Structured P2P Research Articles

Research and improvement of streaming media system based on Gossip protocol

The Gossip-based P2P streaming media system has become the mainstream of P2P streaming media systems.But the inherent drawbacks of Gossip protocol—the randomness and uncertainties of data dissemination influence the P2P streaming media system.Based on the Gossip,an approach combining unstructured and structured P2P network was proposed to cover the shortage of the data dissemination based on Gossip and improve the efficiency of streaming media system.Finally the approach has been proved to be reliable through simulation.

Leveraging Identity-Based Cryptography for Node ID Assignment in Structured P2P Systems

Structured peer-to-peer (P2P) systems have grown enormously because of their scalability, efficiency, and reliability. These systems assign a unique identifier to each user and object. However, current assignment schemes allow an adversary to carefully select user IDs and/or simultaneously obtain many pseudo-identities-ultimately leading to an ability to disrupt the P2P system in very targeted and dangerous ways. In this paper, we propose novel ID assignment protocols based on identity-based cryptography. This approach permits the acquisition of node IDs to be tightly regulated without many of the complexities and costs associated with traditional certificate solutions. We broadly consider the security requirements of ID assignment and present three protocols representing distinct threat and trust models. A detailed empirical study of the protocols is given. Our analysis shows that the cost of our identity-based protocols is nominal, and that the associated identity services can scale to millions of users using a limited number of servers.

Computing and Routing for Trust in Structured P2P Network

Study of trust in P2P network now is focus on how to effectively against various malicious behaviors such as providing fake or misleading feedback about other peers and the management of trust in a P2P environment. But the scotoma of portability that trust peer can join (leave) a certain P2P network at anytime and anywhere is seldom discussed. In this paper, a structured topology for trusts management in portable P2P network based on DHT (discrete hash table) is proposed first, in which includes trust management strategies and peer operations on certain DHT circle. After that, a novel trust-computing model for the structured P2P network and the main trust decisions in the structured network are introduced too. Effectiveness and practicality of the proposed trust management have been showed in simulation experiments at the end.

Node-Capability-Aware Replica Management for Peer-to-Peer Grids

Data objects have to be replicated in large-scale distributed systems for reasons of fault tolerance, availability, and performance. Furthermore, computations may have to be scheduled on these objects, when these objects are part of a grid computation. Although replication mechanism for unstructured peer-to-peer (P2P) systems can place replicas on capable nodes, they may not be able to provide deterministic guarantees on searching. Replication mechanisms in structured P2P systems provide deterministic guarantees on searching but do not address node capability in replica placement. We propose Virat, a node-capability-aware P2P middleware for managing replicas in large-scale distributed systems. Virat uses a unique two-layered architecture that builds a structured overlay over an unstructured P2P layer, combining the advantages of both structured and unstructured P2P systems. Detailed performance comparison is made with a replication mechanism realized over OpenDHT, a state-of-the-art structured P2P system. We show that the 99th percentile response time for Virat does not exceed 600 ms, whereas for OpenDHT, it goes beyond 2000 ms in our test bed, created specifically for the aforementioned comparison.

New constant-degree P2P system based on DBR

This paper proposed a new constant-degree graph, DBR, which combined De Bruijn and Ring and kept 2 in-degrees and 2 out-degrees of a node. Adapting DBR to the dynamic network, we designed Tangram with constant-degree. Tangram was based on DHT. It was a scalable, completely decentralized and self-organizing structured P2P system. The routing algorithm of Tangram was composed of De Bruijn algorithm and Chord algorithm and achieved a time complexity of O(log N) per lookup request by using O(1) neighbors per node, where N was the network size. Experimental results show that Tangram is efficient.

Histogram-Based Global Load Balancing in Structured Peer-to-Peer Systems

Over the past few years, peer-to-peer (P2P) systems have rapidly grown in popularity and have become a dominant means for sharing resources. In these systems, load balancing is a key challenge because nodes are often heterogeneous. While several load-balancing schemes have been proposed in the literature, these solutions are typically ad hoc, heuristic based, and localized. In this paper, we present a general framework, HiGLOB, for global load balancing in structured P2P systems. Each node in HiGLOB has two key components: 1) a histogram manager maintains a histogram that reflects a global view of the distribution of the load in the system, and 2) a load-balancing manager that redistributes the load whenever the node becomes overloaded or underloaded. We exploit the routing metadata to partition the P2P network into nonoverlapping regions corresponding to the histogram buckets. We propose mechanisms to keep the cost of constructing and maintaining the histograms low. We further show that our scheme can control and bound the amount of load imbalance across the system. Finally, we demonstrate the effectiveness of HiGLOB by instantiating it over three existing structured P2P systems: Skip Graph, BATON, and Chord. Our experimental results indicate that our approach works well in practice.

