Identifying Influential Factors of CDN Performance with Large-scale Data Analysis

Content Distribution Networks (CDNs) manage their own caching or routing overlay networks to provide reliable and efficient content delivery services. Currently, CDNs have become one of the most important tools on the Internet. They have been responsible for the majority of today's Internet traffic. The performance of CDNs directly influences the experiences of end users. In this paper, we develop several analyses to figure out the key factors influencing the overall performance of a CDN. The primary results demonstrate that the caching overlays and the routing overlays both have their own influential factors affecting CDN performance. Our results also show that the transmission latency between a surrogate and a content owner is a critical factor determining the overall performance of routing overlays. Furthermore, we argue that the surrogate assignment policy of a routing overlay need to seriously take this latency into account. Our analysis results provide a context for the CDN community on preferable surrogate assignment solutions.