基于运行时模型的多样化云资源管理方法

多样化的受管资源和不断变化的管理需求,使得云管理面临很大的难度和复杂度.面对一个新的特定的管理需求,管理员往往是在已有管理软件的基础上进行二次开发,通过管理功能的获取和组织来构造新的管理系统.然而,由于缺乏通用的方法,二次开发的难度和复杂度依然很大.为了能够根据管理需求快速定制、集成、扩展已有的管理软件,提出一种基于运行时模型的多样化云资源管理方法.首先,在系统管理接口的基础上构造不同受管资源的运行时模型;其次,通过对不同的运行时模型进行合并,来构造包含所有目标受管资源的组合模型;最后,通过组合模型到用户特定模型的转换,来满足特定的管理需求.在OpenStack与Hyperic两款独立管理软件的基础上,实现了基于运行时模型的虚拟机软、硬件资源统一管理系统,验证了方法的可行性和有效性.     

基于运行时模型的混合云管理方法

随着云计算技术的普及,涌现出众多不同用途、不同类型的云计算平台.为了满足遗产系统整合和动态资源扩展等需求,常常需要构造混合云来统一管理不同云平台中的计算和存储资源.然而,不同云平台的管理接口和管理机制存在差异,使得开发混合云管理系统难度大、复杂度高.本文提出一种基于运行时模型的混合云管理方法：首先,在云平台管理接口基础上,构造单一云平台的运行时模型;其次,根据云平台领域知识,提出一种云平台软件体系结构的统一模型;最后,通过模型转换,实现云平台统一模型到运行时模型的映射.于是,管理程序可以建立在云平台统一模型的基础上,降低了混合云管理系统开发的难度和复杂度.本文还实现了基于运行时模型的CloudStack和亚马逊EC2混合云管理系统,并对方法的可行性和有效性进行了验证.     

基于EJB分布式应用的动态配置

分布式应用程序在配置时需要引入传输和同步到应用程序代码的高级特性,EJB与CCM组件模型允许程序员声明其服务必须添加到组件的配置描述。然而,这种方法不允许将新服务动态地添加到整体组件。文中提出一种方法允许应用程序在运行时将新服务添加到整体组件。当一个新服务添加到一个组件时,已经运行并存在的服务组件通过平台进行动态地管理。     

基于双层规划的容器云资源动态配置算法

本文分析容器云资源动态配置决策问题,通过定义容器云资源的调度任务,求解得到容器云资源调度时间;利用容器云资源调度任务的最短时间矩阵,获取容器云资源调度所需的条件。在双层规划条件下,求解容器云资源调度的目标函数和约束函数;考虑到用户的任务情况和云数据中心的云资源状况,在虚拟机上构建一个到物理主机的矩阵,通过构建容器云资源动态配置结果在优化时的目标函数,结合约束条件,实现容器云资源的动态配置。实验结果表明,资源动态配置算法不仅可以提高容器云资源的利用率,还可以减少配置完成时间,具有更好的动态配置性能。     

面向云数据中心的人工智能模型自动优化框架设计

人工智能模型的自动调优技术能够以较低资源成本提供云数据中心的高性能智能服务。然而,人工智能模型和硬件设备具有异构性,云数据中心执行自动调优操作会产生大量计算时间,占用算力资源,产生能耗成本。针对此问题,本文设计面向云计算数据中心的人工智能模型自动优化框架。提出人工智能模型候选配置项过滤方法,利用模型构建、特征提取、候选项探索、配置查询等技术对候选项搜索空间重新采样,将高效候选项替换低效候选项。在算子优化层面,框架分批并行执行计算组件实现的硬件测量,避免连续探测搜索空间。在模型优化层面,根据多人工智能模型的相对性能加速优先跨集群的计算组件优化。该框架旨在面向不同人工智能模型,降低人工智能模型推理延迟,减少云计算数据中心能耗,从而提升人工智能模型自动调优的成本效益。     

一种基于性能模型的中间件自配置框架

高动态的计算环境使得QoS(quality of service)保障对于基于组件的分布式系统越来越重要,软件系统需要具备自我调整的能力以适应外部环境的变化.给出一种自适应的中间件配置框架,能够动态感知负载变化,并自动调整系统参数配置以保持用户所要求的服务质量.该框架的核心是一个基于分层排队网络的性能预测模型,用于指导搜索最优的资源配置,使性能需求得到最大的满足.在OnceAS应用服务器上进行原型实现,并以StockOnline应用做实验,比较了在使用和不使用该框架时的性能需求的满足情况.结果显示,在负载增加时,通过自配置框架的调控,应用性能需求的保障程度得到了较大的提升.     

