Janus: Build Gnutella-Like File Sharing System over Structured Overlay

. How to build an efficient and scalable p2p file sharing system is still an open question. Structured systems obtain O(log(N)) lookup upper bound by associating content with node. But they can not supporting complex queries. On the other hand, Gnutella-like unstructured systems support complex queries, but because of its random-graph topology and its flooding content discovery mechanism, it can not scale to large network systems. In this paper, we present Janus, which build unstructured file sharing system over structured overlay. Different from previous approaches, Janus keeps bidirectional links in its routing table. And with one-hop replication and biased random walk Janus make it possible to implement complex queries in the scalable manner. The experimental results indicate that, when the system running over a network of 10,000 peers, it only needs 100 hops to search half of the total system.