Self-Adaptive Load Balancing Method in Structured P2P Protocol

PDF HTML阅读 XML下载 导出引用 引用提醒 一种结构化P2P 协议中的自适应负载均衡方法 DOI: 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: Supported by the National Natural Science Foundation of China under Grant No.60673156 (国家自然科学基金); the Key Project ofthe Ministry of Education of China under Grant No.105129 (教育部科学技术研究重点项目) Self-Adaptive Load Balancing Method in Structured P2P Protocol Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:提出一种自适应负载均衡方法,方法采用一种被动式结点负载统计方法生成局部负载视图;一种文件访问统计方法生成局部文件访问视图;当系统内结点负载存在差异时,重载结点把指向自身的逻辑链路迁移至指向局部负载视图中的轻载结点,通过减小重载结点入度和增加轻载结点入度来减小结点间负载差异;当结点的请求负载较高时,通过局部文件访问视图计算需要缓存的热点文件及目标结点,降低承载热点文件的结点请求负载.实验结果表明,在用户查询服从Zipf 分布的环境下,自适应负载均衡方法可使系统负载达到较好的均衡;缓存方法虽然在一定程度上增加了缓存和更新开销,但在一定条件下比查询消息命中缓存节省的网络开销要小,降低了系统的整体负载. Abstract:This paper presents a self-adaptive load balancing algorithm, in which each node creates a local load distribution view with a passive load statistic method and a local file requested view with a file requested statisticmethod. When the load imbalance exists in the system, the heavily loaded node will make the logical links pointingto itself point to a lighty loaded node in its local load distribution view, with the indegree of the heavy loaded nodedecreasing and that of the lighty loaded node increasing, the load imbalance magnitude will decrease. When therequest load of the heavy loaded node is high, the node will use its local file request view to get the popular file andcache the file to corresponding target node. Results from simulation experiments indicate that the system has a good load balance under Zipf-like requests distribution if it runs the self adaptive load balancing algorithm. To someextent, caching requires some extra messages, but fewer than the cache hit messages under some condition, socaching can reduce the overall load of the system. 参考文献 相似文献 引证文献

Structured P2P technologies for distributed command and control

The utility of Peer-to-Peer (P2P) systems extends far beyond traditional file sharing. This paper provides an overview of how P2P systems are capable of providing robust command and control for Distributed Multi-Agent Systems (DMASs). Specifically, this article presents the evolution of P2P architectures to date by discussing supporting technologies and applicability of each generation of P2P systems. It provides a detailed survey of fundamental design approaches found in modern large-scale P2P systems highlighting design considerations for building and deploying scalable P2P applications. The survey includes unstructured P2P systems, content retrieval systems, communications structured P2P systems, flat structured P2P systems and finally Hierarchical Peer-to-Peer (HP2P) overlays. It concludes with a presentation of design tradeoffs and opportunities for future research into P2P overlay systems.

Dynamic Web Service discovery architecture based on a novel peer based overlay network

Service Oriented Computing and its most famous implementation technology Web Services (WS) are becoming an important enabler of networked business models. Discovery mechanisms are a critical factor to the overall utility of Web Services. So far, discovery mechanisms based on the UDDI standard rely on many centralized and area-specific directories, which poses information stress problems such as performance bottlenecks and fault tolerance. In this context, decentralized approaches based on Peer to Peer overlay networks have been proposed by many researchers as a solution. In this paper, we propose a new structured P2P overlay network infrastructure designed for Web Services Discovery. We present theoretical analysis backed up by experimental results, showing that the proposed solution outperforms popular decentralized infrastructures for web discovery, Chord (and some of its successors), BATON (and it’s successor) and Skip-Graphs.

A Virtual Ring Method for Building Small-World Structured P2P Overlays

This paper presents a general virtual ring method to design and analyze small-world structured P2P networks on the base topologies embedded in ID spaces with distance metric. Its basic idea is to abstract a virtual ring from the base topology according to the distance metric, then build small-world long links in the virtual ring and map the links back onto the real network to construct the small-world routing tables for achieving logarithmic greedy routing efficiency. Four properties are proposed to characterize the base topologies that can be turned into small-world by the virtual ring method. The virtual ring method is applied to the base topologies of d-torus with Manhattan distance, high dimensional d-torus base topologies, and other base topologies including the unbalanced d-torus and the ring topology with tree distance. Theoretical analysis and simulation experiments demonstrate the efficiency and the resilience of the proposed overlays.

