A Cost-Effective Dynamic Content Migration Method in CDNs

Content Distribution Networks (CDNs) are highly advanced features for the Internet, and provide low latency, scalability, fault tolerance, and load balancing. One of the most important issues to realize these advantages of CDNs is to consider dynamic content allocation to deal with temporal load fluctuation. The dynamic content allocation provides mirroring of contents in order to distribute user accesses. Since user accesses for contents change depending on time, the contents need to be reallocated. In this paper, we propose a cost-effective content migration method named as a Step-by-Step (SxS) Migration Algorithm in CDNs. We can dynamically relocate contents while reducing the transmission cost by using our content migration method. We show that our method accomplishes sufficient performance and reduces the cost in comparison with the conventional shortest-path migration method. Furthermore, we present six life cycle models of contents to consider more realistic traffic pattern to the simulation experiments. Finally, we evaluate the availability of SxS Migration Algorithm for the dynamic content reconfiguration using our method across time.