CFD网格平台中任务管理与错误恢复的实现

任务管理和错误恢复是CFD网格应用平台的核心部分,它对运行在平台上的CFD程序进行管理,并提供错误恢复机制。为了更好地管理CFD任务,平台通过建立CFD程序抽象模型,对任务管理和错误恢复模块进行设计上的优化。因此该模块采用了双层架构,上层实现了对服务的管理,下层负责对并行程序的管理。同时该模块还提供了守护进程CFD-Daemon来实现错误恢复,以及应用开发包供CFD程序员使用。     

CFD验证与确认数据库平台数据结构设计与应用

计算流体动力学（CFD,computational fluid dynamics）验证与确认数据库平台用于存储和管理精细风洞试验、飞行试验、数值计算产生的标准算例数据。针对结构复杂、维度较高且参数不固定的CFD验证与确认标准算例数据,设计一种灵活的数据结构,动态存储不同标准算例的来流状态数据与结果数据,减少数据冗余,提高数据可扩展性。基于该数据结构完成标准算例数据质检与元数据管理设计,确保数据库平台能够精准、高效的为CFD软件可信度评价或相关研究提供数据服务。应用证明,验证与确认数据库平台实现了标准算例数据的有效管理和高效应用,为国家数值风洞工程和国内相关CFD软件的验证和确认提供了有力支撑。     

多平台防空体系中的协同机制研究

多平台怎么进行协同,是多平台防空体系建设过程中面临的最为关键的问题之一。在介绍协同机制在多平台防空体系中的重要作用的基础上,归纳和描述了多平台防空体系中的各种不同的协同机制,并分析和比较了各种协同机制的性能和应用场合。最后,结合作战模式不同的发展阶段,讨论了基于目标分配的3种不同的协同机制。     

基于机群架构的并行数据库中间件系统改进研究

基于机群架构的高性能计算机已经被应用到很多领域,如大气预测、油藏模拟、CFD仿真模拟和Web服务等.随着数据量的爆炸式增长,传统的集中式的数据库系统已经难以满足各种应用的需求,基于机群式架构的并行数据库系统为增强海量数据的存储以及处理能力提供了一种途径.对以前实现的一个基于机群架构的并行数据库中间件系统ParaMidSQL进行了改进.通过对并行选择、并行排序、并行连接等关键操作的测试,给出对并行数据库中间件系统改进后的性能分析.     

基于LinuX系统的容双故障软磁盘阵列平台Deraid

提出并设计实现了一个基于Linux系统平台的容双故障的通用软磁盘阵列平台Deraid。它容许阵列中任意两个磁盘同时出错而保证数据不丢失,可以为各种需要大容量存储的系统提供容量大、吞吐量高的存储服务,同时具有良好的可扩展性,可为各种数据布局提供一个使用方便的实验平台。章讨论了Deraid的总体设计和实现的技术要点,并给出了具体的应用和性能测试结果。     

一类Stencil应用在众核NUMA架构的性能研究

【应用背景】模板计算是CFD（计算流体动力学,Computational Fluid Dynamics）等科学计算的典型算法,其访存性能受到关注。NUMA架构因扩展性好,在以鲲鹏920处理器为代表的ARM架构上普遍被应用。【方法】使用性能分析工具和benchmark程序,对鲲鹏平台的访存和通信子系统进行性能测试。针对典型stencil应用软件CCFD V3.0开展热点分析和性能测试,并建立Roofline模型。【结果】鲲鹏920处理器依托其众核NUMA架构,单节点浮点性能、内存带宽峰值,以及通信时延均优于Intel Xeon E5-2680v2与一款国产处理器。单节点时,CCFD V3.0在鲲鹏平台的运行速度约是Intel平台的2～3倍,是国产处理器的1.5～2倍。【结论】基于ARM架构的鲲鹏平台应用移植简单,其NUMA架构对模板计算一类访存密集性应用具有优势。     

交替方向隐式CFD解法器的GPU并行计算及其优化

交替方向隐格式(ADI)是常见的偏微分方程离散格式之一,目前对ADI格式在计算流体力学（CFD）实际应用中的GPU并行工作开展较少。从一个有限体积CFD应用出发,通过分析ADI解法器的特点和计算流程,基于统一计算架构(CUDA)编程模型设计了基于网格点与网格线的两类细粒度GPU并行算法,讨论了若干性能优化方法。在天河-1A系统上,采用128×128×128网格规模的单区结构网格算例,无粘项、粘性项及ADI迭代计算的GPU并行性能相对于单CPU核,分别取得了100.1、40.1和10.3倍的加速比,整体ADI CFD解法器的GPU并行加速比为17.3     