云制造环境下基于双层规划的资源优化配置模型

为了解决云制造环境下制造资源的优化配置问题,综合考虑需求与服务双方以及云平台运营方的利益,提出了一种基于双层规划的资源优化配置模型。该模型以前景理论结合多约束多属性评价体系求解出的供需双方满意度作为上层规划的优化目标;以云平台资源利用率最大化为下层规划的优化目标;通过双层规划并采用改进的i-NSGA-II-JG算法对多目标制造资源配置问题进行求解。最后,通过算例仿真实验证明了该模型的可行性和优越性。     

云环境下基于LQNM的数据库系统自配置框架研究

针对云计算环境下高动态变化的数据库系统负载无法保障服务质量QoS(Quality of Service)的问题,提出一种自适应的数据库系统配置框架。该框架能够根据负载的动态变化,自动调整系统资源配置,从而保障用户要求的服务质量。框架的核心是基于分层排队网络模型LQNM(Layered Queue Network Model)的性能预测模型,用于指导搜索最优的资源配置,满足用户的性能需求。采用Hadoop搭建云计算环境,以TPC-H基准数据进行实验,实验结果显示,通过自适应配置框架对系统资源的调控,系统的QoS得到了很大提升。     

基于均匀分布的高斯云模型

云模型实现了定性概念与其定量表示之间的不确定转换。高斯分布与高斯隶属度函数的普适性奠定了高斯云模型的普适性,目前云模型的理论与应用研究主要集中在高斯云模型。将均匀分布引入到云模型中,扩展了高斯云模型,分别得到了均匀分布云模型和均匀高斯云模型,两类扩展的云模型为不确定性的形式化描述提供了新的途径。最后利用多维均匀高斯云模型模拟分形树生长过程,实验结果表明云模型能有效模拟自然界中不确定的分形现象。     

软件运行时配置研究综述

运行时配置为用户使用软件提供了灵活性和可定制性,但其巨大的规模和复杂的机制也带来了巨大的挑战.大量学者和研究机构针对软件运行时配置展开了研究,以提升软件系统在复杂外部环境中的可用性和适应性.建立运行时配置研究分析框架,从配置分析与理解、配置缺陷检测与故障诊断、配置应用 3 个阶段对现有研究工作进行归类和分析,总结归纳现有研究的不足和面临的挑战,并对未来的研究趋势进行展望,对下一步研究具有一定的指导意义.     

Model-based monitoring and policy enforcement of services

Runtime monitoring is necessary for continuous quality assurance of Web Services. Sensors are critical in runtime monitoring to capture the data and detect anomalies. However, sensors in current monitoring systems are usually manually instrumented or hard-coded in the program. It is expensive to implement, and inflexible to change at runtime. The paper extends our previous research on collaborative monitoring and proposes a model-based approach for automatic generating sensors and enforcing policies. Web Services standards WSDL and OWL-S are taken as the models of service interface, workflow, and semantic. Sensors are generated based on the models from two perspectives: (1) dependency analysis of the data, operations, and services with respect to the ontology model of domain concepts and usage context; (2) coverage strategies to decide the specific logic and paths to cover and the data to capture by the monitoring sensors. Policies are defined as a 3-tuple of type, subject and assertion sets and are specified using WS-Policy standards. They are associated to the sensors and enforced at runtime by the policy engine that interoperates with service execution engine to communicate runtime behavior information and verification results. Prototype system is implemented based on the Eclipse platform where sensors are implemented as the listeners to the process execution and instrumented into the middleware including the OWL-S execution engine and SOAP engine. Experiments show that the monitoring results in low overhead of the system performance, reduced effort and enhanced flexibility of sensor instrumentation.     

VyrdMC: Driving Runtime Refinement Checking with Model Checkers

This paper presents VyrdMC, a runtime verification tool we are building for concurrent software components. The correctness criterion checked by VyrdMC is refinement: Each execution of the implementation must be consistent with an atomic execution of the specification. VyrdMC combines testing, model checking, and Vyrd, the runtime refinement checker we developed earlier. A test harness first drives the component to a non-trivial state which serves as the starting state for a number of simple, very small multi-threaded test cases. An execution-based model checker explores for each test case all distinct thread interleavings while Vyrd monitors executions for refinement violations. This combined approach has the advantage of improving the coverage of runtime refinement checking at modest additional computational cost, since model checkers are only used to explore thread interleavings of a small, fixed test program. The visibility and detailed checking offered by using refinement as the correctness criterion differentiate our approach from simply being a restricted application of model checking. An important side benefit is the reduction in program instrumentation made possible if VyrdMC is built using a model checker with its own virtual machine, such as Java PathFinder [Guillaume Brat, Klaus Havelund, Seung-Joon Park, and Willem Visser. Model Checking Programs. In IEEE International Conference on Automated Software Engineering (ASE), September 2000]. We are investigating the use of two different model checkers for building VyrdMC: Java PathFinder, an explicit-state model checker and Verisoft, a “stateless” model checker [P. Godefroid. Model Checking for Programming Languages using VeriSoft. In Proceedings of the 24th ACM Symposium on Principles of Programming Languages, pages 174–186, Paris, January 1997].     

