Pace-Maker: Tracking peer availability in large networks

Fabrice Le Fessant (1) , Cigdem Sengul (1) , Anne-Marie Kermarrec (2)

1 ASAP - As Scalable As Possible: foundations of large scale dynamic distributed systems
2 ASAP - As Scalable As Possible: foundations of large scale dynamic distributed systems

Tracking peer availability in a peer to peer network is of utmost importance for many collaborative applications. For instance, such information is invaluable for identifying the most stable peers or group peers with similar uptime characteristics. However, as many applications tend to reward the most stable peers, there is a clear incentive for peers to attempt to lie about their uptime. In this paper, we present a scalable and lightweight protocol that enables nodes to measure the peer availability in the presence of malicious peers. In our protocol, each peer is in charge of maintaining its own availability over time by collecting heartbeats disseminated by a trusted entity using asymmetric cryptographic signatures. Hence, peers gain the ability to challenge other peers about the ability by checking that their real uptime matches the advertized one. Simulation results show that our protocol provides accurate availability measures, even when \%XX of the peers in the network are malicious. Furthermore, as the percentage of malicious peers increase beyond \%XX, our proposed system degrades gracefully.

Mots clés: peer-to-peer; cryptography; availability; monitoring

Domaines: Calcul parallèle, distribué et partagé [cs.DC]

Fabrice Le Fessant, Cigdem Sengul, Anne-Marie Kermarrec. Pace-Maker: Tracking peer availability in large networks. [Research Report] RR-6594, 2008, pp.33. ⟨inria-00305620v1⟩