Research on Adaptive Content Delivery Networks to Follow Internet Load Dynamically

随着信息的快速传播和浏览器的无处不在，网络拥塞现象已经成为互联网上最严重的问题之一。所谓的内容交付（或分发）网络技术就是为了解决这个问题。然而，目前的CDN是静态的，不能动态地适应负载的增加或减少。本文的研究目的是设计和实现一个具有自主拓扑重组功能的自适应动态CDN。它根据需要从一组缓存代理中组织一个对等网络，这会吸收服务器不断增加的负载。我们设计了一些新的组件技术：（a）网络的过渡，（B）对等共享和合作，（c）自动访问重定向，（d）内容复制，和（e）它们的集成。最后给出了它们的原型实现和性能评估，证明了我们设计的优越性。当负载增加时，系统从一个普通的客户/服务器网络过渡到一个对等共享网络，并在需要时扩展对等网络，解决冲突并与其他相邻的对等网络协作。

With the rapid spread of information and ubiquitous accesses of browsers, congestion phenomena on the Internet have become one of the most serious issues. The technique called Content Delivery (or Distribution) Networks is to address this issue. However, corrent CDNs are static and unable to adapt to the increase or decrease of the load dynamically. Our research has aimed at desining and realizing an adaptive dynamic CDN with autonomous topology reorganization. It organizes a peer-to-peer network on demand from a group of cache proxies, which absorbs an increasing load to a server. We designed some new component technologies: (a) transition of networks, (b) peer-to-peer sharing and cooperation, (c) automatic access redirection, (d) content replication, and (e) their integration. Then we achieved their prototype implementations and performance evaluations, which prove advantages of our designs. Our system transits from a normal client/server network to a peer-to-peer sharing network when the load increases, and enlarges the peer-to-peer network if needed, with conflict resolution and cooperation with nother neighboring peer-to-peer networks.