CoopViz: Real Time Visualization of BitTorrent Swarm Dynamics Stefano Barbieri CoopViz: Real Time Visualization of BitTorrent Swarm Dynamics Master’s Thesis in Computer Engineering Parallel and Distributed Systems group Faculty of Electrical Engineering, Mathematics, and Computer Science Delft University of Technology Stefano Barbieri 3rd September 2009 Author Stefano Barbieri 1397052
[email protected] Title CoopViz: Real Time Visualization of BitTorrent Swarm Dynamics MSc presentation September 09, 2009 Graduation Committee dr. ir. D.H.J. Epema (chair) Faculty EEMCS, Delft University of Technology dr. ir. J. Pouwelse (University Supervisor) Faculty EEMCS, Delft University of Technology dr. ir. G. Gaydadjiev (Committee Member:) Faculty EEMCS, Delft University of Technology Abstract Peer to peer networks are only successful when a significant amount of users is willing to share their resources. In order to have highly efficient file sharing sys- tems, each user should upload to the other peers a number of bytes at least equal to the number of bytes he has downloaded from the community. Unfortunately many users show a selfish behavior, refusing to offer their upload bandwidth to other peers, thus limiting the efficiency of the networks. P2P clients implement different mechanisms in order to mitigate this misbehavior and improve cooperation; often, though, these policies are not enough to enforce altruism in peer-to-peer communi- ties. This thesis explores a new mean to stimulate users to give their fair contribu- tion to the P2P community; the final scope is to generate an emergent self-policing system where users take active part in determining the bandwidth allocation poli- cies. This is achieved by means of a graphical interface, CoopViz, that provides users with up-to-date insights into cooperative behavior of peers and allows the latter to vote on each other, showing their appreciation or disapproval.