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Related papers: Randomized $k$-server in polynomial time

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We study the randomized k-server problem on metric spaces consisting of widely separated subspaces. We give a method which extends existing algorithms to larger spaces with the growth rate of the competitive quotients being at most O(log…

Data Structures and Algorithms · Computer Science 2007-08-20 Judit Nagy-György

We give the first polylogarithmic-competitive randomized online algorithm for the $k$-server problem on an arbitrary finite metric space. In particular, our algorithm achieves a competitive ratio of O(log^3 n log^2 k log log n) for any…

Data Structures and Algorithms · Computer Science 2011-10-10 Nikhil Bansal , Niv Buchbinder , Aleksander Madry , Joseph , Naor

A natural variant of the classical online $k$-server problem is the Weighted $k$-server problem, where the cost of moving a server is its weight times the distance through which it moves. Despite its apparent simplicity, the weighted…

Data Structures and Algorithms · Computer Science 2024-10-10 Nikhil Ayyadevara , Ashish Chiplunkar , Amatya Sharma

We present an $O((\log k)^2)$-competitive randomized algorithm for the $k$-server problem on hierarchically separated trees (HSTs). This is the first $o(k)$-competitive randomized algorithm for which the competitive ratio is independent of…

Data Structures and Algorithms · Computer Science 2017-11-06 Sebastien Bubeck , Michael B. Cohen , James R. Lee , Yin Tat Lee , Aleksander Madry

The time-optimal $k$-server problem minimizes the time spent serving all requests instead of the distances traveled. We give a lower bound of $2k-1$ on the competitive ratio of any deterministic online algorithm for this problem, which…

Data Structures and Algorithms · Computer Science 2025-03-10 Fabian Frei , Dennis Komm , Moritz Stocker , Philip Whittington

We exhibit an $O((\log k)^6)$-competitive randomized algorithm for the $k$-server problem on any metric space. It is shown that a potential-based algorithm for the fractional $k$-server problem on hierarchically separated trees (HSTs) with…

Data Structures and Algorithms · Computer Science 2021-07-30 James R. Lee

We consider online algorithms for the $k$-server problem on trees. There is a $k$-competitive algorithm for this problem, and it is the best competitive ratio. M. Chrobak and L. Larmore provided it. At the same time, the existing…

Data Structures and Algorithms · Computer Science 2022-05-02 Kamil Khadiev , Maxim Yagafarov

In this paper, we study the weighted $k$-server problem on the uniform metric in both the offline and online settings. We start with the offline setting. In contrast to the (unweighted) $k$-server problem which has a polynomial-time…

Data Structures and Algorithms · Computer Science 2023-07-25 Anupam Gupta , Amit Kumar , Debmalya Panigrahi

We consider online algorithms for the $k$-server problem on trees of size $n$. Chrobak and Larmore proposed a $k$-competitive algorithm for this problem that has the optimal competitive ratio. However, the existing implementations have…

Data Structures and Algorithms · Computer Science 2024-04-05 Kamil Khadiev , Maxim Yagafarov

The weighted $k$-server problem is a generalization of the $k$-server problem in which the cost of moving a server of weight $\beta_i$ through a distance $d$ is $\beta_i\cdot d$. The weighted server problem on uniform spaces models caching…

Data Structures and Algorithms · Computer Science 2016-11-15 Ashish Chiplunkar , Sundar Vishwanathan

The generalized k-server problem is a far-reaching extension of the k-server problem with several applications. Here, each server $s_i$ lies in its own metric space $M_i$. A request is a k-tuple $r = (r_1,r_2,\dotsc,r_k)$ and to serve it,…

Data Structures and Algorithms · Computer Science 2017-07-18 Nikhil Bansal , Marek Elias , Grigorios Koumoutsos , Jesper Nederlof

We consider the online $k$-taxi problem, a generalization of the $k$-server problem, in which $k$ taxis serve a sequence of requests in a metric space. A request consists of two points $s$ and $t$, representing a passenger that wants to be…

Data Structures and Algorithms · Computer Science 2018-11-07 Christian Coester , Elias Koutsoupias

We study a variant of the $k$-server problem, the infinite server problem, in which infinitely many servers reside initially at a particular point of the metric space and serve a sequence of requests. In the framework of competitive…

Data Structures and Algorithms · Computer Science 2017-03-01 Christian Coester , Elias Koutsoupias , Philip Lazos

The weighted $k$-server problem is a natural generalization of the $k$-server problem in which the cost incurred in moving a server is the distance traveled times the weight of the server. Even after almost three decades since the seminal…

Data Structures and Algorithms · Computer Science 2021-07-15 Nikhil Ayyadevara , Ashish Chiplunkar

We study the $k$-server problem in the resource augmentation setting i.e., when the performance of the online algorithm with $k$ servers is compared to the offline optimal solution with $h \leq k$ servers. The problem is very poorly…

Data Structures and Algorithms · Computer Science 2017-04-12 Nikhil Bansal , Marek Eliáš , Łukasz Jeż , Grigorios Koumoutsos

In this paper, we study a stochastic variant of the celebrated k-server problem. In the k-server problem, we are required to minimize the total movement of k servers that are serving an online sequence of t requests in a metric. In the…

Data Structures and Algorithms · Computer Science 2017-06-01 Sina Dehghani , Soheil Ehsani , MohammadTaghi HajiAghayi , Vahid Liaghat , Saeed Seddighin

In this paper we study a dynamic resource allocation problem which we call the stochastic k-server problem. In this problem, requests for some service to be performed appear at various locations over time, and we have a collection of k…

Optimization and Control · Mathematics 2007-05-23 Randy Cogill , Sanjay Lall

We consider the $k$-server problem on trees and HSTs. We give an algorithm based on Bregman projections. This algorithm has a competitive ratios that match some of the recent results given by Bubeck et al. (STOC 2018), whose algorithm was…

Data Structures and Algorithms · Computer Science 2018-12-21 Niv Buchbinder , Anupam Gupta , Marco Molinaro , Joseph , Naor

We show how to restrict the analysis of a class of online problems that includes the $k$-server problem in finite metrics such that we only have to consider finite sequences of request. When applying the restrictions, both the optimal…

Data Structures and Algorithms · Computer Science 2013-03-13 Tobias Mömke

We study the resource augmented version of the $k$-server problem, also known as the $k$-server problem against weak adversaries or the $(h,k)$-server problem. In this setting, an online algorithm using $k$ servers is compared to an offline…

Data Structures and Algorithms · Computer Science 2020-04-22 Marcin Bienkowski , Jarosław Byrka , Christian Coester , Łukasz Jeż
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