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基于数据网格面向服务的查询算法 总被引:1,自引:0,他引:1
面向服务的框架(SOA)为用户的服务提供了一个标准的平台,实现服务的提供、发现、配置和集成,以帮助用户查询和处理信息.数据网格是面向服务的架构,为用户进行分布式远程数据查询服务提供了保障.对网格环境下Hidden Web数据库的研究与开发逐渐成为人们关注的焦点问题.要回答用户的查询,数据集成系统需要解决网格上的需求语义分析和关键字查询、建立数据查询模型.将数据库抽象为无向图,节点对应数据库中的元组,边对应“主-外码”的关系.查询的结果是与元组连接的答案树,它与查询的关键字相匹配.针对以上这些问题提出了一个新的查询算法,将改进的动态规划算法用于查询模型,保证Top-1答案树最优,Top-K答案树近似最优;给出了实验测试和评估结果. 相似文献
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流媒体网格系统信息服务需要整合网格系统中各种静态、动态的资源信息,提供统一的信息访问接口.Globus MDS提供了一种网格信息服务系统,适用于计算网格的信息服务,但不能完全适用于流媒体网格.介绍了Globus的信息服务模型,讨论如何基于Globus MDS构建适合流媒体网格的信息服务系统.针对Globus MDS的层次式查询机制,使用信息缓存和哈希查询技术对其进行改进.实验表明,改进的查询机制可以提高信息的查询效率,满足实时流媒体服务要求. 相似文献
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网格计算环境中的资源具有海量性、分布性、异构性、自治性、动态性等特点。因此资源信息服务成为网格软件的关键技术之一。本文主要研究使用元计算目录服务MDS(Metacomputing Directory Service)构建网格系统软件中的资源信息服务,完成对网格计算环境中的信息的发现、注册、查询、修改等工作,提供对网格计算环境的一个真实、实时的动态反映.MDS的内容主要包括资源发现、资源描述和资源监视与更新。MDS在实现上主要使用轻量目录访问协议LDAP(Lightweight Directory Access Protocol)作为网格信息访问和存储的统一界面。 相似文献
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网格的资源管理是网格计算系统的必要基础,它及时地收集网格资源的信息,并提供整个网格的统一资源信息视图。对于具有大科学、多单位合作特色的高能物理研究,网格计算将提供一个强大的计算技术支持。着重说明了网格计算资源动态管理系统的设计原理和总体结构,以及基于网络的信息查询、修改服务。 相似文献
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ChinaGrid图像处理网格平台中的语义信息服务研究 总被引:2,自引:0,他引:2
在网格中要实现更加准确有效的服务发现、查询及其动态分配和替换,需要在语法匹配的基础上进一步实现语义匹配.介绍了在图像处理网格平台上开发的、基于语义的信息服务组件;描述了该组件的设计框架结构,并给出该组件的核心算法即网格服务语义匹配算法的描述.该组件能有效实现对图像处理网格服务的语义查询和工作流构建时的自动语义匹配以及工作流执行中网格服务的动态分配和替换.与传统语义服务匹配算法相比,所提出的网格服务匹配算法显著提高了网格服务的匹配准确度. 相似文献
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不同种类的服务的绑定、共享、组合,协同操作成为系统集成的关键,使得服务网格化成为一种需求.服务网格发现是服务重用、组合的前提.采用语义匹配来解决基于关键字匹配的低效问题,服务发现结构的研究是为了缩短服务发现的响应时间,并充分利用语义信息提高服务查询效率.服务发现结构的两层P2P结构中增加了目录服务改进两阶段服务匹配算法,充分利用目录服务减少服务请求的转发次数以达到缩短服务发现时间. 相似文献
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A super-peer model for resource discovery services in large-scale Grids 总被引:12,自引:0,他引:12
Carlo Mastroianni Domenico Talia Oreste Verta 《Future Generation Computer Systems》2005,21(8):440-1248
As deployed Grids increase from tens to thousands of nodes, peer-to-peer (P2P) techniques and protocols can be used to implement scalable services and applications. The super-peer model is a novel approach that helps the convergence of P2P models and Grid environments and can be used to deploy a P2P information service in Grids. A super-peer serves a single physical organization in a Grid, and manages metadata associated to the resources provided by the nodes of that organization. Super-peers connect to each other to form a peer network at a higher level. This paper examines how the super-peer model can handle membership management and resource discovery services in a multi-organizational Grid. A simulation analysis evaluates the performance of a resource discovery protocol; simulation results can be used to tune protocol parameters in order to increase search efficiency. 相似文献
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文中描述了基于网格BSP系统BSP-G的设计和实现。BSP-G并行库利用网格中间件GlobusToolkit2.0提供的各种网格协议和服务,进行进程启动、监视、控制、身份认证、授权、资源分配、可执行程序的自动传送(Stage)。它使得用户能够在网格上直接运行BSP程序而无需关心网格接口的一些细节问题。最后给出了BSP-G的测试结果。 相似文献
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普适计算环境下,环境的结构、组成以及环境中的资源、服务都是动态变化的,而服务发现技术能够在动态变化的普适计算环境中动态查找、定位所需的服务,是解决普适计算环境异构性、实现不同应用集成的有效途径,因此逐渐成为普适计算中研究的一个热点和重点。基于此,本文总结、分析了当前已有的比较著名的普适计算服务发现协议并进行了分类比较,总结了各个方向上目前的研究进展,在此基础之上对今后的研究趋势进行了分析与展望。 相似文献
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Feng ZHU Anish BIVALKAR Abdullah DEMIR Yue LU Chockalingam CHIDAMBARM Matt MUTKA 《Frontiers of Computer Science》2010,4(3):311
