摘要：The demand of storing and transferring user generated content (UGC) has been rapidly growing with the popularization of mobile devices equipped with video recording and playback capabilities. As a typical application of software-defined networks/network functions virtualization-based pervasive communications infrastructure, content delivery networks (CDNs) have been widely leveraged to distribute contents across different geographical locations. Nevertheless, the content delivery for UGC is inefficient with the existing “pull-based” caching mechanism in traditional CDNs, because there exists a huge volume of lukewarm or cold UGC which results in a low cache hit ratio. In this paper, we propose a “push-based” caching mechanism to efficiently and economically deliver UGC videos. Different from traditional CDNs which separate the original content storage and caching, we directly store UGC videos into selective servers which serve as both reliable storages and user-facing uploading servers. By carefully and dynamically selecting the storage locations of each UGC object based on its popularity and locality, we not only guarantee the data availability but also remarkably improve the content distribution performance and reduce the distribution cost.
