Pithos: a state persistency architecture for peer-to-peer massively multiuser virtual environments

An aspect of peer-to-peer (P2P) massively multiuser virtual environments (MMVEs) that has not received significant attention thus far, is how game objects can be stored in a distributed fashion, taking into account the unique aspects of MMVEs. The field is termed P2P MMVE state persistency. This paper explores the different models of state persistency for P2P MMVEs, namely super peer storage, overlay storage, hybrid storage and distance-based storage. All storage types are found to be lacking in some respects and therefore a novel storage system called Pithos is introduced. Pithos provides low latency storage for peers within the same group, while enabling higher latency, but reliable backup to a storage overlay. This is achieved by a two-tiered hybrid architecture making use of player grouping.