IDP 平台中轻量级业务框架

IDP（Integrated Data Platform,综合数据业务平台）是开放的、模块化的、基于标准的基础平台,为移动运营商提供了连接底层各种基础服务以及连接上层各种业务的通用平台。基于JBoss的IDP2.0系统在应用过程中,遇到了占用资源多,性能差,维护成本高等问题。为了解决上述问题,介绍了一种IDP轻量级业务框架的总体设计方案,并重点介绍了业务逻辑模块DSP（Data-service Script Processor,数据业务脚本处理器）的设计。该框架具有高性能,易于维护,便于快速开发业务逻辑等优点。     

面向云计算环境的CFD数据可视化分析服务

针对目前CFD(Computational Fluid Dynamics)软件数据可视化分析所需计算量大且操作不灵活的问题，面向CFD数据可视化分析需求，实现了一个CFD数据可视化分析服务原型软件。在该原型软件中，研究了自适应客户端的服务自适应QoS(Quality of Service)优化技术，降低不同客户端计算环境对服务质量的影响；研究设计了基于消息中间件的服务集成接口，提高了服务使用的灵活性。面向云计算环境的CFD数据可视化分析服务发挥了云端服务器的性能优势，应用了“云+端”的开发新模式，具备灵活性和可扩展性。     

无线传感器网MAC协议能耗控制性能研究

为研究无线传感器网对能耗的要求,提出一种无线传感器网媒体接入控制协议,对应用场景进行抽象,基于OPNET构建无线传感器网仿真平台,测试不同应用场景下各种媒体接入控制协议的能耗和延时性能,实验结果表明,任何一类媒体接入控制协议均能在不同应用场景中提供较好的性能,但不是最优的。     

Formal verification technique for grid service chain model and its application

Ensuring the correctness and reliability of large-scale resource sharing and complex job processing is an important task for grid applications. From a formal method perspective, a grid service chain model based on state Pi calculus is pro- posed in this work as the theoretical foundation for the service composition and collaboration in grid. Following the idea of the Web Service Resource Framework (WSRF), state Pi calculus enables the life-cycle management of system states by associating the actions in the original Pi calculus with system states. Moreover, model checking technique is exploited for the design-time and run-time logical verification of grid service chain models. A grid application scenario of the dynamic analysis of material deformation structure is also provided to show the effective- ness of the proposed work.     

基于网格计算的QoS模型的研究

随着网格技术和应用的不断深入，对网格提出了严格的服务质量（quality of service，简称QoS）要求，网格计算中的QoS成为研究应用的焦点．缺乏QoS保证逐渐成为制约网格应用的瓶颈之一。论文对网格计算的质量服务进行了研究，描述了网格QoS定义，网格QoS需求和网格QoS的层次模型。同时也介绍了当前研究思路度以后的发展趋势。     

支持多应用的桌面网格关键技术研究

针对基于多应用的计算需求及桌面网格设计中的主要技术问题,设计了桌面网格架构六层模型,并介绍了关键技术以及具体的实现方法,目的是解决在设计桌面网格架构时所面临的应用部署慢、整合异构计算资源难、作业调度模型少及扩展性差等问题,具体的实现方法包括采用多种通信模块,能够整合不同的计算资源访问系统;通过使用代理作业模块实现作业实例的转换的方法;采用文件系统及镜像服务,实现面向不同应用的作业环境及镜像需求;基于虚拟化技术实现异构计算资源的整合;针对不同应用类型的差异性,开发了通用控制程序组件;面向不同应用类型需求,实现的多种调度模型。基于这些方法实现了支持多应用的桌面网格系统,分析测试结果表明,这些方法可行并具备通用性。     

Semantic-enabled CARE Resource Broker (SeCRB) for managing grid and cloud environment

Grid computing is mainly helpful for executing high-performance computing applications. However, conventional grid resources sometimes fail to offer a dynamic application execution environment and this increases the rate at which the job requests of users are rejected. Integrating emerging virtualization technologies in grid and cloud computing facilitates the provision of dynamic virtual resources in the required execution environment. Resource brokers play a significant role in managing grid and cloud resources as well as identifying potential resources that satisfy users’ application requests. This research paper proposes a semantic-enabled CARE Resource Broker (SeCRB) that provides a common framework to describe grid and cloud resources, and to discover them in an intelligent manner by considering software, hardware and quality of service (QoS) requirements. The proposed semantic resource discovery mechanism classifies the resources into three categories viz., exact, high-similarity subsume and high-similarity plug-in regions. To achieve the necessary user QoS requirements, we have included a service level agreement (SLA) negotiation mechanism that pairs users’ QoS requirements with matching resources to guarantee the execution of applications, and to achieve the desired QoS of users. Finally, we have implemented the QoS-based resource scheduling mechanism that selects the resources from the SLA negotiation accepted list in an optimal manner. The proposed work is simulated and evaluated by submitting real-world bio-informatics and image processing application for various test cases. The result of the experiment shows that for jobs submitted to the resource broker, job rejection rate is reduced while job success and scheduling rates are increased, thus making the resource management system more efficient.     

