基于DHT的P2P系统的负载均衡算法

在基于DHT的结构化P2P系统中,DHT的使用以及节点处理能力的不同导致系统中节点的负载不均衡.现有的负载均衡算法存在两个不足：①负载的转移没有考虑节点之间的链路延迟;②算法依赖于系统中固定位置的某些节点.提出了分布式负载均衡算法：每个节点周期性的收集系统局部负载信息,然后选择链路延迟较小的节点进行负载转移.算法依赖于系统中的所有节点,解决了单点失败问题.同时,负载的转移是在链路延迟较小的节点之间进行的.仿真实验表明,①对于各种系统利用率,该算法都可以获得理想的负载均衡效果;②算法可以使负载转移开销减少45%以上.     

一种结构化P2P网络动态负载均衡算法的研究

负载均衡是P2P网络的研究热点之一,当前负载均衡技术存在负载均衡程度低、假设条件过多等问题.提出一了种增强型负载均衡算法ELB_P2P,它根据节点的承栽能力为其分配相应大小的可动态调整的ID地址空间以及合理的载荷,在负载转移时自动选择延迟小带宽高的轻栽节点,并引入负载转移流量控制机制.实验表明,相对于Chord等传统P2P协议,ELB_P2P算法有更快的负载均衡速度、更小的负载均衡开销,系统稳定性好,在网络重栽情况下也能取得较低的负载不平衡度,并且对节点属性没有苛刻的限制和假定.     

一种结构化P2P负载均衡策略的研究

热点对象是影响P2P系统负栽均衡的一个重要方面.含有热点对象的节步不但本身成为高请求负载的节点,同时使路由路径上的节点成为高路由负栽节点.本文利用Pastry系统路由表选择性,提出了一种动态路由表的思想,减轻高负载节点路由路径上的路由负载.经实验证明,该算法有效地解决了结构化P2P系统中因热点对象引发的路由负载均衡问题.     

基于P2P系统的动态负载均衡算法

在现实的P2P网络环境中,由于节点的计算能力和带宽等方面的异构性,网络负载不均衡现象非常突出.基于数据复制/转移策略,提出一种动态的平衡算法.根据节点的能力,当前节点负载状态、负载转移代价预估算,在整个系统范围内找到一组传输代价较小并且负载较轻的节点集合,从中随机选取较为适宜的节点进行负载转移或者数据复制.试验结果表明,该算法能够有效地均衡负载的分布以及降低负载的迁移率.     

基于DHT的P2P系统负载均衡算法

负载不均衡是影响P2P系统应用服务器性能的关键因素之一,目前研究主要集中在基于flat DHT（Distributed Hashing Table）的P2P系统模型上。将分布式负载均衡算法结合虚拟服务器技术的优势相结合。设置双阈值以解决不必要的节点间通信问题;并在热区迁移中采用隔层负载迁移策略,以期减少不必要的反复的负载迁移。仿真实验结果表明,算法保证负载在各节点上趋于公平并使热区的次数明显减少。     

基于结构化P2P网络的动态负载均衡算法研究

针对结构化P2P网络中可能出现的查找"热点"问题,结合基于DHT的P2P系统路由机制提出了ADLB(adaptive dy namic load balancing)算法,该算法充分利用原有Chord[4]协议的路由机制和P2P网络中各节点的异质性,通过动态控制节点加入来减轻重载节点的负载.此外还提出了一套动态监测控制节点负载的方法,最后通过性能仿真验证了算法的有效性.     

一种新的结构化对等网负载均衡算法

研究结构化对等网(P2P)中的负载均衡问题,P2P网络的节点、延迟和处理能力差异性很大,当前负载均衡算法忽略节点差异性,造成网络负载极不平衡,容易出现"热点"问题,使负载变化大。为了更好的均衡P2P负载,提出一种新的网络负载均衡算法。算法充分考虑节点之间的差异性,对物理节点的地址空间进行动态分配,对于热点资源下载采用局部搜索算法找到邻居节点,并自动把负载转移到轻载节点上,保证节点间负载均衡。仿真结果表明,新网络负载均衡算法加快了负载均衡速度,使P2P网络负载均衡更加均衡,能够很好保持系统稳定性。     

结构化P2P系统中基于网络定位的负载均衡算法*

结构化P2P系统中,各对等节点处理能力的差异以及关键字通常与一定的语义相关,导致系统中节点的负载不均衡。算法针对基于DHT的大规模计算网络中,计算任务在节点间分布不均衡的问题,提出了一种高效的基于网络定位的负载均衡算法：当某个节点的负载较小时,它将以自己为中心,与物理位置相近的节点构成一个星型结构区域,然后在这个物理位置相近的区域进行负载转移。该算法具有扩展性好、效率高、维护简单的特点。仿真实验表明本算法可以达到理想的负载均衡效果,并使负载转移开销减少了40%以上。     

基于Linux虚拟服务器的负载均衡算法

分析Linux虚拟服务器负载均衡调度过程,提出一种基于Linux虚拟服务器的负载均衡算法。该算法结合系统资源类型和服务器权重系数,依据服务器加权负载标准差,进行集群真实服务器负载状况分析,动态调整服务器权重系数,对改进的最小连接数调度算法进行负载均衡调度。测试结果验证了该算法的有效性。     

