,
Thomas Sauerwald
,
Luca Zanetti
Creative Commons Attribution 4.0 International license
We study balanced allocations on graphs with removals. Load arrives at each edge e at an exponential rate and is then allocated to the vertex incident to e with the lowest current load. Load is removed from each vertex at an exponential rate. We identify a "conductance-like" quantity that determines if an equilibrium exists and allows us to bound the maximal load at equilibrium. Our analysis, based on simple potential function arguments, is very robust and can also handle noise in how the load is allocated. We also apply our general techniques to study the synchronous version of the process above, in which allocations and removals happen simultaneously at discrete time steps. We prove that, for any regular graph, in equilibrium, the expected difference in load across an edge, averaged over all edges, is at most 2. This implies, for example, that the two-choice process on the cycle has an O(n) gap between maximal and minimal load, improving the state-of-the-art by a log n factor.
@InProceedings{oleskertaylor_et_al:LIPIcs.AofA.2026.26,
author = {Olesker-Taylor, Sam and Sauerwald, Thomas and Zanetti, Luca},
title = {{Graphical Balanced Allocations with Removals}},
booktitle = {37th International Conference on Probabilistic, Combinatorial and Asymptotic Methods for the Analysis of Algorithms (AofA 2026)},
pages = {26:1--26:16},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-435-2},
ISSN = {1868-8969},
year = {2026},
volume = {381},
editor = {Panagiotou, Konstantinos},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.AofA.2026.26},
URN = {urn:nbn:de:0030-drops-262974},
doi = {10.4230/LIPIcs.AofA.2026.26},
annote = {Keywords: balanced allocations, load balancing, queueing networks, balls-into-bins, Markov chains}
}