Growing half-balls: Minimizing storage and communication costs in CDNs

Reuven Bar-Yehuda, Erez Kantor, Shay Kutten, Dror Rawitz

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


The Dynamic Content Distribution problem addresses the trade-off between storage and delivery costs in modern virtual Content Delivery Networks (CDNs). That is, a video file can be stored in multiple places so that the request of each user is served from a location that is near by to the user. This minimizes the delivery costs, but is associated with a storage cost. This problem is NP-hard even in grid networks. In this paper, we present a constant factor approximation algorithm for grid networks. We also present an O(logδ)-competitive algorithm, where δ is the normalized diameter of the network, for general networks with general metrics. We show a matching lower bound by using a reduction from online undirected Steiner tree. Our algorithms use a rather intuitive approach that has an elegant representation in geometric terms. © 2012 Springer-Verlag Berlin Heidelberg.


Dive into the research topics of 'Growing half-balls: Minimizing storage and communication costs in CDNs'. Together they form a unique fingerprint.

Cite this