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19
Lightweight probabilistic broadcast
 ACM Transaction on Computer Systems
, 2003
"... The growing interest in peertopeer applications has underlined the importance of scalability in modern distributed systems. Not surprisingly, much research effort has been invested in gossipbased broadcast protocols. These trade the traditional strong reliability guarantees against very good “sca ..."
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Cited by 241 (33 self)
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The growing interest in peertopeer applications has underlined the importance of scalability in modern distributed systems. Not surprisingly, much research effort has been invested in gossipbased broadcast protocols. These trade the traditional strong reliability guarantees against very good “scalability” properties. Scalability is in that context usually expressed in terms of throughput and delivery latency, but there is only little work on how to reduce the overhead of membership management at large scale. This paper presents Lightweight Probabilistic Broadcast (lpbcast), a novel gossipbased broadcast algorithm which preserves the inherent throughput scalability of traditional gossipbased algorithms and adds a notion of membership management scalability: every process only knows a random subset of fixed size of the processes in the system. We formally analyze our broadcast algorithm in terms of scalability with respect to the size of individual views, and compare the analytical results both with simulations and concrete measurements.
Randomized Gossip Algorithms
 IEEE TRANSACTIONS ON INFORMATION THEORY
, 2006
"... Motivated by applications to sensor, peertopeer, and ad hoc networks, we study distributed algorithms, also known as gossip algorithms, for exchanging information and for computing in an arbitrarily connected network of nodes. The topology of such networks changes continuously as new nodes join a ..."
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Cited by 208 (5 self)
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Motivated by applications to sensor, peertopeer, and ad hoc networks, we study distributed algorithms, also known as gossip algorithms, for exchanging information and for computing in an arbitrarily connected network of nodes. The topology of such networks changes continuously as new nodes join and old nodes leave the network. Algorithms for such networks need to be robust against changes in topology. Additionally, nodes in sensor networks operate under limited computational, communication, and energy resources. These constraints have motivated the design of “gossip ” algorithms: schemes which distribute the computational burden and in which a node communicates with a randomly chosen neighbor. We analyze the averaging problem under the gossip constraint for an arbitrary network graph, and find that the averaging time of a gossip algorithm depends on the second largest eigenvalue of a doubly stochastic matrix characterizing the algorithm. Designing the fastest gossip algorithm corresponds to minimizing this eigenvalue, which is a semidefinite program (SDP). In general, SDPs cannot be solved in a distributed fashion; however, exploiting problem structure, we propose a distributed subgradient method that solves the optimization problem over the network. The relation of averaging time to the second largest eigenvalue naturally relates it to the mixing time of a random walk with transition probabilities derived from the gossip algorithm. We use this connection to study the performance and scaling of gossip algorithms on two popular networks: Wireless Sensor Networks, which are modeled as Geometric Random Graphs, and the Internet graph under the socalled Preferential Connectivity (PC) model.
Peertopeer membership management for gossipbased protocols
 IEEE TRANSACTIONS ON COMPUTERS
, 2003
"... Gossipbased protocols for group communication have attractive scalability and reliability properties. The probabilistic gossip schemes studied so far typically assume that each group member has full knowledge of the global membership and chooses gossip targets uniformly at random. The requirement ..."
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Cited by 167 (21 self)
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Gossipbased protocols for group communication have attractive scalability and reliability properties. The probabilistic gossip schemes studied so far typically assume that each group member has full knowledge of the global membership and chooses gossip targets uniformly at random. The requirement of global knowledge impairs their applicability to very largescale groups. In this paper, we present SCAMP (Scalable Membership protocol), a novel peertopeer membership protocol which operates in a fully decentralized manner and provides each member with a partial view of the group membership. Our protocol is selforganizing in the sense that the size of partial views naturally converges to the value required to support a gossip algorithm reliably. This value is a function of the group size, but is achieved without any node knowing the group size. We propose additional mechanisms to achieve balanced view sizes even with highly unbalanced subscription patterns. We present the design, theoretical analysis, and a detailed evaluation of the basic protocol and its refinements. Simulation results show that the reliability guarantees provided by SCAMP are comparable to previous schemes based on global knowledge. The scale of the experiments attests to the scalability of the protocol.
