基于折叠超立方体拓扑结构的发布订阅系统

从发布/订阅(P/S)系统的拓扑结构入手,引入基于折叠超立方体拓扑结构的发布订阅系统,并在此基础上设计相应的路由算法.折叠超立方体拓扑结构网络不仅具有结构化P2P网络的特性,能够支持大规模、动态的分布式应用;而且由于自身结构的特性使其更适合于发布/订阅系统中对大量事件传播的要求.研究及仿真结果表明,折叠超立方体结构的引入能显著降低系统负载,提高系统的扩展性和容错性能.     

基于结构化P2P 的发布订阅系统

从发布/订阅(Pub/Sub)系统的拓扑结构入手,基于结构化P2P,提出分层次的发布/订阅系统拓扑结构,将节点按处理能力分为超节点和普通节点,超节点组织形成超立方体结构,实现整个网络的广播遍历。层次式分布网络不仅具有一般P2P网络的特性,即能够支持大规模、动态的分布式应用,而且更适合于发布订阅系统中对大量事件的传播的要求。仿真结果表明,基于结构化P2P的发布订阅系统能显著降低系统负载,提高系统的可扩展性。     

内容发布订阅服务网络中的路由策略

发布/订阅系统为分布式网络中系统间的异步通讯提供了便捷的途径,事件的路由策略是基于内容发布/订阅系统的关键问题之一。文章提出了应用于内容发布/订阅服务网络中的改良后的层次形拓扑结构及先合后分的路由策略,提高了基于内容发布/订阅系统的可扩展性和传输效率。     

基于内容的发布/订阅拓扑模型设计和自配置协议研究

拓扑结构和自配置特性是实现大规模基于内容的发布/订阅系统的关键问题之一,决定了系统的可扩展性。为了提高发布/订阅系统性能,引入了空间划分的概念,设计了一个具有空间划分的层次拓扑模型。针对节点或者链路失效所带来的网络分割问题,本文在静态拓扑模型的基础上提出了一个自配置协议,提高了系统的可靠性和扩展性。     

超立方体网络连通性的概率分析

超立方体网络是大型多处理器并行计算机系统中极为重要的拓扑结构.本文使用概率分析的方法研究了在给定结点错误概率的情况下,具有子连通性的超立方体网络容错模型的连通性。理论分析和试验结果表明:在具有大量分布结点错误情况下,超立方体网络是子连通的概率非常高。     

二进制立方形递归网络的拓扑结构

二进制递归网络是一类具有良好拓扑性质和网络参数的互连网络模型.定义了一类特殊的二进制递归网络模型,即二进制立方形递归网络; 引入子网和超网的概念对其拓扑结构进行了分析研究; 证明了超立方体、扭n-立方体、广义扭立方体、交叉立方体、Mbius立方体和扭立方体连接网络都是这类特殊的二进制递归网络的具体实例.     

平衡超立方体的故障容错性

故障容错是衡量多处理器互连网络可靠性的重要方式之一。其中g-限制边连通度和g-限制连通度保证了剩下每个分支之间不连通且每个分支中节点的邻居数目不少于 g,能够更加精准地测量多处理器和多信道系统的容错性和可靠性。平衡超立方体是超立方体的一个变形,它特有的良好拓扑性质能够更好地满足多处理器系统和多种新型网络的需要。提出了n维平衡超立方体的{1,2}-限制边连通度和{1,2}-限制连通度,能够丰富以平衡超立方体为拓扑结构的网络容错性和可靠性的评价体系,并为平衡超立方体的故障诊断算法打下良好基础。     

