Abstract

Pithos: Distributed Storage for Massive Multi-User Virtual Environments HERMAN A. ENGELBRECHT and JOHN S. GILMORE, MIH Media Lab, Stellenbosch University There has been significant research effort into peer-to-peer (P2P) massively multi-user virtual environments (MMVEs). A number of architectures have been proposed to implement the P2P approach; however, the development of fully distributed MMVEs has met with a number of challenges. In this work, we address one of the key remaining challenges of state consistency and persistency in P2P MMVEs. Having reviewed state management and persistency architectures currently receiving research attention, we have identified deficiencies such as lack of load balancing, responsiveness, and scalability. To address these deficiencies, we present Pithos--a reliable, responsive, secure, load-balanced, and scalable distributed storage system, suited to P2P MMVEs. Pithos is designed specifically for P2P MMVEs, and we show that it improves the reliability and responsiveness of storage architectures as compared to existing P2P state persistency architectures. Pithos is implemented as an OverSim simulation running on the OMNeT++ network simulation framework. It is evaluated using up to 10,400 peers, with realistic latency profiles, with up to 15.8 million storage and retrieval requests that are generated to store a total of 2.4 million objects. Each