License: Creative Commons Attribution 3.0 Unported license (CC BY 3.0)
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.ICALP.2016.137
URN: urn:nbn:de:0030-drops-62812
URL: http://dagstuhl.sunsite.rwth-aachen.de/volltexte/2016/6281/
Charron-Bost, Bernadette ;
Függer, Matthias ;
Nowak, Thomas
Fast, Robust, Quantizable Approximate Consensus
Abstract
We introduce a new class of distributed algorithms for the approximate consensus problem in dynamic rooted networks, which we call amortized averaging algorithms. They are deduced from ordinary averaging algorithms by adding a value-gathering phase before each value update. This results in a drastic drop in decision times, from being exponential in the number n of processes to being polynomial under the assumption that each process knows n. In particular, the amortized midpoint algorithm is the first algorithm that achieves a linear decision time in dynamic rooted networks with an optimal contraction rate of 1/2 at each update step.
We then show robustness of the amortized midpoint algorithm under violation of network assumptions: it gracefully degrades if communication graphs from time to time are non rooted, or under a wrong estimate of the number of processes. Finally, we prove that the amortized midpoint algorithm behaves well if processes can store and send only quantized values, rendering it well-suited for the design of dynamic networked systems. As a corollary we obtain that the 2-set consensus problem is solvable in linear time in any dynamic rooted network model.
BibTeX - Entry
@InProceedings{charronbost_et_al:LIPIcs:2016:6281,
author = {Bernadette Charron-Bost and Matthias F{\"u}gger and Thomas Nowak},
title = {{Fast, Robust, Quantizable Approximate Consensus}},
booktitle = {43rd International Colloquium on Automata, Languages, and Programming (ICALP 2016)},
pages = {137:1--137:14},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-013-2},
ISSN = {1868-8969},
year = {2016},
volume = {55},
editor = {Ioannis Chatzigiannakis and Michael Mitzenmacher and Yuval Rabani and Davide Sangiorgi},
publisher = {Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik},
address = {Dagstuhl, Germany},
URL = {http://drops.dagstuhl.de/opus/volltexte/2016/6281},
URN = {urn:nbn:de:0030-drops-62812},
doi = {10.4230/LIPIcs.ICALP.2016.137},
annote = {Keywords: approximate consensus, dynamic networks, averaging algorithms}
}
Keywords: |
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approximate consensus, dynamic networks, averaging algorithms |
Collection: |
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43rd International Colloquium on Automata, Languages, and Programming (ICALP 2016) |
Issue Date: |
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2016 |
Date of publication: |
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23.08.2016 |