Paper Info
Title
P2P Second Life: Experimental Validation Using Kad
Abstract
Applications such as Second Life require massive deployment of servers worldwide to support a large number of users. We investigate experimentally how Peer-to-Peer (P2P) communication could help cut the deployment cost and increase the scalability of Social Virtual Worlds such as Second Life. We design and build a communication infrastructure that distributes the management of the virtual world among user resources using a structured P2P network. Our communication infrastructure is implemented on the top of Kad, the P2P network that supports millions of eMule users. We then use avatar and object traces collected on Second Life to perform a realistic emulation of P2P Second Life over the Internet. We show that, despite using a standard P2P solution, P2P Second Life is mostly consistent, persistent and scalable. However, the latency avatars experience to recover from an inconsistent view of the virtual world can become disturbing for very large numbers of participants and objects. We analyze and discuss this limitation and give recommendation on how to design P2P Social Virtual Worlds. I. I NTRODUCTION Social Virtual Worlds (SVWs) are networked virtual envi- ronments where people can invent and emulate a new social life. Second Life1 (SL), launched in 2003 by Linden Lab, has become the most popular SVW, reaching 14 million users in June 2008. SL consists of virtual regions where users interact via their digital representation called avatar. The main innovative feature of SL is that avatars can participate in t he design of the virtual environment by creating objects such as cars, trees, and buildings. Thus, SL differs from on line games where the virtual world is mostly static. SVWs must exhibit three major properties. First, all users must have a consistent view of the world. Second, no object should be lost; we call this property persistency of the virtual world. Third, the application must be scalable, i.e., the per- formance of the SVW must not be affected by the number of avatars and objects. Today, SVWs are implemented using a client/server archi- tecture. A server is used to maintain a unique state of the virtual world and to distribute it to the users. Client/serv er architectures are naturally consistent and persistent whe n communication is reliable. However, scalability is an issue as it depends on the number of servers deployed to support an unpredictable number of avatars and objects. In SL, the scalability issue is addressed by dividing the virtual worl d into regions that are each associated to a dedicated server. The number of avatars per region is limited to 100 and in case of server overload, the virtual world clock is slowed down. This
Year
DOI
Venue
2009
10.1109/INFCOM.2009.5062029
INFOCOM
Keywords
Field
DocType
Internet,avatars,peer-to-peer computing,Internet,Kad P2P network,P2P Second Life,avatar,peer-to-peer communication,social virtual world
World Wide Web,Software deployment,Computer science,Latency (engineering),Server,Computer network,Emulation,Avatar,Multimedia,Social virtual worlds,Scalability,The Internet
Conference
ISSN
Citations 
PageRank 
0743-166X
14
0.96
References 
Authors
11
3
Name
Order
Citations
PageRank
Matteo Varvello179748.31
Christophe Diot27831590.69
Ernst Biersack32176220.80