Ad Hoc网络下的发布/订阅系统路由协议

发布/订阅系统为分布式网络中系统间的异步通讯提供了便捷的途径,事件的路由策略是基于内容的发布/订阅系统的关键问题之一。文章采用目的地动态更新与划分、逆向最短路径转发等策略,提出一种有环图下支持订阅覆盖的路由算法;通过引入订阅挂起、激活操作,以及与订阅对应的事件缓存方法,设计了一种新型的拓扑重构算法;通过引入网络分簇技术、拓扑重构算法、客户路由切换算法,设计了一种新型的面向移动Ad Hoc网络的发布/订阅系统路由协议,提高了系统的扩展性。     

超立方体网络的3路结构连通度及子结构连通度

针对以超立方体网络为蓝本的多处理机系统的可靠性和容错能力的精准度量问题，结合多处理机系统遭受计算机病毒攻击时常常发生结构性故障的特点，研究了n维超立方体网络的结构连通性和子结构连通性评价问题。首先，使用构造n维超立方体网络的3路结构割的方法得到其3路结构连通度的一个上界；然后，使用构造n维超立方体网络的3路子结构集的等价变换或约简变换的方法，得到其3路结构子连通度的一个下界；最后，利用任意网络的3路结构连通度不小于3路子结构连通度的性质，证实了超立方体网络的3路结构连通度和子结构连通度均为该超立方体网络维数的一半。这一结果表明，在3路结构故障模型下，破坏敌方以超立方体网络为底层拓扑的多处理系统至少需要攻击该系统中维数一半的3路结构或子结构。     

LHL-立方体互连网络及其性质

并行计算系统一直是计算机科学中的重要研究领域,其互连网络的拓扑性质对整个网络的性能起着非常重要的作用.目前已经提出多种互连网络,其中超立方体具有对数级的直径、高连通度、对称性等很好的性质,故被用作多种并行机的处理器连接的拓扑结构.然而,超立方体并非所有性质都是最优的互连网络,且超立方体的许多变型结构具有许多比超立方体更好的性质,其中已经证明了局部扭立方体在直径、Hamilton连通性等方面都优于超立方体.给出在超立方体与局部扭立方体的顶点间的一种连接方式--超连接,从而得到一种称为LHL-立方体的新型网络,并对这种网络的以下性质进行了研究:顶点连通度、边连通度、Hamilton连通性、直径.研究结果表明,一个n维LHL-立方体是一个具有2n个顶点和n2n-1条边的n-正则图,n维LHL-立方体的顶点连通度和边连通度均为n,且是Hamilton连通的,直径上界为[n/2 ]+3.     

RH: a versatile family of reduced hypercube interconnectionnetworks

The binary hypercube has been one of the most frequently chosen interconnection networks for parallel computers because it provides low diameter and is so robust that it can very efficiently emulate a wide variety of other frequently used networks. However, the major drawback of the hypercube is the increase in the number of communication channels for each processor with an increase in the total number of processors in the system. This drawback has a direct effect on the very large scale integration complexity of the hypercube network. This short note proposes a new topology that is produced from the hypercube by a uniform reduction in the number of edges for each node. This edge reduction technique produces networks with lower complexity than hypercubes while maintaining, to a high extent, the powerful hypercube properties. An extensive comparison of the proposed reduced hypercube (RH) topology with the conventional hypercube is included. It is also shown that several copies of the popular cube-connected cycles network can be emulated simultaneously by an RH with dilation 1     

基于比较诊断模型的超立方网络诊断算法

一个有效的诊断算法对多处理器系统而言极其重要。在多处理器系统中,识别所有故障节点的能力称为诊断系统的诊断度。在比较模型下,诊断 的执行是通过一个比较器处理器,给与之相邻的一对处理器发送相同的输入信号,并比较两者间的响应状态。为了提高超立方网络的诊断度,提出了一种新型的基于比较模型的超立方故障诊断算法,其利用超立方网络节点连接的特性生成一个拓扑图ES(k;n),最终得出一个3位二进制的诊断症候集,从而确定系统故障节点。该算法的诊断度最优能达到4n,大于传统超立方的诊断度n。     

The twisted-cube connected networks

This paper presents a new interconnection network topology,called the twisted-cube connected network,which is a generation of the twisted 3-cube.The twisted-cube connected network is a variant of the hyercube,and it has a better recursive structure.The regularity,connectivities,subgraphs of the twistedcube connected network are studied.The twisted-cube connected network is proved to be a 3-cube-free network,which is the essential difference from the hypercube and variants of the hypercube.An efficient routing algorithm is proposed,and the diameter of n-dimensional twisted-cube connected network is proved to be just[n 1/2] which is less than that of the hypercube.     

