Global computation in a poorly connected world: fast rumor spreading with no dependence on conductance

Original manuscript April 14, 2011

Bibliographic Details
Main Authors: Censor-Hillel, Keren (Contributor), Haeupler, Bernhard (Contributor), Maymounkov, Petar Borissov (Contributor), Kelner, Jonathan Adam (Contributor)
Other Authors: Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory (Contributor), Massachusetts Institute of Technology. Department of Mathematics (Contributor)
Format: Article
Language:English
Published: Association for Computing Machinery (ACM), 2013-09-11T15:18:54Z.
Subjects:
Online Access:Get fulltext
LEADER 03392 am a22002893u 4500
001 80389
042 |a dc 
100 1 0 |a Censor-Hillel, Keren  |e author 
100 1 0 |a Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory  |e contributor 
100 1 0 |a Massachusetts Institute of Technology. Department of Mathematics  |e contributor 
100 1 0 |a Censor-Hillel, Keren  |e contributor 
100 1 0 |a Haeupler, Bernhard  |e contributor 
100 1 0 |a Kelner, Jonathan Adam  |e contributor 
100 1 0 |a Maymounkov, Petar Borissov  |e contributor 
700 1 0 |a Haeupler, Bernhard  |e author 
700 1 0 |a Maymounkov, Petar Borissov  |e author 
700 1 0 |a Kelner, Jonathan Adam  |e author 
245 0 0 |a Global computation in a poorly connected world: fast rumor spreading with no dependence on conductance 
260 |b Association for Computing Machinery (ACM),   |c 2013-09-11T15:18:54Z. 
856 |z Get fulltext  |u http://hdl.handle.net/1721.1/80389 
520 |a Original manuscript April 14, 2011 
520 |a In this paper, we study the question of how efficiently a collection of interconnected nodes can perform a global computation in the GOSSIP model of communication. In this model, nodes do not know the global topology of the network, and they may only initiate contact with a single neighbor in each round. This model contrasts with the much less restrictive LOCAL model, where a node may simultaneously communicate with all of its neighbors in a single round. A basic question in this setting is how many rounds of communication are required for the information dissemination problem, in which each node has some piece of information and is required to collect all others. In the LOCAL model, this is quite simple: each node broadcasts all of its information in each round, and the number of rounds required will be equal to the diameter of the underlying communication graph. In the GOSSIP model, each node must independently choose a single neighbor to contact, and the lack of global information makes it difficult to make any sort of principled choice. As such, researchers have focused on the uniform gossip algorithm, in which each node independently selects a neighbor uniformly at random. When the graph is well-connected, this works quite well. In a string of beautiful papers, researchers proved a sequence of successively stronger bounds on the number of rounds required in terms of the conductance φ and graph size n, culminating in a bound of O(φ[superscript -1] log n). In this paper, we show that a fairly simple modification of the protocol gives an algorithm that solves the information dissemination problem in at most O(D + polylog (n)) rounds in a network of diameter D, with no dependence on the conductance. This is at most an additive polylogarithmic factor from the trivial lower bound of D, which applies even in the LOCAL model. In fact, we prove that something stronger is true: any algorithm that requires T rounds in the LOCAL model can be simulated in O(T + polylog(n)) rounds in the GOSSIP model. We thus prove that these two models of distributed computation are essentially equivalent. 
520 |a Simons Foundation (Postdoctoral Fellows Program) 
520 |a National Science Foundation (U.S.) (Grant CCF-0843915) 
546 |a en_US 
655 7 |a Article 
773 |t Proceedings of the 44th symposium on Theory of Computing (STOC '12)