Robust CDN replica placement techniques

Creating replicas of frequently accessed data objects across a read-intensive content delivery network (CDN) can result in reduced user response time. Because CDNs often operate under volatile conditions, it is of the utmost importance to study replica placement techniques that can cope with uncertainties in the system parameters. We propose four CDN replica placement heuristics that guarantee a robust performance under the uncertainty of arbitrary CDN server failures. By robust performance we mean the solution quality that a heuristic guarantees given the uncertainties in system parameters. The simulation results reveal interesting characteristics of the studied heuristics. We report these characteristics with a detailed discussion on which heuristics to utilize for robust CDN data replication given a specific scenario.