的数据(特别是关系型数据)存储和管理设施；(2)如何组织管理由不同用户提供的大量信息服务,并保障这些第三方提供的信息服务的可用性；(3)如何从全局的运营和优化角度进行信息资源的规划度量、信息服务治理评估以及信息集成应用运行调度。本文综述了信息集成的研究现状和发展趋势,特别针对开放式信息集成这一背景研究了软件即服务模式下的信息集成方法和关键技术,包括多租户数据服务、信息服务社区模型、信息服务可用性保障机制、SaaS信息集成下的元数据管理机制等,最后给出了SaaS信息集成支撑平台的设计、实现与应用。论文详细阐述了研究过程,主要贡献在于：(1)针对传统信息集成方法存在的“封闭”、“被动”、“低效”等问题,提出了一种SaaS模式下的信息集成方法(SMⅡ方法)和相应的信息集成参考架构,以满足“规模化”、“主动化”及“集约化”的信息集成发展要求。在SMⅡ方法和信息集成参考架构中,提供多租户数据库服务、信息服务管理和信息集成应用构造三个层次的软件服务,支撑信息集成中涉及的信息资源共享、信息服务提供和信息应用开发三个核心环节。相对于现有的信息集成方法,其具有信息集成范围开放、集成用户参与程度高、集成应用开发代价低等优势,特别适于Web2.0发展趋势下信息集成范围的不断扩大、信息集成需求的不断变化的情况。(2)针对SMⅡ方法中的多租户数据库服务问题,提出了一种面向多租户数据服务的虚拟机资源动态分配策略,通过在一个服务器设备集群上为租户配置部署数据库副本的虚拟机,满足其性能需求。同时,建立了该问题的约束规划模型及优化算法,利用排队论计算特定资源配置虚拟机所能提供的数据库服务性能,使用效用函数度量资源分配结果,在性能模型和效用函数基础上,通过两阶段的贪心算法按照一定粒度调整资源配置寻找问题的近似最优解。实验表明,相对于现有基于模拟退火方式和基于最优化方法的两种典型资源分配算法,该算法可以在明显提高数据库服务器设备的资源利用率的同时保持较好的执行效率(3)针对SMⅡ方法中的信息服务管理问题,提出了一种可扩展的服务社区模型,该模型支持服务元建模、业务规范及服务管控策略自定义,可以使能有界化和有序化的服务管理,并针对服务管理边界的动态演化需求设计了该模型下的服务社区派生机制；同时,还重点针对服务管理中服务可用性保障问题,提出了基于事件的服务可用性监控模型并给出了其形式化定义,该模型允许以自定义方式扩展服务监控指标,可以显式或隐式地选择运行时监控机制和反馈机制,从而可以提高以可用性保障为目标的服务监控系统的适应性。通过实际项目中的服务管理实践表明,与基于UDDI、面向语义等典型的服务管理方法相比,服务社区具有灵活性高、扩展性强、支持服务全生命周期管理等特征。此外,还在上述几方面的研究成果基础上给出了SaaS信息集成支撑平台的设计与实现,形成了一套比较完整和系统的SaaS模式信息集成解决方案和支撑软件。同时,部分研究成果已经在全国科技信息服务网项目中得到实际应用,并取得了良好的示范效果。本文工作得到国家科技基础平台项目(No.2005DKA64201)的资助。更多还原

【Abstract】 Information is one of the most substantial resourses obtained by computer. While the modern information technology and Internet technology are booming, people have the great wish to share information resources to the greatest extend and to obtain and utilize them in a more efficient way. Therefore,"Information Integration" has been one of the most important topic that get lots of attention from the academia in the field of information science. However, present information integration methods and technologies that stem from solving specific and single integration needs, fail to accommodate to the complex integration requirement and the expanding integration scope in network environment. So, we have to consider a new way to deal with information integration to adapt to the scalization, initiative and intensification trends of information integration.According to above cognition of information integration, we propose to research a new information integration method in SaaS (Software as a Service) mode and corresponding technologies in this thesis. Three key problems are focused in our research work:(1) How to provide low-cost and transparent storage and management infrastructure for information data, especially the relational data?(2) How to organize and manage large amounts of information services provided by different users and ensure the availability of these information services?(3) How to operate and optimize the plan of information resources, the governance of information services and the schedule of the integration applications?Aiming at above problems, we summarize the stage of art and trend of information integration first in this thesis. And then, based on the analyses of open mode information integration, we propose a SaaS mode information integration method, called SMII, and a set of technology including multi-tenant database services, information service community, flexible monitor for service availability and three-level metadata management. Finally, it is given that the design, implementation and application of a SaaS mode information integration platform.The thesis mainly contributed to the work that:(1) To solve the problems of traditional closed, passive and inefficient methods for information integration, a SaaS mode information integration method (named as SMII) and corresponding information integration reference framework are proposed to adapt to the scalization, initiative and intensification trends of information integration. In SMII method, software services are provided at data level, service level and application level respectively, to support the three core procedures of information resource sharing, information service provision and information application development. According to the real practice and compared to the current typical methods for information integration, SMII method shows the advantage of openness in information integration scope, high extent in end-user participation of information integration and cost-effectiveness in integration application development, and is very suitable for the situation of information integration scopes extending and requirements changing in Web2.0age.(2) Focused on the problem of multi-tenant database service, we put forward a virtual machine based database hosting method under shared-nothing architecture. In this method, database requirement of tenant is satisfied by deploying database replica on the virtual machine. So the problem is how to optimize the resource (such as CPU, memory, etc.) allocation for the virtual machine which hosts database replica of tenant, to save resource cost while meeting the performance requirement of tenant. We model the above constraint programming problem, and solve the problem through a greedy algorithm based on the performance model and utility function. We concentrate on the impact on resource allocation of replica consistency, virtualization overhead and resource tuning granularity. The experiments show that, the algorithm can optimize more resource cost than other two representative resource allocation algorithms, while keeping the high performance in algorithm execution.(3) After realizing the importance of service management growing with the number and types of service hosted and operated in SaaS mode, we propose a service community model and corresponding derivation mechanism of service community, which are generalized from a real practice of SaaS. Especially, in order to assure service availability during service management, we also present an event based model for service monitoring and give its formalized definition. In the model, a service monitoring metamodel is put forward to define various service monitoring models on demand such that the monitored metrics, the monitor implementation and the monitoring process can be flexibly specified. Compared with the classic UDDI-based or semantic-oriented service management methods, service community have the features of flexibility and extendibility, and can enable the whole lifecycle management of services.Furthermore, based on above research results, we design and implement a SaaS mode information integration platform and form a systematic information integration solution and supporting software. The thesis also describes and discusses a real case study of applying the research results in the nationwide service network for sharing science and technology, which evaluates and shows the practicability of our research work. This work was supported by the National R&D Infrastructure and Facility Development Program of China (the grant No.2005DKA64201)更多还原