传输受限的异构P2P系统负载平衡算法

提出了一种传输受限的异构P2P负载平衡算法,此算法依赖于局部网络的负载信息,并在局部网络内部进行负载迁移使整个系统达到负载平衡状态。理论分析和实验数据均表明,此算法可在网络传输存在限制的条件下,尽快地使系统到达平衡状态。基于局部负载信息与基于全局负载信息的负载平衡效果几乎相同,而前者的时间复杂度远低于后者,特别是在节点较多的P2P网络中。同时由于在局部网络内进行负载迁移,故能够以较小的网络通信量得到良好的性能。     

基于局部网络信息的P2P系统负载平衡算法

提出了一种基于P2P网络局部信息的负载平衡算法,该算法依赖于局部网络的负载信息,并在局部网络内部进行负载迁移使整个系统达到负载平衡状态。理论分析和实验数据均表明,该算法可在网络传输存在限制的条件下,尽快地使系统到达平衡状态。基于局部负载信息与基于全局负载信息的负载平衡效果几乎相同,而前者的时间复杂度远低于后者,特别是在节点较多的P2P网络中。同时由于在局部网络内进行负载迁移,故能够以较小的网络通信量得到良好的性能。     

An optimal inherently stabilizing routing algorithm for star P2P overlay networks

Star graphs possess many desirable properties such as scalable node degrees and diameters, which are essential to facilitate reduced routing table sizes and low maximum path length for routing in large P2P networks. In addition, because a large number of disjoint paths are available and each data/replica in an n‐star can be placed in an (n − 1)‐star, load balancing and alleviation of network bottlenecks can be implemented in star P2P overlay networks. Therefore, star networks have been proposed as viable alternatives to existing overlay topologies for large P2P networks. In this paper, we propose an optimal stabilizing and inherently stabilizing algorithm for routing messages over all disjoint paths between two peers in a star P2P overlay network. The algorithm is optimal in terms of its time complexity in rounds and the length of the longest path traversed by the messages, and fault tolerant due to being stabilizing and inherently stabilizing, allowing the system to withstand transient faults. The algorithm can be used to increase network reliability and survivability in P2P networks. In addition, the usage of all disjoint paths to route messages between two peers leads to increased network bandwidth while distributing the communication overhead across the network and eliminating network bottlenecks in P2P networks. Copyright © 2016 John Wiley & Sons, Ltd.     

DisCoP2P: an efficient P2P computing overlay

CodiP2P and DisCoP are two peer-to-peer (P2P) computing overlays aimed at sharing computing resources (CPU, Memory, etc.) to execute parallel applications. Their component nodes are basically PC’s and a wide range of computer servers, desktops or laptops. This paper joins these two platforms into a new one, DisCoP2P, to combine the features from both overlays. CodiP2P is highly scalable, and DisCoP has an efficient searching mechanism and the ability to classify computing resources. The new platform takes advantage of these features and uses them to offer new facilities to schedule and execute parallel applications efficiently. This is accomplished at null cost because the platform is made up of nodes that share resources for free. This research field can also be classified in desktop computing. The success of this platform depends greatly on the added overhead. This overhead is produced mainly in searching for resources and system administration. The obtained results in a preliminary prototype, although not sufficiently conclusive, demonstrate the applicability of DisCoP2P in the real world, i.e. Internet.     

P2P视频直播数据调度算法

P2P技术解决了传统流媒体应用中的不能支持大用户的问题.而数据调度算法一直是P2P研究中的热点问题.在给出了P2P视频直播系统中节点能力的定义和计算方法后,结合BT中的Rarest First策略,提出了一种基于节点能力的适用于P2P视频直播系统的数据调度算法.该算法既考虑了流媒体数据具有时间限制的特性,同时也考虑了如何能充分的利用节点的上传带宽,增进了系统的负载平衡.     

P2P覆盖网中的聚类研究综述*

首先对P2P覆盖网中的聚类技术进行了分类,在此基础上介绍了各种典型的聚类方法并进行了对比分析;最后指出了P2P覆盖网中聚类技术的未来研究趋势。     

TCR: a trustworthy and churn-resilient academic distribution and retrieval system in P2P networks

As the number of people using the internet has surged over the past few years, more and more people are choosing to share and retrieve information online. There are several decentralized retrieval applications that provide file-sharing platforms for exactly this purpose. However, these applications cannot guarantee churn resilience, trustworthiness, or low cost of retrieval. Therefore, in this paper, we present a system called trustworthy and churn-resilient academic distribution and retrieval system in P2P networks, or TCR, which: (1) ensures that information will not be centralized by central network administrators; (2) utilizes LSH to classify nodes with similar research topics into a local subnetwork, and applies routing algorithms with trust score equations to determine the next trustworthy node to forward the message, thus ensuring each node can accurately and efficiently find its trustworthy nodes within only a few hops; (3) provides a trustworthy management system that itself deals in trustworthiness, ensuring that even when there is a large proportion of malicious nodes, the system can still detect and punish misbehaving nodes; (4) guarantees that nodes can still retrieve the desired files even when in high-churn networks. We finally demonstrate that our TCR entails low message costs, provides high match rates, detects malicious nodes, and ensures churn resilience and search efficiency when compared to other P2P retrieval systems.