ParTransgrid: A scalable parallel preprocessing tool for unstructured-grid cell-centered computational fluid dynamics applications

The development of a basic scalable preprocessing tool is the key routine to accelerate the entire computational fluid dynamics (CFD) workflow toward the exascale computing era. In this work, a parallel preprocessing tool, called ParTransgrid, is developed to translate the general grid format like CFD General Notation System into an efficient distributed mesh data format for large-scale parallel computing. Through ParTransgrid, a flexible face-based parallel unstructured mesh data structure designed in Hierarchical Data Format can be obtained to support various cell-centered unstructured CFD solvers. The whole parallel preprocessing operations include parallel grid I/O, parallel mesh partition, and parallel mesh migration, which are linked together to resolve the run-time and memory consumption bottlenecks for increasingly large grid size problems. An inverted index search strategy combined with a multi-master-slave communication paradigm is proposed to improve the pairwise face matching efficiency and reduce the communication overhead when constructing the distributed sparse graph in the phase of parallel mesh partition. And we present a simplified owner update rule to fast the procedure of raw partition boundaries migration and the building of shared faces/nodes communication mapping list between new sub-meshes with an order of magnitude of speed-up. Experiment results reveal that ParTransgrid can be easily scaled to billion-level grid CFD applications, the preparation time for parallel computing with hundreds of thousands of cores is reduced to a few minutes.     

基于VTK的CFD数据可视化Grid Service设计和实现

应用可视化工具VTK和Java在网格计算环境下实现了一个用于CFD数据后处理的高效率、易扩展、实用的可视化网格服务。网格服务接口用Web服务语言(WSDL)描述,网格服务内部实现使用VTK作为可视化内核,构建网格环境的中问件系统使用的是基于OGSA的GT3。实验结果表明,可视化网格服务可以充分利用远程强大计算资源,为性能较弱的客户端提供强大的可视化处理能力。     

基于网格技术的交通信息服务平台的设计与实现

介绍了网格技术在交通信息服务平台中的应用策略,给出了一个基于网格技术的交通信息服务平台（SHGTISP）的服务部署和信息流程及其主要模块的主要工作流程。阐述了网格中间件在SHGTISP中的应用和SHGTISP中的并行算法设计要点,以及实现SHGTISP的开发环境和系统运行环境。实践表明,网格技术能为交通信息服务平台提供高性能的计算和开放的资源共享能力。     

Economics‐inspired decentralized control approach for adaptive grid services and applications

Grid technologies facilitate innovative applications among dynamic virtual organizations, while the ability to deploy, manage, and properly remain functioning via traditional approaches has been exceeded by the complexity of the next generation of grid systems. An important method for addressing this challenge may require nature‐inspired computing paradigms. This technique will entail construction of a bottom‐up multiagent system; however, the appropriate implementation mechanism is under consideration in order for the autonomous and distributed agents to emerge as a controlled grid service or application. A credit card management service in economic interactions is considered in this article for a decentralized control approach. This consideration is based on a preliminarily developed ecological network‐based grid middleware that has features desired for the next generation grid systems. The control scheme, design, and implementation of the credit card management service are presented in detail. The simulation results show that (1) agents are accountable for their activities such as behavior invocation, service provision, and resource utilization and (2) generated services or applications adapt well to dynamically changing environments such as agent amounts as well as partial failure of agents. The approach presented herein is beneficial for building autonomous and adaptive grid applications and services. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 1269–1288, 2006.     

一种基于内存服务的内存共享网格系统

内存密集型应用对运行环境的物理内存要求严格,在物理内存不足时将会引发大量磁盘IO,降低系统性能．传统的网络内存致力于在集群内部通过共享空闲节点的物理内存解决该问题,但受集群负载和内部网络影响较大．通过结合网络内存和服务计算、网格计算等技术,提出一种基于内存服务的内存共享网格系统——内存网格,并分析和讨论了实现内存服务的关键技术和算法．内存网格弥补了网络内存的不足,扩展了网格计算的应用范围．通过基于真实应用运行状态的模拟,证明了内存网格与网络内存相比具有性能的提高．