|Ph.D Student||Melamed Roie|
|Subject||Scalable Services for Dynamic Wide-Area Environments|
|Department||Department of Computer Science||Supervisor||Professor Idit Keidar|
Peer-to-peer (P2P) systems are systems that rely primarily on the computing power and bandwidth of the participating nodes (peers) rather than on a central infrastructure. Such systems are scalable, robust, and can be easily deployed. Hence, P2P computing is a promising architecture for deploying distributed services over the Internet, as well as in mobile ad-hoc networks (MANETs). However, such an architecture also raises many research problems and challenges such as achieving scalability while incurring small load on each node, coping efficiency with failures and dynamic user behavior, and achieving fairness in a network with selfish users.
In this dissertation, we review these challenges, and present four P2P studies that address them in different settings. Araneola is a scalable reliable application-level multicast system for highly dynamic wide-area environments. EquiCast is a wide-area P2P multicast protocol for large groups of selfish nodes. Octopus is a fault-tolerant routing protocol for MANETs. And finally, we define metrics for evaluating unstructured overlays for P2P lookup systems, and evaluate different graphs and overlays according to these metrics.