内容中心网络(CCN)是为了适应未来网络通信模式的转变，提供对可扩展和高效内容获取的原生支持而提出一种新型的网络体系架构，内容缓存机制是其研究的关键问题之一。现有机制在缓存节点的选择时往往过于集中，缓存负载分布严重不均，大大降低了网络资源利用率以及系统的缓存性能。该文提出一种基于缓存迁移的协作缓存机制，首先在缓存节点选择时考虑节点的中心性保证内容尽可能缓存在位置更重要的节点。同时，在缓存压力过大时，通过可用缓存空间大小、缓存替换率以及网络连接的稳定性等信息选择合适的邻居节点进行缓存内容的转移，充分利用邻居资源实现负载分担。仿真结果表明该机制能有效地改善缓存负载在节点上分布的均衡性，提高缓存命中率和缓存资源利用率并降低平均接入代价。%Content-Centric Networking (CCN) is a new Internet architecture with native support for scalable and efficient content acquisition, which is proposed to accommodate the changes in future communication mode. Content caching is one of the key issues in CCN. In some existing work, the choice of caching nodes is over-focused on few special nodes, which results in an uneven distribution of cached contents. It greatly decreases the utilization of network resources and impairs the overall caching performance. In this paper, a Cooperative Caching Mechanism with Content Migration (CCMCM) is proposed. In this scheme, the centrality of node is considered in the selection of caching nodes to ensure that contents can be cached in the more important nodes as much as possible. When the cached contents are extensive, the caching node can transfer some contents to the appropriate neighbor according to the cache space available, the cache replacement rate and the connection stability between nodes. The aim is to fully utilize the resource of neighbor nodes and achieve effective load distribution. Simulation results show that the proposed scheme improves the load balance among caching nodes, increases the resource utilization and achieves high cache hit rate with low average access cost.
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