Hostname: page-component-6b989bf9dc-mbg9n Total loading time: 0 Render date: 2024-04-14T22:59:02.829Z Has data issue: false hasContentIssue false

Randomized Rumour Spreading: The Effect of the Network Topology

Published online by Cambridge University Press:  06 May 2014

KONSTANTINOS PANAGIOTOU
Affiliation:
Mathematisches Institut, Universität München, Theresienstr. 39, 80333 München, Germany (e-mail: kpanagio@math.lmu.de)
XAVIER PÉREZ-GIMÉNEZ
Affiliation:
Max Planck Institute for Informatics, Campus E1.4, 66123 Saarbrücken, Germany (e-mail: xperez@mpi-inf.mpg.de)
THOMAS SAUERWALD
Affiliation:
Computer Laboratory, University of Cambridge, 15 JJ Thomson Avenue, Cambridge CB3 0FD, UK (e-mail: thomas.sauerwald@cl.cam.ac.uk)
HE SUN
Affiliation:
Cluster of Excellence “Multimodal Computing and Interaction”, Computer Science, Saarland University, 66123 Saarbrücken, Germany (e-mail: hsun@mpi-inf.mpg.de)

Abstract

We consider the popular and well-studied push model, which is used to spread information in a given network with n vertices. Initially, some vertex owns a rumour and passes it to one of its neighbours, which is chosen randomly. In each of the succeeding rounds, every vertex that knows the rumour informs a random neighbour. It has been shown on various network topologies that this algorithm succeeds in spreading the rumour within O(log n) rounds. However, many studies are quite coarse and involve huge constants that do not allow for a direct comparison between different network topologies. In this paper, we analyse the push model on several important families of graphs, and obtain tight runtime estimates. We first show that, for any almost-regular graph on n vertices with small spectral expansion, rumour spreading completes after log2n + log n+o(log n) rounds with high probability. This is the first result that exhibits a general graph class for which rumour spreading is essentially as fast as on complete graphs. Moreover, for the random graph G(n,p) with p=c log n/n, where c > 1, we determine the runtime of rumour spreading to be log2n + γ (c)log n with high probability, where γ(c) = clog(c/(c−1)). In particular, this shows that the assumption of almost regularity in our first result is necessary. Finally, for a hypercube on n=2d vertices, the runtime is with high probability at least (1+β) ⋅ (log2n + log n), where β > 0. This reveals that the push model on hypercubes is slower than on complete graphs, and thus shows that the assumption of small spectral expansion in our first result is also necessary. In addition, our results combined with the upper bound of O(log n) for the hypercube (see [11]) imply that the push model is faster on hypercubes than on a random graph G(n, clog n/n), where c is sufficiently close to 1.

