,
Linda Thelen
Creative Commons Attribution 4.0 International license
We study the online service with deadlines (or delays) problem, in which a server must serve requests for points in a metric space while balancing travel distance and promptness of service. While the problem has been extensively studied (STOC 2017), (FOCS 2019), (FOCS 2023), the main open question whether a constant competitive ratio can be achieved remains wide open. We prove a logarithmic lower bound for a natural class of algorithms already on uniform line metrics. Our lower bound applies to, and is tight for, the best known algorithms for general metrics and uniform line metrics.
@InProceedings{disser_et_al:LIPIcs.ISAAC.2025.26,
author = {Disser, Yann and Thelen, Linda},
title = {{A Tight Lower Bound for Online Service with Deadlines and Lazy Server}},
booktitle = {36th International Symposium on Algorithms and Computation (ISAAC 2025)},
pages = {26:1--26:17},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-408-6},
ISSN = {1868-8969},
year = {2025},
volume = {359},
editor = {Chen, Ho-Lin and Hon, Wing-Kai and Tsai, Meng-Tsung},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ISAAC.2025.26},
URN = {urn:nbn:de:0030-drops-249347},
doi = {10.4230/LIPIcs.ISAAC.2025.26},
annote = {Keywords: online algorithms, competitive analysis, lower bound, delay, deadlines}
}