With the advances in and convergence of Internet technologies, embedded computers, and wireless communication, computing devices have become part of our daily life. Hand-held devices and sensors with wireless connections create opportunities for many new nomadic applications. Service discovery is an essential component for cognitive science to discover existing network services just-in-time. Unlike many other approaches, we propose a service discovery model supporting nomadic users and services in public environments. Our model emphasizes secure and private service discovery in such environments. Location sensing is integrated for location dependent service discovery and is used to lessen service discovery network infrastructure requirements. We analyze the system performance and show our formal verification of the protocols. Our implementation shows that our model is feasible. 相似文献
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Nut Xinran Andrew A. Atul Bridget Debi Thomas Dane Graham John 《Future Generation Computer Systems》2006,22(8):955-963
Collaborative visualization of large-scale datasets across geographically distributed sites is becoming increasingly important for Earth Sciences. Not only does it enhance our understanding of the geological systems, but also enables near-real-time scientific data acquisition and exploration across distant locations. While such a collaborative environment is feasible with advanced optical networks and resource sharing in the form of Grid, many technical challenges remain: (1) on-demand discovery, selection and configuration of supporting end and network resources; (2) construction of applications on heterogeneous, distributed environments; and (3) use of novel exotic transport protocols to achieve high performance. To address these issues, we describe the multi-layered OptIPuter middleware technologies, including simple resource abstractions, dynamic network provisioning, and novel data transport services. In this paper, we present an evaluation of the first integrated prototype of the OptIPuter system software recently demonstrated at iGrid 2005, which successfully supports real-time collaborative visualizations of 3D multi-gigabyte earth science datasets. 相似文献
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由于缺少GPS通信服务标准,不同的GPS监控设备在GPRS上传输的数据通信协议有较大差别,这给综合性的GPS监控信息接入带来了困难,协议版本的不断变化也加剧了数据分析的困难。基于有限自动机模型,设计了一种自动协议分析算法,能够实现一套程序同时对多种协议进行分析和转换。 相似文献
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This paper focuses on resource discovery problem for Grid. Grid is a devices and services environment that has evolved with the goal of resource sharing. Grid resource discovery encompasses locating and retrieving computational resources. Existing resource discovery solutions are not well adapted to the dynamicity and heterogeneity of Grid. Query propagation is a novel approach that forwards an unsupported query from its resident peer to an adjacent peer. The concept of next generation intelligent Grid environments needs intelligent modules for resource discovery. Learning automaton is a stochastic tool with learning ability which simply adapts to the progressive environmental changes. The proposed method utilizes a distributed learning automata (DLA) which is a network of learning automata (LA). Here, multiple DLA are used for forwarding domain-specific queries. Different Grid scales are utilized for evaluation of the proposed method. Results demonstrate that the resource discovery based on DLA optimizes resource utilization, maximizes throughput, minimizes response time and avoids overload. Moreover, the algorithm is also scalable, fully distributed and failure-free. 相似文献