An Optimized DHT for Linux Package Distribution

The rapid rising of Linux users requires P2P, an efficient content transport method, to distribute packages. Different from traditional streaming P2P systems, a P2P package distribution system is hazarded by the special characteristics of small package size and hot packages. Due to the small package size, DHT search performance, which is rarely considered in traditional P2P system, comes to be an important factor in package distribution process. To improve the DHT search performance in this circumstance, we propose four kinds of optimizations as follow. Firstly, Fast-Response is proposed to eliminate useless searches after having found the target pair. Secondly, LRU Cache is proposed to reduce search hops on the same package. Thirdly, Leap Cache is proposed to reduce the cache redundancy. Finally, Probability Cache, gathering those optimizing above and considering hot packages in addition, is proposed to get increase of cache hit rate and overall efficiency improvement. We simulate our optimizations using PeerSim platform. The results show that all the four optimizations get considerable improvement in performance. With the best situation of Probability Cache, 86.22% delay time of original Kademlia is saved.