A framework for computer-aided validation

This paper presents a framework for augmenting independent validation and verification (IV&V) of software systems with computer-based IV&V techniques. The framework allows an IV&V team to capture its own understanding of the application as well as the expected behavior of any proposed system for solving the underlying problem by using an executable system reference model, which uses formal assertions to specify mission- and safety-critical behaviors. The framework uses execution-based model checking to validate the correctness of the assertions and to verify the correctness and adequacy of the system under test.     

Model-based Runtime Verification Framework for Self-optimizing Systems

This paper describes a novel on-line model checking approach offered as service of a real-time operating system (RTOS). The verification system is intended especially for self-optimizing component-based real-time systems where self-optimization is performed by dynamically exchanging components. The verification is performed at the level of (RT-UML) models. The properties to be checked are expressed by RT-OCL terms where the underlying temporal logic is restricted to either time-annotated ACTL or LTL formulae. The on-line model checking runs interleaved with the execution of the component to be checked in a pipelined manner. The technique applied is based on on-the-fly model checking. More specifically for ACTL formulae this means on-the-fly solution of the NHORNSAT problem while in the case of LTL the emptiness checking method is applied.     

面向服务的网络化仿真及运行支撑平台研究

针对分布式仿真技术的发展,结合军事领域内仿真系统构建和运行的军事需求,以面向服务技术为基础,提出了面向服务的网络化仿真构建和运行模式,以满足未来军事系统中仿真的新需求.介绍了网络化仿真的概念及特征,详细分析了网络化仿真运行支撑平台以及相关核心服务,重点研究了运行支撑平台体系结构以及网络化仿真应用服务的构建与运行.最后给...     

运行时验证技术的研究进展

运行时验证是一种轻量级的验证方法,通过实时地监测系统的行为,验证系统的正确性,及时发现冲突,并发出警告或作出反应。运行时验证技术已经得到了越来越多的应用,以确保软件系统的正确性。总结了近年来运行时验证技术的研究进展,首先介绍了运行时验证的概念、原理和分类,接着深入分析了现有的几种解决方案,并对该领域中的研究热点进行了深入探讨,最后分析了运行时验证技术面临的主要挑战,并对未来该领域的研究方向进行了展望。     

基于CAR构件技术回调函数线程模型的研究

CAR构件技术作为一种新型的、功能强大的构件技术,针对其特点,在CAR构件回调机制的基础上提出了基于CAR构件技术回调函数的线程模型,从而提高应用程序的模块化程度,加速应用程序的开发过程.     

基于Matlab Runtime Server的应用与开发

针对目前Matlab与其他高级语言混合编程研究成果中存在的局限性,讨论和研究了基于MatlabRuntimeSever的混合编程技术及其开发流程,并将这一研究成功应用于某型飞机试飞地面数据处理系统的设计与开发中。     

A simple distributed mechanism for accounting system self-configuration in next-generation charging and billing

Modern communication systems are becoming increasingly dynamic and complex. In this article a novel mechanism for next generation charging and billing is presented that enables self-configurability for accounting systems consisting of heterogeneous components. The mechanism is required to be simple, effective, efficient, scalable and fault-tolerant. Based on simulation results it is shown that the proposed simple distributed mechanism is competitive with usual cost-based or random mechanisms under realistic assumptions and up to non-extreme workload situations as well as fulfilling the posed requirements.     

Research on the effects of cloud-based pedagogy for creative talents: A case study on Chinese High School

Training of creative talents during K-12 education affects the future of a nation. As a result, researchers in China and other countries give special attention to the field of pedagogy. This paper evaluated an experimental class of Beijing F High School as the case study, and performed an empirical study on cloud-based pedagogy for training the creative talents, a quantitative study based on the 6 basic aspects of Tyler’s theory, a qualitative study using ethnography for classroom observation that included interviews of teachers, students, and observers, and employed a sequential mixed research method used for data collection and analysis. Results demonstrated that cloud-based pedagogy in the creative-talent class of Beijing F High School focused on objectives in its orientation, the curriculum content, implementation and development reflecting the richness, regression, correlation, and rigor of postmodern curriculum. By using the accelerated and enriched cloud-based curriculum and focusing on the Talent Search Model, the Beijing F High School was able to gain rich experiences in the training of creative talents in Chinese K-12 education.