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Distributed algorithm

About: Distributed algorithm is a research topic. Over the lifetime, 20416 publications have been published within this topic receiving 548109 citations.


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Journal ArticleDOI
TL;DR: This paper presents a new, succinct specification for a view-oriented partitionable group communication service, and shows the utility of the specification by constructing an ordered-broadcast application, using an algorithm that reconciles information derived from different instantiations of the group.
Abstract: Group communication services are becoming accepted as effective building blocks for the construction of fault-tolerant distributed applications. Many specifications for group communication services have been proposed. However, there is still no agreement about what these specifications should say, especially in cases where the services are partitionable, i.e., where communication failures may lead to simultaneous creation of groups with disjoint memberships, such that each group is unware of the existence of any other group. In this paper, we present a new, succinct specification for a view-oriented partitionable group communication service. The service associates each message with a particular view of the group membership. All send and receive events for a message occur within the associated view. The service provides a total order on the messages within each view, and each processor receives a prefix of this order. Our specification separates safety requirements from performance and fault-tolerance requirements. The safety requirements are expressed by an abstract, global state machine. To present the performance and fault-tolerance requirements, we include failure-status input actions in the specification; we then give properties saying that consensus on the view and timely message delivery are guaranteed in an execution provided that the execution stabilizes to a situation in which the failure-status stops changing and corresponds to consistently partioned system. Because consensus is not required in every execution, the specification is not subject to the existing impossibility results for partionable systems. Our specification has a simple implementation, based on the membership algorithm of Christian and Schmuck. We show the utility of the specification by constructing an ordered-broadcast application, using an algorithm (based on algorithms of Amir, Dolev, Keidar, and others) that reconciles information derived from different instantiations of the group. The application manages the view-change activity to build a shared sequence of messages, i.e., the per-view total orders of the group service are combined to give a universal total order. We prove the correctness and analyze the performance and fault-tolerance of the resulting application.

122 citations

Book ChapterDOI
08 Jan 2006
TL;DR: This paper introduces environment abstraction as a tool for the verification of concurrent parameterized systems with unbounded variables and demonstrates the feasibility of the approach by verifying the safety and liveness properties of Lamport's bakery algorithm and Szymanski's mutual exclusion algorithm.
Abstract: Many aspects of computer systems are naturally modeled as parameterized systems which renders their automatic verification difficult. In well-known examples such as cache coherence protocols and mutual exclusion protocols, the unbounded parameter is the number of concurrent processes which run the same distributed algorithm. In this paper, we introduce environment abstraction as a tool for the verification of such concurrent parameterized systems. Environment abstraction enriches predicate abstraction by ideas from counter abstraction; it enables us to reduce concurrent parameterized systems with unbounded variables to precise abstract finite state transition systems which can be verified by a finite state model checker. We demonstrate the feasibility of our approach by verifying the safety and liveness properties of Lamport's bakery algorithm and Szymanski's mutual exclusion algorithm. To the best of our knowledge, this is the first time both safety and liveness properties of the bakery algorithm have been verified at this level of automation.

122 citations

Proceedings ArticleDOI
20 Jun 2011
TL;DR: V-MAN is presented, a fully decentralized algorithm for consolidating VMs in large Cloud datacenters that uses a simple gossip protocol to achieve efficiency, scalability and robustness to failures and can cope with computing nodes being added to or removed from the Cloud.
Abstract: The success of Cloud computing, where computing power is treated as a utility, has resulted in the creation of many large datacenters that are very expensive to build and operate. In particular, the energy bill accounts for a significant fraction of the total operation costs. For this reason a significant attention is being devoted to energy conservation techniques, for example by taking advantage of the built-in power saving features of modern hardware. Cloud computing offers novel opportunities for achieving energy savings: Cloud systems rely on virtualization techniques to allocate computing resources on demand, and modern Virtual Machine (VM) monitors allow live migration of running VMs. Thus, energy conservation can be achieved through server consolidation, moving VM instances away from lightly loaded computing nodes so that they become empty and can be switched to low-power mode. In this paper we present V-MAN, a fully decentralized algorithm for consolidating VMs in large Cloud datacenters. V-MAN can operate on any arbitrary initial allocation of VMs on the Cloud, iteratively producing new allocations that quickly converge towards the one maximizing the number of idle hosts. V-MAN uses a simple gossip protocol to achieve efficiency, scalability and robustness to failures. Simulation experiments indicate that, starting from a random allocation, V-MAN produces an almost-optimal VM placement in just a few rounds; the protocol is intrinsically robust and can cope with computing nodes being added to or removed from the Cloud.

122 citations

Book ChapterDOI
22 Apr 2003
TL;DR: A scalable distributed algorithm that uses local information to efficiently update the global multi-target identity information represented as a doubly stochastic matrix, and can be efficiently mapped to nodes in a wireless ad hoc sensor network.
Abstract: This paper presents a scalable distributed algorithm for computing and maintaining multi-target identity information. The algorithm builds on a novel representational framework, Identity-Mass Flow, to overcome the problem of exponential computational complexity in managing multi-target identity explicitly. The algorithm uses local information to efficiently update the global multi-target identity information represented as a doubly stochastic matrix, and can be efficiently mapped to nodes in a wireless ad hoc sensor network. The paper describes a distributed implementation of the algorithm in sensor networks. Simulation results have validated the Identity-Mass Flow framework and demonstrated the feasibility of the algorithm.

122 citations

Journal ArticleDOI
TL;DR: Multiagent systems have been a major area of research for the last 15 years motivated by tasks that can be executed more rapidly in a collaborative manner or that are nearly impossible to carry out otherwise.
Abstract: Multiagent systems have been a major area of research for the last 15 years. This interest has been motivated by tasks that can be executed more rapidly in a collaborative manner or that are nearly impossible to carry out otherwise. To be effective, the agents need to have the notion of a common goal shared by the entire network (for instance, a desired formation) and individual control laws to realize the goal. The common goal is typically centralized, in the sense that it involves the state of all the agents at the same time. On the other hand, it is often desirable to have individual control laws that are distributed, in the sense that the desired action of an agent depends only on the measurements and states available at the node and at a small number of neighbors. This is an attractive quality because it implies an overall system that is modular and intrinsically more robust to communication delays and node failures.

122 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202381
2022135
2021583
2020759
2019876
2018845