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GraphTheoretic Analysis of Structured PeertoPeer Systems: Routing Distances and Fault Resilience
, 2003
"... This paper examines graphtheoretic properties of existing peertopeer architectures and proposes a new infrastructure based on optimaldiameter de Bruijn graphs. Since generalized de Bruijn graphs possess very short average routing distances and high resilience to node failure, they are well suite ..."
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Cited by 127 (7 self)
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This paper examines graphtheoretic properties of existing peertopeer architectures and proposes a new infrastructure based on optimaldiameter de Bruijn graphs. Since generalized de Bruijn graphs possess very short average routing distances and high resilience to node failure, they are well suited for structured peertopeer networks. Using the example of Chord, CAN, and de Bruijn, we first study routing performance, graph expansion, and clustering properties of each graph. We then examine bisection width, path overlap, and several other properties that affect routing and resilience of peertopeer networks. Having confirmed that de Bruijn graphs offer the best diameter and highest connectivity among the existing peertopeer structures, we offer a very simple incremental building process that preserves optimal properties of de Bruijn graphs under uniform user joins/departures. We call the combined peertopeer architecture
Know thy Neighbor's Neighbor: the Power of Lookahead in Randomized P2P Networks
 In Proceedings of the 36th ACM Symposium on Theory of Computing (STOC
, 2004
"... Several peertopeer networks are based upon randomized graph topologies that permit e#cient greedy routing, e.g., randomized hypercubes, randomized Chord, skipgraphs and constructions based upon smallworld percolation networks. In each of these networks, a node has outdegree #(log n), where n de ..."
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Cited by 102 (5 self)
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Several peertopeer networks are based upon randomized graph topologies that permit e#cient greedy routing, e.g., randomized hypercubes, randomized Chord, skipgraphs and constructions based upon smallworld percolation networks. In each of these networks, a node has outdegree #(log n), where n denotes the total number of nodes, and greedy routing is known to take O(log n) hops on average. We establish lowerbounds for greedy routing for these networks, and analyze NeighborofNeighbor (NoN)greedy routing. The idea behind NoN, as the name suggests, is to take a neighbor's neighbors into account for making better routing decisions.
SETS: Search Enhanced by Topic Segmentation
, 2003
"... We present SETS, an architecture for building topicsegmented networks for efficient search. The key idea is to arrange participants in a topicsegmented topology where most of the links are shortdistance links joining pairs of sites with similar content. The resulting topically focused regions are ..."
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Cited by 85 (4 self)
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We present SETS, an architecture for building topicsegmented networks for efficient search. The key idea is to arrange participants in a topicsegmented topology where most of the links are shortdistance links joining pairs of sites with similar content. The resulting topically focused regions are joined together into a single network by longdistance links. Queries are then matched and routed to only the topically closest regions. We draw on ideas from machine learning and social network theory to build an efficient search network. We discuss a variety of design issues and tradeoffs that an implementor of SETS would face. We show that SETS is ecient in network traffic and query processing load.
Canon in G major: Designing DHTs with hierarchical structure
 In ICDCS
, 2004
"... Distributed Hash Tables have been proposed as flat, nonhierarchical structures, in contrast to most scalable distributed systems of the past. We show how to construct hierarchical DHTs while retaining the homogeneity of load and functionality offered by flat designs. Our generic construction, Canon, ..."
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Cited by 80 (1 self)
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Distributed Hash Tables have been proposed as flat, nonhierarchical structures, in contrast to most scalable distributed systems of the past. We show how to construct hierarchical DHTs while retaining the homogeneity of load and functionality offered by flat designs. Our generic construction, Canon, offers the same routing state v/s routing hops tradeoff provided by standard DHT designs. The advantages of Canon include (but are not limited to) (a) fault isolation, (b) efficient caching and effective bandwidth usage for multicast, (c) adaptation to the underlying physical network, (d) hierarchical storage of content, and (e) hierarchical access control. Canon can be applied to many different proposed DHTs to construct their Canonical versions. We show how four different DHTs—Chord, Symphony, CAN and Kademlia—can be converted into their Canonical versions that we call Crescendo, Cacophony,
Balanced binary trees for id management and load balance in distributed hash tables. In: PODC.
, 2004
"... ..."
Implementing aggregation and broadcast over distributed hash tables
 ACM SIGCOMM Computer Communication Review
, 2005
"... Peertopeer (P2P) networks represent an effective way to share information, since there are no central points of failure or bottleneck. However, the flip side to the distributive nature of P2P networks is that it is not trivial to aggregate and broadcast global information efficiently. We believe t ..."
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Cited by 22 (2 self)
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Peertopeer (P2P) networks represent an effective way to share information, since there are no central points of failure or bottleneck. However, the flip side to the distributive nature of P2P networks is that it is not trivial to aggregate and broadcast global information efficiently. We believe that this aggregation/broadcast functionality is a fundamental service that should be layered over existing Distributed Hash Tables (DHTs), and in this work, we design a novel algorithm for this purpose. Specifically, we build an aggregation/broadcast tree in a bottomup fashion by mapping nodes to their parents in the tree with a parent function. The particular parent function family we propose allows the efficient construction of multiple interiornodedisjoint trees, thus preventing single points of failure in tree structures. In this way, we provide DHTs with an ability to collect and disseminate information efficiently on a global scale. Simulation results demonstrate that our algorithm is efficient and robust.
