FPN: a distributed hash table for commercial applications

Distributed hash tables (DHTs) provide a scalable mechanism of mapping keys onto values. DHTs are designed for fully decentralized, yet efficient object location in peer-to-peer systems. The ad-hoc and dynamic nature of P2P networks motivated existing DHTs to keep only minimum state per node, resulting in relatively long routing paths. Moreover, since the storage in existing P2P systems is essentially "free", its utilization has not been the primary focus of DHT design, resulting in systems with poor utilization. We present fixed prefix network (FPN), a prefix-based DHT designed for future commercial P2P systems supporting applications like distributed archive repository and distributed DNS. Unlike traditional P2P, the new breed is built on the assumption that the contributed resources are dedicated to the system, and are significantly more stable. Exploiting this characterization, FPN allows trading of state size for routing length, making it possible to maintain short fixed path lengths for a wide range of number of nodes. Moreover, FPN guarantees the minimum storage utilization, and in practice can deliver an 80% utilization during the lifetime of a growing system. Finally, FPN is based on a simple concept, yet delivers scalability and robustness similar to other DHTs.