Gossip algorithms: Design, analysis and applications. 2004. Submitted, available at www.stanford.edu/~devavrat/infocom05.ps
"... Ahtruct Motivated by applications to sensor, peertopeer and ad hoc networks, we study distributed asynchronous algorithms, also known as gossip algorithms, for computation and information exchange in an arbitrarily connected network of nodes. Nodes in such networks operate under limited computatio ..."
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Cited by 158 (14 self)
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Ahtruct Motivated by applications to sensor, peertopeer and ad hoc networks, we study distributed asynchronous algorithms, also known as gossip algorithms, for computation and information exchange in an arbitrarily connected network of nodes. Nodes in such networks operate under limited computational, communication and energy resources. These constraints naturally give rise to "gossip " algorithms: schemes which distribute the computational burden and in which a node communicates with a randomly chosen neighbor. We analyze the averaging problem under the gossip constraint for arbitrary network, and find that the averaging time of a gossip algorithm depends on the second largest eigenvalue of a doubly stochastic mairix characterizing the algorithm. Using recent results of Boyd, Diaconis and Xiao
Spatial gossip and resource location protocols
, 2001
"... The dynamic behavior of a network in which information is changing continuously over time requires robust and efficient mechanisms for keeping nodes updated about new information. Gossip protocols are mechanisms for this task in which nodes communicate with one another according to some underlying d ..."
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Cited by 141 (7 self)
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The dynamic behavior of a network in which information is changing continuously over time requires robust and efficient mechanisms for keeping nodes updated about new information. Gossip protocols are mechanisms for this task in which nodes communicate with one another according to some underlying deterministic or randomized algorithm, exchanging information in each communication step. In a variety of contexts, the use of randomization to propagate information has been found to provide better reliability and scalability than more regimented deterministic approaches. In many settings, such as a cluster of distributed computing hosts, new information is generated at individual nodes, and is most “interesting ” to nodes that are nearby. Thus, we propose distancebased propagation bounds as a performance measure for gossip mechanisms: a node at distance d from the origin of a new piece of information should be able to learn about this information with a delay that grows slowly with d, and is independent of the size of the network. For nodes arranged with uniform density in Euclidean space, we present natural gossip mechanisms, called spatial gossip, that satisfy such a guarantee: new information is spread to
Estimating aggregates on a peertopeer network
, 2003
"... As PeertoPeer (P2P) networks become popular, there is an emerging need to collect a variety of statistical summary information about the participating nodes. The P2P networks of today lack mechanisms to compute even such basic aggregates as MIN, MAX, SUM, COUNT or AVG. In this paper, we define and ..."
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Cited by 65 (4 self)
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As PeertoPeer (P2P) networks become popular, there is an emerging need to collect a variety of statistical summary information about the participating nodes. The P2P networks of today lack mechanisms to compute even such basic aggregates as MIN, MAX, SUM, COUNT or AVG. In this paper, we define and study the NODEAGGREGATION problem that is concerned with aggregating data stored at nodes in the network. We present generic schemes that can be used to compute any of the basic aggregation functions accurately and robustly. Our schemes can be used as building blocks for tools to collect statistics on network topology, user behavior and other node characteristics. This is a STUDENT paper intended as a REGULAR presentation. I.
SmartTag Based Data Dissemination
, 2002
"... Monitoring wide, hostile areas requires disseminating data between fixed, disconnected clusters of sensor nodes. It is not always possible to install longrange radios in order to cover the whole area. We propose to leverage the movement of mobile individuals, equipped with smarttags, to disseminat ..."
