[Nrg-l] Reminder: NRG Today @ 3pm - Abstract for today's talk

Jorge Londoño jmlon at cs.bu.edu
Mon Oct 1 08:08:07 EDT 2007

Today Flavio is going to present the paper:

"Modeling and Analysis of Seed Scheduling Strategies in a BitTorrent Network"
by Michiardi, Pietro; Ramachandran, Krishna; Sikdar, Biplap

BitTorrent has gained momentum in recent years as an effective means
of distributing digital content in the Internet. Despite the remarkable
scalability and efficiency properties that characterize BitTorrent in the
long haul, several studies identify the source of the content as the main
culprit for the poor performance of the system in a transient regime where
user requests for a popular content swamp the source and in case of high
node churn. Our work models the scheduling decisions made at the source
(called the seed) for selecting which pieces of the content to inject in
the system through a stochastic optimization process and provides an
analytical framework to compare different strategies.We define a new piece
selection algorithm (called proportional fair scheduling, PFS) that
incorporates the seed’s limited vision of the system dynamics in terms of
user requests so as to ensure a better content distribution among the
users. We prove convergence of PFS and compare its short and long term
performance against the mainline BitTorrent implementation and the “smart
seed” technique recently introduced in [9]. Our results show that PFS
induces substantial improvements on both system performance, by decreasing
the download time at the users, and system robustness against peer
dynamics, by quickly reacting to sudden changes in the request patterns of
the users.



More information about the Nrg-l mailing list