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arXiv · 1602.08563

Online Tree Caching

Marcin Bienkowski·Jan Marcinkowski·Maciej Pacut·Stefan Schmid·Aleksandra Spyra
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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)).

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Marcin Bienkowski, Jan Marcinkowski, Maciej Pacut, Stefan Schmid, Aleksandra Spyra. 2016-02-27. Online Tree Caching. https://arxiv.org/abs/1602.08563

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