Online Tree Caching
Abstract
We initiate the study of a natural and practically relevant new variant of online caching where the to-be-cached items can have dependencies. We assume that the universe is a tree T and items are tree nodes; we require that if a node v is cached then the whole subtree T(v) rooted at v is cached as well. This theoretical problem finds an immediate application in the context of forwarding table optimization in IP routing and software-defined networks. We present an elegant online deterministic algorithm TC for this problem, and rigorously prove that its competitive ratio is O(height(T) * k_ALG/(k_ALG-k_OPT+1)), where k_ALG and k_OPT denote the cache sizes of an online and the optimal offline algorithm, respectively. The result is optimal up to a factor of O(height(T)).
Cite
@article{arxiv.1602.08563,
title = {Online Tree Caching},
author = {Marcin Bienkowski and Jan Marcinkowski and Maciej Pacut and Stefan Schmid and Aleksandra Spyra},
journal= {arXiv preprint arXiv:1602.08563},
year = {2017}
}