点对点网络容错路由算法的概率分析

基于网络中结点错误概率 ,提出一种新的概率分析方法 ,对网络中点对点的路由算法的容错性概率、路径长度、算法复杂性进行严格的推导 .以超立方体网络为分析的网络拓扑 ,提出在其上的一个路由算法 .分析表明 :在所有实际规模的超立方体网络中 (其结点数可以高达十亿个 ) ,在相当大的结点出错概率 (可高达 8% )的情况下 ,路由算法可达到 99.9%的成功概率     

基于多层立方体簇结构的3D-Ad hoc网络路由算法

针对三维Ad hoc网络拓扑结构复杂和节点随机移动导致寻路困难的问题,提出了基于多层立方体簇结构的路由算法。借助节点的位置信息构建多层立方体,成簇过程简便并且扩展性强;由于节点随机移动,引入了簇重构机制。利用多层立方体簇进行拓扑转化及簇间通信编号。簇间通信编号能够提供到达地址的相关路径信息,有效简化了路由过程。仿真分析表明,提出的策略正确可行,达到了简化三维Ad hoc网络拓扑、正确路由的目的。     

A distributed virtual hypercube algorithm for maintaining scalable and dynamic network overlays

Network overlays support the execution of distributed applications, hiding lower level protocols and the physical topology. This work presents DiVHA: a distributed virtual hypercube algorithm that allows the construction and maintenance of a self‐healing overlay network based on a virtual hypercube. DiVHA keeps logarithmic properties even when the number of nodes is not a power of two, presenting a scalable alternative to connect distributed resources. DiVHA assumes a dynamic fault situation, in which nodes fail and recover continuously, leaving and joining the system. The algorithm is formally specified, and the latency for detecting changes and the subsequent reconstruction of the topology is proved to be bounded. An actual overlay network based on DiVHA called HyperBone was implemented and deployed in the PlanetLab. HyperBone offers services such as monitoring and routing, allowing the execution Grid applications across the Internet. HyperBone also includes a procedure for detecting groups of stable nodes, which allowed the execution of parallel applications on a virtual hypercube built on top of PlanetLab. Copyright © 2014 John Wiley & Sons, Ltd.     

On a class of recursive network topologies

For the interconnection of the nodes of massively parallel processor networks, concepts are required, which are extendable. In this paper, a ‘recursive network’ is described. With a basic building block, essentially with a fixed number of links, arbitrarily large systems can be configured. At all levels, the interconnection topology is the same. Hence, a simple routing algorithm can be applied. The recursive network is described and compared with hypercube and mesh networks (with respect to the system diameter and the efficient use of the links).     

Adaptive routing in wormhole-switched necklace-cubes: Analytical modelling and performance comparison

The necklace hypercube has recently been introduced as an attractive alternative to the well-known hypercube. Previous research on this network topology has mainly focused on topological properties, VLSI and algorithmic aspects of this network. Several analytical models have been proposed in the literature for different interconnection networks, as the most cost-effective tools to evaluate the performance merits of such systems. This paper proposes an analytical performance model to predict message latency in wormhole-switched necklace hypercube interconnection networks with fully adaptive routing. The analysis focuses on a fully adaptive routing algorithm which has been shown to be the most effective for necklace hypercube networks. The results obtained from simulation experiments confirm that the proposed model exhibits a good accuracy under different operating conditions.