# Lecture

The Wandering Token - Congestion avoidance of a shared resource
23.11.2006
Speaker: Augusto Ciuffoletti, University of Pisa.
Date: 23 November 2006 Time: 11:00-13:00
Location: "Stelios Orphanoudakis" Seminar Room, FORTH, Heraklion, Crete.
Host:

Abstract:

In a distributed system where scalability is an issue, the problem of enforcing mutual exclusion often arises in a {\em soft} form: the infrequent failure of the mutual exclusion predicate is tolerated, without compromising the consistent operation of the overall system. For instance this occurs when the operation subject to mutual exclusion requires massive use of a shared resource. We introduce a scalable {\em soft mutual exclusion} algorithm, based on token passing: one distinguished feature of our algorithm is that instead of introducing an overlay topology we adopt a random walk approach. The consistency of our proposal is evaluated by simulation, and we examplify its use in the coordination of large data transfers in a backbone based network.

Bio:

Augusto Ciuffoletti is a researcher at the Department of Computer Science at the University of Pisa, where he teaches two courses about Internet. He established a strong collaboration with the Italian Institute of Nuclear Physics in the frame of their project for a Computing Grid, and participates to the CoreGRID project as an INFN member. His stay at FORTH institute is part of the of a CoreGRID activity.