Abstract
In this paper we consider the k-server problem where events are generated by selfish agents, known as the selfish k-server problem. In this setting, there is a set of k servers located in some metric space. Selfish agents arrive in an online fashion, each has a request located on some point in the metric space, and seeks to serve his request with the server of minimum distance to the request. If agents choose to serve their request with the nearest server, this mimics the greedy algorithm which has an unbounded competitive ratio. We propose an algorithm that associates a surcharge with each server independently of the agent to arrive (and therefore, yields a truthful online mechanism). An agent chooses to serve his request with the server that minimizes the distance to the request plus the associated surcharge to the server. This paper extends [9], which gave an optimal k-competitive dynamic pricing scheme for the selfish k-server problem on the line. We give a k-competitive dynamic pricing algorithm for the selfish k-server problem on tree metric spaces, which matches the optimal online (non truthful) algorithm. We show that an α-competitive dynamic pricing scheme exists on the tree if and only if there exists α-competitive online algorithm on the tree that is lazy and monotone. Given this characterization, the main technical difficulty is coming up with such an online algorithm.
Original language | English |
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Title of host publication | Approximation, Randomization, and Combinatorial Optimization. Algorithms and Techniques, APPROX/RANDOM 2019 |
Editors | Dimitris Achlioptas, Laszlo A. Vegh |
Publisher | Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing |
ISBN (Electronic) | 9783959771252 |
DOIs | |
State | Published - Sep 2019 |
Externally published | Yes |
Event | 22nd International Conference on Approximation Algorithms for Combinatorial Optimization Problems and 23rd International Conference on Randomization and Computation, APPROX/RANDOM 2019 - Cambridge, United States Duration: 20 Sep 2019 → 22 Sep 2019 |
Publication series
Name | Leibniz International Proceedings in Informatics, LIPIcs |
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Volume | 145 |
ISSN (Print) | 1868-8969 |
Conference
Conference | 22nd International Conference on Approximation Algorithms for Combinatorial Optimization Problems and 23rd International Conference on Randomization and Computation, APPROX/RANDOM 2019 |
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Country/Territory | United States |
City | Cambridge |
Period | 20/09/19 → 22/09/19 |
Bibliographical note
Publisher Copyright:© Ilan Reuven Cohen, Alon Eden, Amos Fiat, and Łukasz Jeż.
Funding
Funding Ilan Reuven Cohen: Partially supported by the ERC consolidator grant 617951. Alon Eden: Partially supported by the European Research Council under the European Unions Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement number 337122, by the Israel Science Foundation (grant numbers 317/17 and 1841/14). Amos Fiat: Partially supported by the Israel Science Foundation (grant number 1841/14). Łukasz Jeż: Partially supported by Polish National Science Centre grant 2016/22/E/ST6/00499.
Funders | Funder number |
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Seventh Framework Programme | 337122 |
European Commission | 617951 |
Israel Science Foundation | 1841/14, 317/17 |
Narodowe Centrum Nauki | 2016/22/E/ST6/00499 |
Seventh Framework Programme |
Keywords
- K-server problem
- Online algorithms
- Online mechanisms
- Online pricing