一种面向多租户中间件的应用级并发控制方法

针对在多租户中间件上存在的租户隔离、资源侵占的问题,提出一种面向多租户中间件的应用级并发控制方法。首先分析了现有并发控制方法的局限性,然后介绍了一种基于工作管理器的多租户请求处理模型的原理及设计,进一步给出了基于该模型的应用级并发控制方法的设计与实现,最后通过实验测试方法的性能开销,并设计了一个多租户性能隔离方法来验证方法的应用效果。实验结果验证了方法的有效性。     

面向SaaS应用的SMTDM可伸缩多租户数据管理框架

云计算是一种可以弹性并按需提供资源的技术.在多租户共享数据存储模式下,如何实现数据的动态伸缩存储是云数据管理的关键.针对SaaS应用如何随着租户数量及请求规模的变化而进行自适应伸缩的问题,在分析数据存储层的伸缩性需求的基础上,基于Walraven等人提出的多租户架构思想,扩展典型的云应用架构,设计了一个多租户数据管理框架,实现存储资源的弹性.基于该框架,开发了一个面向网络管理领域的SaaS原型系统,验证了其有效性和可用性.     

面向服务的多租户访问控制模型研究

传统访问控制模型在多租户环境下无法满足租户之间的隔离访问以及对各租户的访问请求实行有效的统一管理的需求。为了在多租户环境下实现一套快速的、访问控制可配置的实施方案, 提出了一个面向服务的多租户访问控制模型。根据对多视图业务模型之间的关联进行分析, 识别出组织模型及其相关的资源模型。通过映射和转换将组织模型转换为面向服务的多租户访问控制模型, 并构建访问控制模块以配置和运行访问控制模型。最后以某交通物流信息平台为范例验证了该模型的可行性和有效性。验证结果表明, 模型能够在多租户环境下提供兼备快速配置与访问控制的实现支持。     

面向多租户的属性标签分层方案

Saa S模式中租户与服务商之间一直存在信任问题,将服务商与租户分开管理,借助标签跨域访问则存在效率瓶颈和标签安全的问题。利用属性特征结合标签,设计出一个针对多租户跨域访问的方法,将标签根据属性分类管理,再把跨域访问的权限赋予各属性标签,实现平台内通过属性标签的跨域访问。最后,通过实验和分析验证了该属性标签保护方法的高效性。     

面向多租户数据存储的分段多维性能模型

多租户数据存储对提高用户体验质量,优化系统运行效率,降低服务提供商成本至关重要。面对大规模租户,共享数据存储节点如何满足不同租户的不同性能需求是需要解决的关键问题。为此,针对多租户数据存储不同性能需求的特点,提出了一种面向多租户数据存储的考虑租户之间相互干扰的分段多维性能模型,包括分段多维性能边界函数和多租户数据存储性能预测分析方法。通过基准测试数据采集、模型计算和性能分析,来判断是否每个数据存储节点能够综合地满足不同租户的不同性能需求。实验系统的分析结果表明,该方法能够判断在特定租户负载组合下每个数据节点是否过载,为分布式多租户数据布局提供基础。     

多租户高可用并行任务调度框架

描述了一种多租户高可用并行任务调度框架MTHPT的设计思想、体系结构和实现技术,MTHPT包括3部分：任务定义与配置、异步并行任务调度模式、消息告警与监视.任务调度引擎和任务执行组件采用分开部署、异步并行调度和快速回调的模式,快速释放调度引擎占用的线程资源,解决了部分任务执行周期长、定时任务无法按时执行等影响业务系统性能的问题.任务调度配置提供了多租户应用模式.实验分析及评估表明,MTHPT提高了应用系统的任务调度并行调度效率和稳定性.     

面向多租户应用CPU资源消耗的回归分析方法改进研究

回归分析作为一种估算资源消耗的方法常用于克服不易于直接测量的问题,但在多租户应用的动态负载环境下效果并不好。针对多租户环境下的动态负载变化,以CPU资源消耗为研究目标,提出一种基于回归分析方法的改良策略,减少共线性影响从而提高评估的精确度。实验结果表明,在动态的负载环境,所提方法能较好的适应多租户环境,平均估算误差得到改善。     

多租户网站实现方法的研究和设计

传统网站的建设都是各自为政,存在重复建设和维护管理成本过高等问题。本文应用SaaS多租户、J2EE、元数据管理等技术,给出多租户网站框架以及关键实现技术,能较好地解决多租户网站设计和满足个性化需求等问题。     

基于可信计算的多租户隐私数据保护

针对多租户应用的隐私数据保护问题, 在分析多租户应用的特点和隐私数据保护需求的基础上, 将可信计算技术引入多租户隐私数据保护, 基于虚拟可信平台模块vTPM提出了一种具有定制性的加密保护方案, 利用vTPM提供的加密密钥对租户的隐私数据进行加密, 同时利用vTPM的密钥保护和管理功能对加密密钥进行保护. 最后, 基于Xen实现的vTPM实现了本方案.     