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Cited by 56 (5 self)
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Monitoring wide, hostile areas requires disseminating data between fixed, disconnected clusters of sensor nodes. It is not always possible to install longrange radios in order to cover the whole area. We propose to leverage the movement of mobile individuals, equipped with smarttags, to disseminate data across disconnected static nodes spread across a wide area. Static nodes and mobile smarttags exchange data when they are in the vicinity of each other; smarttags disseminate data as they move around. In this paper, we propose an algorithm for update propagation and a model for smarttag based data dissemination. We use simulation to study the characteristics of the model we propose. Finally, we present an implementation based on bluetooth smarttags.
Protocols and impossibility results for gossipbased communication mechanisms
, 2002
"... In recent years, gossipbased algorithms have gained prominence as a methodology for designing robust and scalable communication schemes in large distributed systems. The premise underlying distributed gossip is very simple: in each time step, each node v in the system selects some other node w as a ..."
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Cited by 55 (3 self)
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In recent years, gossipbased algorithms have gained prominence as a methodology for designing robust and scalable communication schemes in large distributed systems. The premise underlying distributed gossip is very simple: in each time step, each node v in the system selects some other node w as a communication partner — generally by a simple randomized rule — and exchanges information with w; over a period of time, information spreads through the system in an “epidemic fashion”. A fundamental issue which is not well understood is the following: how does the underlying lowlevel gossip mechanism — the means by which communication partners are chosen — affect one’s ability to design efficient highlevel gossipbased protocols? We establish one of the first concrete results addressing this question, by showing a fundamental limitation on the power of the commonly used uniform gossip mechanism for solving nearestresource location problems. In contrast, very efficient protocols for this problem can be designed using a nonuniform spatial gossip mechanism, as established in earlier work with Alan Demers. We go on to consider the design of protocols for more complex problems, providing an efficient distributed gossipbased protocol for a set of nodes in Euclidean space to construct an approximate minimum spanning tree. Here too, we establish a contrasting limitation on the power of uniform gossip for solving this problem. Finally, we investigate gossipbased packet routing as a primitive that underpins the communication patterns in many protocols, and as a way to understand the capabilities of different gossip mechanisms at a general level.
Gossip and Mixing Times of Random Walks on Random Graphs
, 2004
"... Motivated by applications to sensor and ad hoc networks, we study distributed algorithms for passing information and for computing averages in an arbitrarily connected network of nodes. Our work draws upon and contributes to a growing body of literature in three areas: (i) Distributed averaging algo ..."
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Cited by 12 (0 self)
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Motivated by applications to sensor and ad hoc networks, we study distributed algorithms for passing information and for computing averages in an arbitrarily connected network of nodes. Our work draws upon and contributes to a growing body of literature in three areas: (i) Distributed averaging algorithms, as formulated in Kempe, Dobra and Gehrke (2003), (ii) geometric random graph models for large networks of sensors, as put forth in Gupta and Kumar (2000), and (iii) the fastest mixing Markov chain on a graph, as studied recently in Boyd, Diaconis and Xiao (2003). For distributed averaging...
A Unified Framework for Resource Discovery and QoSAware Provider Selection in Ad Hoc Networks
 ACM Mobile Computing and Communications Review
, 2002
"... With the rising popularity of networkbased applications and the potential use of mobile ad hoc networks in civilian life, an efficient resource discovery service is needed in such networks for quickly locating resource providers. In addition, to improve user experience, QoS awareness is also cru ..."
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Cited by 11 (1 self)
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With the rising popularity of networkbased applications and the potential use of mobile ad hoc networks in civilian life, an efficient resource discovery service is needed in such networks for quickly locating resource providers. In addition, to improve user experience, QoS awareness is also crucial. In this paper, we identify the challenges when basic resource discovery techniques for the Internet are used in mobile ad hoc networks. We then propose a framework that provides a unified solution to the discovery of resources and QoSaware selection of resource providers. The key entities of this framework are a set of selforganized discovery agents. These agents manage the directory information of resources using hash indexing. They also dynamically partition the network into domains and collect intra and interdomain QoS information to select appropriate providers.