Workshop Final Report
From P2P Wiki
Pedro García López
Departament d'Enginyeria Informàtica i Matemàtiques University Rovira i Virgili, Spain pedro.garcia@urv.cat
Contents |
Introduction
The fourth International Workshop on Collaborative Peer-to-Peer Systems, COPS08 was held in Rome as part of WETICE-2008. It was the fourth meeting devoted to the study of the field of Cooperative Information Systems and P2P networks or Cooperative P2P-based Information Systems (COPS). In this edition, the chair responsabity for the workshop has changed from Michele Angelaccio to the professor Pedro Garcia Lopez. The workshop has been a success and it received 25 submissions (the maximum number of all COPS editions). After the review process, 6 full papers, 3 short papers and two invited papers were included in the final program.
The high quality submissions have demonstrated the relevance of the topic and and the recent trends in the peer-to-peer research community. The workshop was divided in three sessions: P2P algorithms, P2P middleware and social networks. Every paper addresses a hot topic in peer-to-peer research and relevant researchers in the area presented their recent contributions.
P2P Algorithms
Alberto Montresor (steering committee of IEEE P2P) opened the workshop with the invited paper entitled "Decentralized Network Analysis". He presented a provoking paper that opens up interesting research oportunities for applyng decentralized techniques to network analysis.
Shay Horovitz presented the paper "Collabory, A Collaborative Throughput Stabilizer & Accelerator for P2P Protocols". He proposed a novel idea based on helper ("feeder nodes") to achieve download rate stability in file sharing applications.
Finally, Lluis Pamies presented the paper "Reciprocal Exchange for Resource Allocation in Peer-to-Peer Networks". He introduced a novel reciprocal exchange algorithm that takes into account node's quality to achieve fair allocation of resources. The work is relevant in the timely problem of peer-to-peer data backup solutions.
P2P Middleware
Mike Sobolewski (specialist in federated service-oriented architectures) opened the session with the invited paper entitled "Federated Collaborations with Exertions". The paper describes a service-oriented P2P architecture and related federated metaprogramming model to support development of highly scalable and reliable distributed collaborative applications
Xavier Leon presented the paper entitled "Information and regulation in decentralized marketplaces for P2P-Grids". The paper shows how scalable systems benefit from distributed marketplaces supporting global information flow to regulate and optimize local and global behaviour. The paper addresses the important problem of economic inspired models in peer-to-peer computing.
Konstantin Pussep presented the paper entitled "On NAT Traversal in Peer-to-Peer Applications". This paper presents a lightweight framework for NAT traversal that contains the most important of NAT traversal techniques and makes it easily possible to establish connections with hidden peers. This is a recurrent and relevant problem of peer-to-peer environments.
Finally, Noel de Palma published the paper "A Self-Management Framework for overlay-based applications". This paper presents a self-management framework to deploy and manage distributed applications using middleware-level overlays.
Social Networks & Security
Oscar Boykin opened the session with the paper entitled "Social VPNs: Integrating Overlay and Social Networks for Seamless P2P Networking". The paper introduces the novel concept of Social VPN. It describes the architecture of such Social VPNs and a prototype implementation which integrates the Facebook API, IP-over-P2P virtual networks, and the IPsec security infrastructure in a virtual router. The paper received the Best Paper Award for COPS 08 edition.
Youssef Iraqui presented the paper "Personalized Recommendations in Peer-to-Peer Systems". The paper presents a novel peer-to-peer recommender scheme based on Peers’ Similarity and Weighted Files’ Popularity. These techniques increase peers’ satisfaction and contribution since peers will be motivated to download the recommended files and serve other peers meanwhile.
François Lesueur, presented the paper "Sybil-Resistant Admission Control Coupling SybilGuard with Distributed Certification". The papers proposes a sybil-resistant distributed admission control system which combines the social-based Sybil-Guard protocol with distributed certification. The paper aims to tackle each described aspect of the sybil attack, preventing users from creating many identifiers and enforcing the use of truly random identifiers.
Finally, Guillaume Urvoy-Keller presented the paper "Early Stage Denial of Service Attacks in BitTorrent: An Experimental Study". This paper addreses the relevant problem of security attacks to the popular Bittorrent protocol. The main conclusion that they present is that the BitTorrent is highly resilient to DoS Atacks as neither the ability to obtain a full copy of the content nor the actual replication speed are affected by the disconnection of the initial seed if the attack is not carried out at the very early stage of the session.
Conclusions
A clear conclusion of the workshop is that collaborative peer-to-peer systems is a vibrant area of research with relevant open problems. Peer-to-peer is transversal to many disciplines like Grid systems, pervasive environments, social networks and large-scale decentralized systems. Peer-to-Peer technologies have helped to overcome the current limitations of the Internet network. Novel services like application level multicast, overlay anycast, streaming, P2PTV, or Voice over IP demonstrate that the next generation services for Internet are based on peer-to-peer technologies.
In this line, the best paper award of COPS 08 (SocialVPN) introduces a novel infrastructure that breaks communication barriers by enabling SocialVPNs using IP-over-P2P services. We believe that Social Networks and peer-to-peer technologies will surely converge in the following years to create a new generation of collaboration and communication infrastructures.
