QoS-aware object replica placement in CDNs

Recently, Content Distribution Networks (CDNS) have attracted a great deal of attention from both the industry and academic communities. We design efficient object replication algorithms to achieve the optimal performance while not violating clients' QoS requirements in CDN. We use a three-stage mechanism: First, object replication constraints to meet the QoS requirements are generated. Second, a minimal object replication set (MORS), which can satisfy the constraints with the minimal number of replicas on each server, is created. Finally, more objects are replicated on the servers with spare space to further improve the performance. We propose a number of heuristic algorithms and conduct trace-driven experiments to evaluate the performance.