Auteur / Autrice : | Sanja Petrovic |
Direction : | Philippe Nain, Patrick Brown |
Type : | Thèse de doctorat |
Discipline(s) : | Informatique |
Date : | Soutenance en 2008 |
Etablissement(s) : | Nice |
Ecole(s) doctorale(s) : | École doctorale Sciences et technologies de l'information et de la communication (Sophia Antipolis, Alpes-Maritimes) |
Mots clés
Résumé
The thesis concerns the performance of P2P file sharing applications such as eDonkey. These systems are characterized by a very large number of different shared files as well as a very large number of peers. The thesis studies the influence of file popularity on downloading times and the resulting unfairness which may result. A fluid model is introduced which allows to derive file downloading times as a function of file request rates and storage probability on user disks. An original and efficient numerical solution is proposed to solve the system for several hundred thousands of files. In addition measurements are performed on a population of 20000 ADSL users in the Nice area. These measurements are used to characterize file request rates and storage probabilities on user disks, as well as downloading times depending on the file requested. New and original solutions are introduced to solve the problems resulting from incomplete measurements and to obtain global statistics from local observations.