Type
Paper
Copyright
Copyright © Cambridge University Press 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1]Alon, N. and Chung, F. R. K. (1988) Explicit construction of linear sized tolerant networks. Discrete Math. 72 1519.Google Scholar
[2]Alon, N. and Spencer, J. (2008) The Probabilistic Method, third edition, Wiley-Interscience Series in Discrete Mathematics and Optimization, Wiley.CrossRefGoogle Scholar
[3]Boyd, S., Ghosh, A., Prabhakar, B. and Shah, D. (2006) Randomized gossip algorithms. IEEE Trans. Inform. Theory 52 25082530.CrossRefGoogle Scholar
[4]Broder, A. Z., Frieze, A. M., Suen, S. and Upfal, E. (1998) Optimal construction of edge-disjoint paths in random graphs. SIAM J. Comput. 28 541573.CrossRefGoogle Scholar
[5]Chierichetti, F., Lattanzi, S. and Panconesi, A. (2010) Almost tight bounds for rumour spreading with conductance. In 42nd Annual ACM Symposium on Theory of Computing: STOC'10, pp. 399–408.CrossRefGoogle Scholar
[6]Cooper, C. and Frieze, A. M. (2007) The cover time of sparse random graphs. Random Struct. Alg. 30 116.CrossRefGoogle Scholar
[7]Doerr, B., Friedrich, T. and Sauerwald, T. (2008) Quasirandom rumor spreading. In 19th Annual ACM-SIAM Symposium on Discrete Algorithms: SODA'08, pp. 773–781. arXiv.1012.5351Google Scholar
[8]Dubhashi, D. and Panconesi, A. (2009) Concentration of Measure for the Analysis of Randomized Algorithms, Cambridge University Press.Google Scholar
[9]Elsässer, R. and Sauerwald, T. (2009) On the runtime and robustness of randomized broadcasting. Theoret. Comput. Sci. 410 34143427.Google Scholar
[10]Elsässer, R. and Sauerwald, T. (2009) Cover time and broadcast time. In 26th International Symposium on Theoretical Aspects of Computer Science: STACS'09, pp. 373–384.Google Scholar
[11]Feige, U., Peleg, D., Raghavan, P. and Upfal, E. (1990) Randomized broadcast in networks. Random Struct. Alg. 1 447460.Google Scholar
[12]Fountoulakis, N. and Panagiotou, K. (2010) Rumor spreading on random regular graphs and expanders. In 14th International Workshop on Randomization and Computation: RANDOM'10, pp. 560–573.CrossRefGoogle Scholar
[13]Fountoulakis, N., Huber, A. and Panagiotou, K. (2010) Reliable broadcasting in random networks and the effect of density. In 29th IEEE Conference on Computer Communications: INFOCOM'10, pp. 2552–2560.Google Scholar
[14]Friedrich, T., Gairing, M. and Sauerwald, T. (2012) Quasirandom load balancing. SIAM J. Comput. 41 747771.Google Scholar
[15]Frieze, A. and Grimmett, G. (1985) The shortest-path problem for graphs with random arc-lengths. Discrete Appl. Math. 10 5777.Google Scholar
[16]Füredi, Z. and Kómlos, J. (1981) The eigenvalues of random symmetric matrices. Combinatorica 3 233241.Google Scholar
[17]Giakkoupis, G. (2011) Tight upper bounds for rumor spreading in graphs of a given conductance. In 28th International Symposium on Theoretical Aspects of Computer Science: STACS'11, pp. 57–68.Google Scholar
[18]Giakkoupis, G. and Sauerwald, T. (2012) Rumor spreading and vertex expansion. In 23rd Annual ACM-SIAM Symposium on Discrete Algorithms: SODA'12,, pp. 1623–1641.Google Scholar
[19]Hoory, S., Linial, N. and Wigderson, A. (2006) Expander graphs and their applications. Bull. Amer. Math. Soc. 43 439561.Google Scholar
[20]Janson, S., Łuczak, T. and Ruciński, A. (2000) Random Graphs, Wiley-Interscience Series in Discrete Mathematics and Optimization, Wiley.Google Scholar
[21]Karp, R., Schindelhauer, C., Shenker, S. and Vöcking, B. (2000) Randomized rumor spreading. In 41st Annual IEEE Symposium on Foundations of Computer Science: FOCS'00, pp. 565–574.Google Scholar
[22]Krivelevich, M. and Sudakov, B. (2006) Pseudo-random graphs. In More Sets, Graphs and Numbers, Vol. 15 of Bolyai Society Mathematical Studies, Springer, pp. 199262.Google Scholar
[23]McDiarmid, C. (1989) On the method of bounded differences. In Surveys in Combinatorics, Vol. 141 of London Mathematical Society Lecture Note Series, Cambridge University Press, pp. 148188.Google Scholar
[24]Meyer, C. D. (2000) Matrix Analysis and Applied Linear Algebra, SIAM. http://www.matrixanalysis.com/DownloadChapters.htmlGoogle Scholar
[25]Mitzenmacher, M. and Upfal, E. (2005) Probability and Computing: Randomized Algorithms and Probabilistic Analysis, Cambridge University Press.Google Scholar
[26]Mosk-Aoyama, D. and Shah, D. (2008) Fast distributed algorithms for computing separable functions. IEEE Trans. Inform. Theory 54 29973007.Google Scholar
[27]Vu, V. H. (2007) Spectral norm of random matrices. Combinatorica 27 721736.Google Scholar