Peer to peer systems have been widely used to alleviate the burden of servers by transferring to peers in a network tasks that do not require a centralization of the information. A wide range of applications are now emerging over peer-to-peer, such as social networking, multiplayer games, mobile messaging, etc.
Most of these applications are essentially data-centric, they rely on exchange of data between peers, and can be expressed by queries over the database.
We will demonstrate a tool that allows for such applications, programmed as a collection of queries over a database, to be ported seamlessly, without changing the initial queries, from a client/server system to peer-to-peer system.
The distribution is done with overlays network defined by declarative data centric programs specified in the Netlog language, thus resulting in a fully data centric modeling of the peer-to-peer application. The communication between peers relies on implicit addresses which can be evaluated on the fly to ensure the persistence of data.
We will demonstrate the technique on a multiplayer online game written in SQL with players who connect to a mobile ad hoc network. The overlay is defined by a combination of an ad hoc routing protocol, DSDV, together with a DHT.
