Title
Optimizing TTL Caches under Heavy-Tailed Demands.
Abstract
In this paper we analyze the hit performance of cache systems that receive file requests with general arrival distributions and different popularities. We consider timer-based (TTL) policies, with differentiated timers over which we optimize. The optimal policy is shown to be related to the monotonicity of the hazard rate function of the inter-arrival distribution. In particular for decreasing hazard rates, timer policies outperform the static policy of caching the most popular contents. We provide explicit solutions for the optimal policy in the case of Pareto-distributed inter-request times and a Zipf distribution of file popularities, including a compact fluid characterization in the limit of a large number of files. We compare it through simulation with classical policies, such as least-recently-used and discuss its performance. Finally, we analyze extensions of the optimization framework to a line network of caches.
Year
DOI
Venue
2016
10.1145/2896377.2901459
SIGMETRICS
Keywords
Field
DocType
caching algorithms, heavy-tails, performance evaluation
Zipf's law,Monotonic function,Cache,Computer science,Computer network,Cache algorithms,Real-time computing,Timer,Distributed computing
Conference
Volume
Issue
ISSN
44
1
0163-5999
ISBN
Citations 
PageRank 
978-1-4503-4266-7
12
0.53
References 
Authors
13
3
Name
Order
Citations
PageRank
Andrés Ferragut18514.23
Ismael Rodríguez2120.53
Fernando Paganini35912.18