GossipTrust for Fast Reputation Aggregation in Peer-to-Peer Networks

In peer-to-peer (P2P) networks, reputation aggregation and ranking are the most time-consuming and space-demanding operations. This paper proposes a new gossip protocol for fast score aggregation. We developed a Bloom filter architecture for efficient score ranking. These techniques do not require any secure hashing or fast lookup mechanism, thus are applicable to both unstructured and structured P2P networks. We report the design principles and performance results of a simulated GossipTrust reputation system. Randomized gossiping with effective use of power nodes enables light-weight aggregation and fast dissemination of global scores in O(log <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> n) time steps, where n is the P2P network size. The Gossip-based protocol is designed to tolerate dynamic peer joining and departure, as well as to avoid possible peer collusions. The scheme has a considerably low gossiping message overhead, i.e. O(n log <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> n) messages for n nodes. Bloom filters demand at most 512 KB memory per node for a 10,000-node network. We evaluate the performance of GossipTrust with distributed P2P file-sharing and parameter-sweeping applications. The simulation results demonstrate that GossipTrust has small aggregation time, low memory demand, and high ranking accuracy. These results suggest promising advantages of using the GossipTrust system for trusted P2P applications.

P 3 N

A large number of peer-to-peer (P2P) networks have been introduced in the literature since their popular advent in the late 1990s. In particular, structured P2P overlays have gained much attention since 2001. They are noted mainly for their theoretical properties such as balancing of communication, storage and processing load, as well as elegance of design.

A structured P2P network based on the small world phenomenon

In this paper, we propose a new structured P2P overlay network, named SW-Uinta(small-world). In order to reduce the routing latency, we firstly construct the Uinta network in which both physical characteristics of network and data semantic are considered. Furthermore, based on Uinta, a nondeterministic caching strategy is employed to allow for poly-logarithmic search time while having only a constant cache size. Compared with the deterministic caching strategy proposed by previous P2P systems, the nondeterministic caching strategy can reduce communication overhead for maintaining the routing cache table. Cache entries in the cache table of peer nodes can be updated by subsequent queries rather than only by running stabilization periodically. In the following, a novel cache replacement scheme, named the SW cache replacement scheme, is used to improve lookup performance, which has proved to satisfy the small-world principle. So we call this network SW-Uinta(small-world). After that, according to the theoretical analysis, it can be proved that SW-Uinta(small-world) can get O((log?2 N)/k) search time with O(k) cache size. Lastly, the performance of SW-Uinta(small-world) is compared with those of other structured P2P networks such as Chord and Uinta. It shows that SW-Uinta(small-world) can achieve improved object lookup performance and reduce maintenance cost.

A P2P-based intelligent resource discovery mechanism in Internet-based distributed systems

Internet-based distributed systems enable globally-scattered resources to be collectively pooled and used in a cooperative manner to achieve unprecedented petascale supercomputing capabilities. Numerous resource discovery approaches have been proposed to help achieve this goal. To report or discover a multi-attribute resource, most approaches use multiple messages, with one message for each attribute, leading to high overhead of memory consumption, node communication, and subsequent merging operation. Another approach can report and discover a multi-attribute resource using one query by reducing multi-attribute to a single index, but it is not practically effective in an environment with a large number of different resource attributes. Furthermore, few approaches are able to locate resources geographically close to the requesters, which is critical to system performance. This paper presents a P2P-based intelligent resource discovery (PIRD) mechanism that weaves all attributes into a set of indices using locality sensitive hashing, and then maps the indices to a structured P2P overlay. PIRD can discover resources geographically close to requesters by relying on a hierarchical P2P structure. It significantly reduces overhead and improves search efficiency and effectiveness in resource discovery. It further incorporates the Lempel–Ziv–Welch algorithm to compress attribute information for higher efficiency. Theoretical analysis and simulation results demonstrate the efficiency of PIRD in comparison with other approaches. It dramatically reduces overhead and yields significant improvements on the efficiency of resource discovery.

Effect of heterogeneity on static load balance algorithm performance in DHT systems

Application layer peer to peer (P2P) network technology is widely regarded as the most important development for next generation Internet infra‐structure. For these systems to be effective, load balancing among the peers is critical. Early structured P2P systems rely on the randomness of object ID generated with a dynamic hash function to avoid the load imbalance issue. This has been known to result in an imbalance factor of O (log N) in the number of items stored at a node. This paper makes two contributions. First, based on previous work, we propose a simple yet extremely effective extension. We demonstrate the superior performance of our proposal and also explore other important issues vital to the performance for the virtual server framework, such as the effect of the number of directories employed in the system, and the performance ramification of user registration strategies. Secondly, and more significantly, we characterize systematically the effect of heterogeneity on load balancing algorithm performance, and the conditions in which heterogeneity may be easy or hard to deal with. We show how previous results may be valid only in the simpler settings.

