Title
Improved Analysis of Online Balanced Clustering.
Abstract
In the online balanced graph repartitioning problem, one has to maintain a clustering of $n$ nodes into $\ell$ clusters, each having $k = n / \ell$ nodes. During runtime, an online algorithm is given a stream of communication requests between pairs of nodes: an inter-cluster communication costs one unit, while the intra-cluster communication is free. An algorithm can change the clustering, paying unit cost for each moved node. This natural problem admits a simple $O(\ell^2 \cdot k^2)$-competitive algorithm COMP, whose performance is far apart from the best known lower bound of $\Omega(\ell \cdot k)$. One of open questions is whether the dependency on $\ell$ can be made linear; this question is of practical importance as in the typical datacenter application where virtual machines are clustered on physical servers, $\ell$ is of several orders of magnitude larger than $k$. We answer this question affirmatively, proving that a simple modification of COMP is $(\ell \cdot 2^{O(k)})$-competitive. On the technical level, we achieve our bound by translating the problem to a system of linear integer equations and using Graver bases to show the existence of a ``small'' solution.
Year
DOI
Venue
2021
10.1007/978-3-030-92702-8_14
WAOA
DocType
Citations 
PageRank 
Conference
0
0.34
References 
Authors
0
6
Name
Order
Citations
PageRank
Marcin Bienkowski101.01
Martin Böhm231.77
Martin Koutecký301.69
Thomas Rothvoß400.34
Jiří Sgall500.68
Pavel Veselý601.69