2016/02/27 by Marcin Bieńkowski, Bienkowski, Marcin, Jan Marcinkowski +7
Computer Science · #Caching and Content Delivery #Optimization and Search Problems #Distributed systems and fault tolerance
paper · pdf · doi:10.48550/arxiv.1602.08563
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) * kALG/(kALG-kOPT+1)), where kALG and kOPT 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)).