Title
Competitive Algorithms for Generalized k-Server in Uniform Metrics.
Abstract
The generalized k-server problem is a far-reaching extension of the k-server problem with several applications. Here, each server si lies in its own metric space Mi. A request is a k-tuple r = (r1,r2,..., rk) and to serve it, we need to move some server si to the point ri ∈ Mi, and the goal is to minimize the total distance traveled by the servers. Despite much work, no f(k)-competitive algorithm is known for the problem for k > 2 servers, even for special cases such as uniform metrics and lines. Here, we consider the problem in uniform metrics and give the first f(k)-competitive algorithms for general k. In particular, we obtain deterministic and randomized algorithms with competitive ratio k · 2k and O(k3 log k) respectively. Our deterministic bound is based on a novel application of the polynomial method to online algorithms, and essentially matches the long-known lower bound of 2k − 1. We also give a 22o(k) -competitive deterministic algorithm for weighted uniform metrics, which also essentially matches the recent doubly exponential lower bound for the problem.
Year
DOI
Venue
2018
10.5555/3174304.3175334
SODA '18: Symposium on Discrete Algorithms New Orleans Louisiana January, 2018
DocType
Volume
ISBN
Conference
abs/1707.04519
978-1-61197-503-1
Citations 
PageRank 
References 
0
0.34
0
Authors
4
Name
Order
Citations
PageRank
Nikhil Bansal13043230.41
Marek Eliás241.48
Grigorios Koumoutsos343.17
Jesper Nederlof429424.22