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69
FaultContaining SelfStabilizing Algorithms
 In PODC96 Proceedings of the Fifteenth Annual ACM Symposium on Principles of Distributed Computing
, 1996
"... . Selfstabilization provides a nonmasking approach to fault tolerance. Given this fact, one would hope that in a selfstabilizing system, the amount of disruption caused by a fault is proportional to the severity of the fault. However, this is not true for many selfstabilizing systems. Our paper ..."
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Cited by 78 (8 self)
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. Selfstabilization provides a nonmasking approach to fault tolerance. Given this fact, one would hope that in a selfstabilizing system, the amount of disruption caused by a fault is proportional to the severity of the fault. However, this is not true for many selfstabilizing systems. Our paper addresses this weakness of distributed selfstabilizing systems by introducing the notion of fault containment. Informally, a faultcontaining selfstabilizing algorithm is one that contains the effects of limited transient faults while retaining the property of selfstabilization. The paper begins with a formal framework for specifying and evaluating faultcontaining selfstabilizing protocols. Then, it is shown that selfstabilization and fault containment are goals that can conflict. For example, it is shown that imposing a O(1) bound on the worst case recovery time from a 1faulty state necessitates added overhead for stabilization: for some tasks, the O(1) recovery time implies stabiliz...
gs3: Scalable selfconfiguration and selfhealing in wireless networks
 21st ACM SIGACTSIGOPS Symposium on Principles of Distributed Computing
, 2002
"... ABSTRACT We present GS 3 , a distributed, scalable, selfconfiguration and selfhealing algorithm for multihop wireless networks. The algorithm enables network nodes in a 2D plane to configure themselves into a cellular hexagonal structure such that cells have tightly bounded geographic radius and ..."
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Cited by 59 (4 self)
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ABSTRACT We present GS 3 , a distributed, scalable, selfconfiguration and selfhealing algorithm for multihop wireless networks. The algorithm enables network nodes in a 2D plane to configure themselves into a cellular hexagonal structure such that cells have tightly bounded geographic radius and low overlap between neighboring cells. The structure is selfhealing under various perturbations, such as node joins, leaves, deaths, movements, and state corruptions. For instance, it slides as a whole if nodes in many cells die at the same rate. Moreover, its configuration and healing are scalable in three respects: first, local knowledge enables each node to maintain only limited information with respect to a constant number of nearby nodes; second, local healing guarantees that all perturbations are contained within a tightly bounded region with respect to the perturbed area and dealt with in a oneway message diffusion time across the region; third, only local coordination is needed in both configuration and selfhealing.
TimeAdaptive Self Stabilization
, 1997
"... We study the scenario where a transient fault hit f of the n nodes of a distributed system by corrupting their state. We consider the basic persistent bit problem, where the system is required to maintain a 0/1 value in the face of transient failures by means of replication. We give an algorithm ..."
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Cited by 41 (6 self)
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We study the scenario where a transient fault hit f of the n nodes of a distributed system by corrupting their state. We consider the basic persistent bit problem, where the system is required to maintain a 0/1 value in the face of transient failures by means of replication. We give an algorithm to recover the value quickly: the value of the bit is recovered at all nodes in O(f) time units for an unknown f ! n=2. Moreover, complete state quiescence occurs in O(diam) time units, where diam denotes the actual diameter of the network. This means that the value persists indefinitely so long as any f ! n=2 faults are followed by \Omega\Gamma diam) faultfree time units. We prove matching lower bounds on both the output stabilization time and the state quiescence time. Using our persistent bit algorithm, we present a general transformer which takes a distributed nonreactive nonstabilizing protocol P , and produces a selfstabilizing protocol P 0 which solves the problem P solv...
Local Majority Voting, Small Coalitions and Controlling Monopolies in Graphs: A Review
 IN PROC. OF 3RD COLLOQUIUM ON STRUCTURAL INFORMATION AND COMMUNICATION COMPLEXITY
, 1996
"... This paper provides an overview of recent developments concerning the process of local majority voting in graphs, and its basic properties, from graph theoretic and algorithmic standpoints. ..."
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Cited by 40 (1 self)
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This paper provides an overview of recent developments concerning the process of local majority voting in graphs, and its basic properties, from graph theoretic and algorithmic standpoints.
Local Stabilizer
 In Proceedings of the 5th Israel Symposium on Theory of Computing and Systems
, 1997
"... A local stabilizer protocol that takes any online or offline distributed algorithm and converts it into a synchronous selfstabilizing algorithm with local monitoring and repairing properties is presented. Whenever the selfstabilizing version enters an inconsistent state, the inconsistency is ..."
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Cited by 36 (1 self)
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A local stabilizer protocol that takes any online or offline distributed algorithm and converts it into a synchronous selfstabilizing algorithm with local monitoring and repairing properties is presented. Whenever the selfstabilizing version enters an inconsistent state, the inconsistency is detected, in O(1) time, and the system state is repaired in a local manner. The expected computation time that is lost during the repair process is proportional to the largest diameter of a faulty region. An extended abstract of this paper appeared in the Proc. of the 5th Israeli Symposium on Theory of Computing and Systems, June 1997 and a brief announcement in Proc. of the 16th Annual ACM Symp. on Principles of Distributed Computing, August 1997. y Computer Science Department, TelAviv University, TelAviv, 69978, Israel. Email: afek@math.tau.ac.il. z Department of Mathematics and Computer Science, BenGurion University, BeerSheva, 84105, Israel. Partially supported by the Israeli m...
