Agents and Peer-to-Peer Computing5th International Workshop, AP2PC 2006, Hakodate, Japan, May 9, 2006, Revised and Invited Papers

Peer-to-peer (P2P) computing has attracted significant media attention, initiallyspurred by the popularity of file-sharing systems such as Napster, Gnutella, andMorpheus.More recently systems like BitTorrent and eDonkey have continued tosustain that attention. New techniques such as distributed hash-tables (DHTs),semantic routing, and Plaxton Meshes are being combined with traditional conceptssuch as Hypercubes, Trust Metrics, and caching techniques to pool togetherthe untapped computing power at the “edges” of the Internet. These newtechniques and possibilities have generated a lot of interest in many industrialorganizations, and have resulted in the creation of a P2P working group on standardizationin this area (http://www.irtf.org/charter?gtype=rg&group=p2prg).In P2P computing, peers and services forego central coordination and dynamicallyorganize themselves to support knowledge sharing and collaboration,in both cooperative and non-cooperative environments. The success of P2P systemsstrongly depends on a number of factors. First, the ability to ensure equitabledistribution of content and services. Economic and business models whichrely on incentive mechanisms to supply contributions to the system are beingdeveloped, along with methods for controlling the “free riding” issue. Second,the ability to enforce provision of trusted services. Reputation-based P2P trustmanagement models are becoming a focus of the research community as a viablesolution. The trust models must balance both constraints imposed by theenvironment (e.g., scalability) and the unique properties of trust as a social andpsychological phenomenon. Recently, we are also witnessing a move of the P2Pparadigm to embrace mobile computing in an attempt to achieve even higherubiquitousness. The possibility of services related to physical location and therelation with agents in physical proximity could introduce new opportunities andalso new technical challenges.Although researchers working on distributed computing, multi-agent systems,databases, and networks have been using similar concepts for a long time, it isonly fairly recently that papers motivated by the current P2P paradigm havestarted appearing in high-quality conferences and workshops. Research in agentsystems in particular appears to be most relevant because, since their inception,multiagent systems have always been thought of as collections of peers.The multiagent paradigm can thus be superimposed on the P2P architecture,where agents embody the description of the task environments, the decisionsupportcapabilities, the collective behavior, and the interaction protocols ofeach peer. The emphasis in this context on decentralization, user autonomy, dynamicgrowth, and other advantages of P2P also leads to significant potentialproblems. Most prominent among these problems are coordination: the abilityof an agent to make decisions on its own actions in the context of activitiesof other agents; and scalability: the value of the P2P systems lies in how well they scale along several dimensions, including complexity, heterogeneity of peers,robustness, traffic redistribution, and so forth. It is important to scale up coordinationstrategies along multiple dimensions to enhance their tractability andviability, and thereby to widen potential application domains. These two problemsare common to many large-scale applications.Without coordination, agentsmay be wasting their efforts, squandering resources, and failing to achieve theirobjectives in situations requiring collective effort.This workshop series brings together researchers working on agent systems andP2P computing with the intention of strengthening this connection. Researchersfrom other related areas such as distributed systems, networks, and databasesystems are also welcome (and, in our opinion, have a lot to contribute). Weseek high-quality and original contributions on the general theme of “Agentsand P2P Computing.