Improve Replica Placement in Content Distribution Networks with Hybrid Technique

The increased using of the Internet and its accelerated growth leads to reduced network bandwidth and the capacity of servers; therefore, the quality of Internet services is unacceptable for users while the efficient and effective delivery of content on the web has an important role to play in improving performance. Content distribution networks were introduced to address this issue. Replicating and caching are the two main techniques to find the optimal substitute server for replicating the content in these networks. Most of the past research has focused on these two methods separately. In this paper, first the surrogate server’s storage divides into two regions for dynamic and static contents. Then with combining the cache and replication techniques, a heuristic hybrid method based on the greedy algorithm is proposed to add contents in dynamic or static cache regions. In this technique, any possible content is evaluated in each replication, and the best ones are selected and replicated according to the conditions. At the end the proposed approach evaluated in CDNsim environment and the results shown that the algorithm reduced average response time and maximize hit ratio.