Local Computations on Static and Dynamic Graphs
, 1995
"... The purpose of this paper is a study of computation that can be done locally in a dynamic distributed network. By locally we mean within time (or distance) independent of the size of the network and by dynamic we mean that the underlying graph is not stable and links continuously fail and comeup. O ..."
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Cited by 30 (2 self)
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The purpose of this paper is a study of computation that can be done locally in a dynamic distributed network. By locally we mean within time (or distance) independent of the size of the network and by dynamic we mean that the underlying graph is not stable and links continuously fail and comeup. One of the main contributions of this work is a definition of robustness, which captures the nature of an algorithm performing well in such an environment. The second
A local algorithm for ad hoc majority voting via charge fusion
 In Proceedings of the 18th annual conference on distributed computing
, 2004
"... Abstract — We present a local distributed algorithm for a general Majority Voting problem: different and timevariable voting powers and vote splits, arbitrary and dynamic interconnection topologies and link delays, and any fixed majority threshold. The algorithm combines a novel, efficient anytime s ..."
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Cited by 24 (12 self)
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Abstract — We present a local distributed algorithm for a general Majority Voting problem: different and timevariable voting powers and vote splits, arbitrary and dynamic interconnection topologies and link delays, and any fixed majority threshold. The algorithm combines a novel, efficient anytime spanning forest algorithm, which may also have applications elsewhere, with a “charge fusion ” algorithm that roots trees at nodes with excess “charge ” (derived from a node’s voting power and vote split), and subsequently transfers charges along tree links to oppositely charged roots for fusion. At any instant, every node has an ad hoc belief regarding the outcome. Once all changes have ceased, the correct majority decision is reached by all nodes, within a time that in many cases is independent of the graph size. The algorithm’s correctness and salient properties are proved, and experiments with up to a million nodes provide further validation and actual numbers. To our knowledge, this is the first localitysensitive solution to the Majority Vote problem for arbitrary, dynamically changing communication graphs. A. Background I.
Veracity radius  capturing the locality of distributed computations
 ACM PODC
, 2006
"... This paper focuses on local computations of distributed aggregation problems on fixed graphs. We define a new metric on problem instances, Veracity Radius (VR), which captures the inherent possibility to compute them locally. We prove that VR yields a tight lower bound on outputstabilization time, ..."
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Cited by 23 (8 self)
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This paper focuses on local computations of distributed aggregation problems on fixed graphs. We define a new metric on problem instances, Veracity Radius (VR), which captures the inherent possibility to compute them locally. We prove that VR yields a tight lower bound on outputstabilization time, i.e., the time until all nodes fix their outputs, as well as a lower bound on quiescence time. We present an efficient aggregation algorithm, ILEAG, which reaches both output stabilization and quiescence within a time that is proportional to the VR of the problem instance, and is also efficient in terms of pernode communication and memory. We empirically show that the VR metric also effectively captures the performance of previously suggested efficient aggregation protocols, and that ILEAG significantly outperforms these protocols in several respects.
Stabilizing TimeAdaptive Protocols
, 1998
"... We study the scenario where a transient batch of faults hit a minority of the nodes in a distributed system by corrupting their state. We concentrate on the basic persistent bit problem, where the system is required to maintain a 0/1 value in the face of transient failures by means of replication ..."
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Cited by 21 (4 self)
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We study the scenario where a transient batch of faults hit a minority of the nodes in a distributed system by corrupting their state. We concentrate on the basic persistent bit problem, where the system is required to maintain a 0/1 value in the face of transient failures by means of replication. We give an algorithm to stabilize the value to a correct state quickly; that is, denoting the unknown number of faulty nodes by f , our algorithm recovers the value of the bit at all nodes in O(f) time units for any f ! n=2, where n is the number of all nodes. Moreover,
A Generic Local Algorithm for Mining Data Streams in Large Distributed Systems
, 2006
"... In a large network of computers or wireless sensors, each of the components (henceforth, peers) has some data about the global state of the system. Much of the system’s functionality such as message routing, information retrieval and load sharing relies on modeling the global state. We refer to the ..."
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Cited by 20 (8 self)
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In a large network of computers or wireless sensors, each of the components (henceforth, peers) has some data about the global state of the system. Much of the system’s functionality such as message routing, information retrieval and load sharing relies on modeling the global state. We refer to the outcome of the function (e.g., the load experienced by each peer) as the model of the system. Since the state of the system is constantly changing, it is necessary to keep the models uptodate. Computing global data mining models e.g. decision trees, kmeans clustering in large distributed systems may be very costly due to the scale of the system and due to communication cost, which may be high. The cost further increases in a dynamic scenario when the data changes rapidly. In this paper we describe a two step approach for dealing with these costs. First, we describe a highly efficient local algorithm which can be used to monitor a wide class of data mining models. Then, we use this algorithm as a feedback loop for the monitoring of complex functions of the data such as its kmeans clustering. The theoretical claims are corroborated with a thorough experimental analysis.