Decentralized algorithms using both local and random probes for p2p load balancing
 In Seventeenth ACM Symposium on Parallelism in Algorithms and Architectures (SPAA
, 2005
"... We study randomized algorithms for placing a sequence of n nodes on a circle with unit perimeter. Nodes divide the circle into disjoint arcs. We desire that a newlyarrived node (which is oblivious of its index in the sequence) choose its position on the circle by learning the positions of as few ex ..."
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Cited by 20 (0 self)
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We study randomized algorithms for placing a sequence of n nodes on a circle with unit perimeter. Nodes divide the circle into disjoint arcs. We desire that a newlyarrived node (which is oblivious of its index in the sequence) choose its position on the circle by learning the positions of as few existing nodes as possible. At the same time, we desire that that the variation in arclengths be small. To this end, we propose a new algorithm that works as follows: The k th node chooses r random points on the circle, inspects the sizes of v arcs in the vicinity of each random point, and places itself at the midpoint of the largest arc encountered. We show that for any combination of r and v satisfying rv ≥ c log k, where c is a small constant, the ratio of the largest to the smallest arclength is at most eight w.h.p., for an arbitrarily long
Nonuniform random membership management in peertopeer networks
 In Proc. of the IEEE INFOCOM
, 2005
"... Abstract — Existing random membership management algorithms provide each node with a small, uniformly random subset of global participants. However, many applications would benefit more from nonuniform random member subsets. For instance, nonuniform gossip algorithms can provide distancebased prop ..."
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Cited by 17 (2 self)
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Abstract — Existing random membership management algorithms provide each node with a small, uniformly random subset of global participants. However, many applications would benefit more from nonuniform random member subsets. For instance, nonuniform gossip algorithms can provide distancebased propagation bounds and thus information can reach nearby nodes sooner. In another example, Kleinberg shows that networks with random longlinks following distancebased nonuniform distributions exhibit better routing performance than those with uniformly randomized topologies. In this paper, we propose a scalable nonuniform random membership management algorithm, which provides each node with a random membership subset with applicationspecified probability distributions—e.g., with probability inversely proportional to distances. Our algorithm is the first nonuniform random membership management algorithm with proved convergence and bounded convergence time. Moreover, our algorithm does not put specific restrictions on the network topologies and thus have wide applicability. I.
Counting at large: Efficient cardinality estimation in internetscale data networks
 In Proc. IEEE ICDE
, 2006
"... Counting in general, and estimating the cardinality of (multi) sets in particular, is highly desirable for a large variety of applications, representing a foundational block for the efficient deployment and access of emerging internetscale information systems. Examples of such applications range fr ..."
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Cited by 16 (2 self)
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Counting in general, and estimating the cardinality of (multi) sets in particular, is highly desirable for a large variety of applications, representing a foundational block for the efficient deployment and access of emerging internetscale information systems. Examples of such applications range from optimizing query access plans in internetscale databases, to evaluating the significance (rank/score) of various data items in information retrieval applications. The key constraints that any acceptable solution must satisfy are: (i) efficiency: the number of nodes that need be contacted for counting purposes must be small in order to enjoy small latency and bandwidth requirements; (ii) scalability, seemingly contradicting the efficiency goal: arbitrarily large numbers of nodes nay need to add elements to a (multi) set, which dictates the need for a highly distributed solution, avoiding serverbased scalability, bottleneck, and availability problems; (iii) access and storage load balancing: counting and related overhead chores should be distributed fairly to the nodes of the network; (iv) accuracy: tunable, robust (in the presence of dynamics and failures) and highly accurate cardinality estimation; (v) simplicity and ease of integration: special, solutionspecific indexing structures should be avoided. In this paper, first we contribute a highlydistributed, scalable, efficient, and accurate (multi) set cardinality estimator. Subsequently, we show how to use our solution to build and maintain histograms, which have been a basic building block for query optimization for centralized databases, facilitating their porting into the realm of internetscale data networks. 1
Peer to peer size estimation in large and dynamic networks: A comparative study
"... As the size of distributed systems keeps growing, the peer to peer communication paradigm has been identified as the key to scalability. Peer to peer overlay networks are characterized by their selforganizing capabilities, resilience to failure and fully decentralized control. In a peer to peer ove ..."
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Cited by 16 (1 self)
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As the size of distributed systems keeps growing, the peer to peer communication paradigm has been identified as the key to scalability. Peer to peer overlay networks are characterized by their selforganizing capabilities, resilience to failure and fully decentralized control. In a peer to peer overlay, no entity has a global knowledge of the system. As much as this property is essential to ensure the scalability, monitoring the system under such circumstances is a complex task. Yet, estimating the size of the system is a core functionality for many distributed applications to parameter setting or monitoring purposes. In this paper, we propose a comparative study between three algorithms that estimate in a fully decentralized way the size of a peer to peer overlay. Candidate approaches are generally applicable irrespective of the underlying structure of the peer to peer overlay. The paper reports the head to head comparison of estimation system size algorithms. The simulations have been conducted using the same simulation framework and inputs and highlight the differences in cost and accuracy of the estimation between the algorithms both in static and dynamic settings. I.