支持混合负载的网格资源管理框架

多年来,网格资源管理技术的研究只是关注单一应用负载的性能提高,忽略了资源的可扩展服务能力,制约了网格系统从科学计算领域向更广应用领域的推广。针对以上问题提出了一种支持混合负载的网格资源管理框架,所提的策略约束资源分配方法通过将多种“负载—资源”的共享关系抽象成消费者共享策略树,使资源的获取能够同时满足批处理、SOA服务等多种类型混合负载的性能要求,从而大大提高了系统整体的用户效益。     

A relational framework for join implementation in model management systems

Two important issues in the design of relational model banks are the degree to which they should be aggregated or disaggregated and the methods by which disaggregated model banks might be integrated in response to user queries. Three topics relevant to this issue are addressed in this paper. The first is whether a universal model and its projections may possess the lossy join property. We will show that they do not. The second is the development of a relational algebra for the specification of join implementation in model banks, and the third is the realization of such an algebra in a language similar to Query-by-Example.     

Developing a framework for sustainability management in engineering SMEs

Sustainability issues in manufacturing and production are growing exponentially. Initially referring to environmental considerations, sustainability now also encompasses social, ethical and economical responsibilities. This paper focuses on engineering and manufacturing SMEs and outlines a regional study undertaken on a small number of these companies which have succeeded in developing appropriate tools and strategies to satisfy the current ISO 14001 standard. Their experiences, strategies and solutions are used to devise and develop a framework for sustainability management, taking an incremental approach in moving from environmental management, using ISO 14001 as a foundation, to sustainability management which will contribute to an annual sustainability report which is currently only undertaken by large corporations. The framework consists of two levels, with the first focusing on ISO 14001 and the second aimed towards managing all social, environmental and economical aspects within an engineering SME. Key results from the regional study of ISO 14001 certified engineering SMEs highlight the importance of environmental and sustainability awareness programs for top management, eliciting and obtaining their full support and commitment.     

A framework for modelling multiple resource management issues—an open modelling approach

Our experience with development and distribution of environmental decision support systems (EDSSs) for delivering research outcomes to catchment managers has identified major impediments to their adoption. These include protracted development time, focus on single impacts, difficulty in combining results with other EDSSs, and no attention to socio-economic factors. Based on the premise that decision support tools can play a major role in the integration and adoption of research outcomes, we are developing a software tool for rapid building of EDSSs which can handle multiple issues across different scales. The prototype is called the Open Modelling Engine (OME). This paper describes the background to the development of the OME, its basic architecture, an OME-built EDSS for catchment nutrient management, and concludes with a discussion on research direction and opportunity.     

基于资源空间模型的虚拟场景技术研究

本文在分析了资源空间模型和文件管理系统理论的基础上,提出了一种基于资源空间模型的虚拟场景绘制系统,详细说明了该系统的工作原理和具体流程并论述了其应用与前景。最终结果表明,该系统直观,便于对个人计算机中数量巨大类型各异的文件进行管理,而且便于高效查看和操作任何维度的资源。是一种实用的虚拟场景绘制系统。     

Modeling a resource contention in the management of virtual organizations

A virtual organization provides a cost-efficient method allowing different autonomous entities, such as organizations, departments and individuals, to extend service offerings in a virtual marketplace. To support cost-efficient service provisioning, a suitable procedure must be applied to determine the amount of resources necessary for the operation of virtual organizations.We propose a new mathematical model for a quantitative performance evaluation of resource management in virtual organizations. We present an efficient algorithm to determine the steady state probabilities and the performance measures of the system. A comparison with a detailed simulation model and other numerical approaches shows that the proposed algorithm is fast and accurate. This algorithm can therefore be used for resource dimensioning to support the cost-efficient operation of virtual organizations.     

Predictive resource management for meta-applications

This paper defines meta-applications as large, related collections of computational tasks, designed to achieve a specific overall result, running on a (possibly geographically) distributed, non-dedicated meta-computing platform. To carry out such applications in an industrial context, one requires resource management and job scheduling facilities (including capacity planning), to ensure that the application is feasible using the available resources, that each component job will be sent to an appropriate resource, and that everything will finish before the computing resources are needed for other purposes.

This requirement has been addressed by the PAC in three major European collaborative projects: PROMENVIR, TOOLSHED and HPC-VAO, leading to the creation of job scheduling software, in which scheduling is brought together with performance modelling of applications and systems, to provide meta-applications management facilities. This software is described, focusing on the performance modelling approach which was needed to support it.

Early results from this approach are discussed, raising some new issues in performance modelling and software deployment for meta-applications. An indication is given about ongoing work at the PAC designed to overcome current limitations and address these outstanding issues.     

UML人力资源信息管理系统建模的研究

以建立人力资源信息管理系统为目的,研究和探讨了利用统一建模语言UML(Unified Modeling Language)对系统进行建模和开发的过程。