TY - GEN
T1 - An O(log k)-competitive algorithm for generalized caching
AU - Adamaszek, Anna
AU - Czumaj, Artur
AU - Englert, Matthias
AU - Räcke, Harald
PY - 2012
Y1 - 2012
N2 - In the generalized caching problem, we have a set of pages and a cache of size k. Each page p has a size wp ≥ 1 and fetching cost c p for loading the page into the cache. At any point in time, the sum of the sizes of the pages stored in the cache cannot exceed k. The input consists of a sequence of page requests. If a page is not present in the cache at the time it is requested, it has to be loaded into the cache incurring a cost of cp. We give a randomized O(log k)-competitive online algorithm for the generalized caching problem, improving the previous bound of O(log 2 k) by Bansal, Buchbinder, and Naor (STOC'08). This improved bound is asymptotically tight and of the same order as the known bounds for the classic problem with uniform weights and sizes. We follow the LP based techniques proposed Bansal et al. and our main contribution are improved and slightly simplified methods for rounding fractional solutions online.
AB - In the generalized caching problem, we have a set of pages and a cache of size k. Each page p has a size wp ≥ 1 and fetching cost c p for loading the page into the cache. At any point in time, the sum of the sizes of the pages stored in the cache cannot exceed k. The input consists of a sequence of page requests. If a page is not present in the cache at the time it is requested, it has to be loaded into the cache incurring a cost of cp. We give a randomized O(log k)-competitive online algorithm for the generalized caching problem, improving the previous bound of O(log 2 k) by Bansal, Buchbinder, and Naor (STOC'08). This improved bound is asymptotically tight and of the same order as the known bounds for the classic problem with uniform weights and sizes. We follow the LP based techniques proposed Bansal et al. and our main contribution are improved and slightly simplified methods for rounding fractional solutions online.
UR - http://www.scopus.com/inward/record.url?scp=84860146746&partnerID=8YFLogxK
U2 - 10.1137/1.9781611973099.133
DO - 10.1137/1.9781611973099.133
M3 - Conference contribution
AN - SCOPUS:84860146746
SN - 9781611972108
T3 - Proceedings of the Annual ACM-SIAM Symposium on Discrete Algorithms
SP - 1681
EP - 1689
BT - Proceedings of the 23rd Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2012
PB - Association for Computing Machinery
T2 - 23rd Annual ACM-SIAM Symposium on Discrete Algorithms, SODA 2012
Y2 - 17 January 2012 through 19 January 2012
ER -