The Server Reassignment Problem for Load Balancing in Structured P2P Systems

Application-layer peer-to-peer (P2P) networks are considered to be the most important development for next-generation Internet infrastructure. For these systems to be effective, load balancing among the peers is critical. Most structured P2P systems rely on ID-space partitioning schemes to solve the load imbalance problem and have been known to result in an imbalance factor of ominus(logN) in the zone sizes. This paper makes two contributions. First, we propose addressing the virtual-server-based load balancing problem systematically using an optimization-based approach and derive an effective algorithm to rearrange loads among the peers. We demonstrate the superior performance of our proposal in general and its advantages over previous strategies in particular. We also explore other important issues vital to the performance in the virtual server framework, such as the effect of the number of directories employed in the system and the performance ramification of user registration strategies. Second, and perhaps more significantly, we systematically characterize the effect of heterogeneity on load balancing algorithm performance and the conditions in which heterogeneity may be easy or hard to deal with based on an extensive study of a wide spectrum of load and capacity scenarios.

HRing: A Structured P2P Overlay Based on Harmonic Series

This paper presents Harmonic Ring (HRing), a structured peer-to-peer (P2P) overlay where long links are built along the ring with decreasing probabilities coinciding with the Harmonic Series. HRing constructs routing tables based on the distance between node positions instead of node IDs in order to eliminate the effect of node ID distribution on the long link distribution and load balance. It supports leave-and-rejoin load balance without incurring uneven long link distribution. In addition, node IDs can be any form, like number, string, address, and date, without the prerequisite of uniform distribution, so they can preserve the semantics and range locality of data objects. HRing supports multidimensional range queries. Each node is expected to have O(ln(n)) long links. The construction of O(ln(n)) long links for a node costs (O(ln(n)) messages. Routing queries achieve O(ln(n)) hops. Analyses and simulations demonstrate the efficiency of query routing and the effectiveness of the long link construction method.

Special Interest Messaging: A Comparison of IGM Approaches

Hundreds of technical, special interest Internet weblogs are already generating thousands of niche articles worldwide, and many institutions are starting to create internal blogs for team collaboration. As this style of communication becomes more pervasive in the lives of employees and researchers, the difficulty of finding relevant information only grows with the number of authors and articles. To reduce the load, we propose using implicit group messaging (IGM) to automatically deliver relevant content to readers grouped by shared characteristics or interests. In this paper, we outline a context-aware application suited to special interest messaging and describe three alternative delivery models including our peer-to-peer (P2P) design called SPICE and a broker-based design. We investigate the advantages and disadvantages of each approach through detailed simulations driven by realistic data and actual national/global network topologies. We find that although a broker-based design is generally the most network efficient and lowest latency, a structured P2P system can offer exceptionally low and fair loading across peers and network links without relying on specialized broker nodes.

Message Passing in Semantic Peer-to-Peer Overlay Networks [Exploratory DSP

In this column, we discuss exploratory research related to data management in P2P overlay networks. First, we discuss the notions of unstructured and structured P2P overlay networks. Then, we discuss data management in such networks by introducing an additional layer to handle semantic heterogeneity and data integration. Finally, we present a method based on sum-product message passing to detect inconsistent information in this setting.

Assisted Peer-to-Peer Search with Partial Indexing

In the past few years, peer-to-peer (P2P) networks have become a promising paradigm for building a wide variety of distributed systems and applications. The most popular P2P application till today is file sharing, e.g., Gnutella, Kazza, etc. These systems are usually referred to as unstructured, and search in unstructured P2P networks usually involves flooding or random walking. On the other hand, in structured P2P networks (DHTs), search is usually performed by looking up a distributed inverted index. The efficiency of the search mechanism is the key to the scalability of a P2P content sharing system. So far, neither unstructured nor structured P2P networks alone can solve the search problem in a satisfactory way. In this paper, we propose to combine the strengths of both unstructured and structured P2P networks to achieve more efficient search. Specifically, we propose to enhance search in unstructured P2P overlay networks by building a partial index of shared data using a structured P2P network. The index maintains two types of information: the top interests of peers and globally unpopular data, both characterized by data properties. The proposed search protocol, assisted search with partial indexing, makes use of the index to improve search in three ways: first, the index assists peers to find other peers with similar interests and the unstructured search overlay is formed to reflect peer interests. Second, the index also provides search hints for those data difficult to locate by exploring peer interest locality, and these hints can be used for second-chance search. Third, the index helps to locate unpopular data items. Experiments based on a P2P file sharing trace show that the assisted search with a lightweight partial indexing service can significantly improve the success rate in locating data than Gnutella and a hit-rate-based protocol in unstructured P2P systems, while incurring low search latency and overheads.