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We consider the generalized $k$-server problem on uniform metrics. We study the power of memoryless algorithms and show tight bounds of $\Theta(k!)$ on their competitive ratio. In particular we show that the \textit{Harmonic Algorithm}…

Data Structures and Algorithms · Computer Science 2020-07-20 Dimitris Christou , Dimitris Fotakis , 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

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

We initiate a formal study of fairness for the $k$-server problem, where the objective is not only to minimize the total movement cost, but also to distribute the cost equitably among servers. We first define a general notion of…

Data Structures and Algorithms · Computer Science 2025-12-25 Mohammadreza Daneshvaramoli , Helia Karisani , Mohammad Hajiesmaili , Shahin Kamali , Cameron Musco

We study three classical online problems -- $k$-server, $k$-taxi, and chasing size $k$ sets -- through a lens of smoothed analysis. Our setting allows request locations to be adversarial up to small perturbations, interpolating between…

Data Structures and Algorithms · Computer Science 2025-07-25 Christian Coester , Jack Umenberger

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

In this paper, we settle the randomized $k$-sever conjecture for the following metric spaces: line, circle, Hierarchically well-separated tree (HST). Specially, we show that there are $O(\log k)$-competitive randomized $k$-sever algorithms…

Data Structures and Algorithms · Computer Science 2015-10-28 Wenbin Chen

We study the design of computationally efficient randomized algorithms for the $k$-server problem. Existing randomized algorithms with the best known competitive ratios are, on the one hand, inherently implicit and, on the other hand,…

Data Structures and Algorithms · Computer Science 2026-05-05 Christian Coester , Romain Cosson

We consider the online $k$-taxi problem, a generalization of the $k$-server problem, in which $k$ servers are located in a metric space. A sequence of requests is revealed one by one, where each request is a pair of two points, representing…

Data Structures and Algorithms · Computer Science 2020-12-07 Niv Buchbinder , Christian Coester , Joseph , Naor

Resource allocation in distributed and networked systems such as the Cloud is becoming increasingly flexible, allowing these systems to dynamically adjust toward the workloads they serve, in a demand-aware manner. Online balanced…

Data Structures and Algorithms · Computer Science 2024-10-24 Harald Räcke , Stefan Schmid , Ruslan Zabrodin

The $k$-server conjecture, first posed by Manasse, McGeoch and Sleator in 1988, states that a $k$-competitive deterministic algorithm for the $k$-server problem exists. It is conjectured that the work function algorithm (WFA) achieves this…

Data Structures and Algorithms · Computer Science 2021-02-23 Christian Coester , Elias Koutsoupias

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

In this paper, we show that there is an O(log k log^2 n)-competitive randomized algorithm for the k-sever problem on any metric space with n points, which improved the previous best competitive ratio O(log^2 k log^3 n log log n) by Nikhil…

Data Structures and Algorithms · Computer Science 2015-10-28 Wenbin Chen

This paper presents a new extension of the classical Heron problem, termed the generalized $(k,m)$-Heron problem, which seeks an optimal configuration among $k$ feasible and $m$ target non-empty closed convex sets in $\mathbb{R}^n$. The…

Optimization and Control · Mathematics 2026-01-21 Triloki Nath , Manohar Choudhary , Ram K. Pandey

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

We consider the k-server problem under the advice model of computation when the underlying metric space is sparse. On one side, we show that an advice of size {\Omega}(n) is required to obtain a 1-competitive algorithm for sequences of size…

Data Structures and Algorithms · Computer Science 2013-05-10 Sushmita Gupta , Shahin Kamali , Alejandro López-Ortiz

We introduce the problem of $k$-chasing of convex functions, a simultaneous generalization of both the famous k-server problem in $R^d$, and of the problem of chasing convex bodies and functions. Aside from fundamental interest in this…

Data Structures and Algorithms · Computer Science 2020-04-17 Sébastien Bubeck , Yuval Rabani , Mark Sellke

In the online metric matching problem, $n$ servers and $n$ requests lie in a metric space. Servers are available upfront, and requests arrive sequentially. An arriving request must be matched immediately and irrevocably to an available…

Data Structures and Algorithms · Computer Science 2026-04-22 Yingxi Li , Ellen Vitercik , Mingwei Yang

The k-SERVER problem is one of the most prominent problems in online algorithms with several variants and extensions. However, simplifying assumptions like instantaneous server movements and zero service time has hitherto limited its…

Artificial Intelligence · Computer Science 2023-12-19 Daman Deep Singh , Amit Kumar , Abhijnan Chakraborty

In the classical Online Metric Matching problem, we are given a metric space with $k$ servers. A collection of clients arrive in an online fashion, and upon arrival, a client should irrevocably be matched to an as-yet-unmatched server. The…

Data Structures and Algorithms · Computer Science 2019-12-02 Varun Gupta , Ravishankar Krishnaswamy , Sai Sandeep