A Survey of Peer-to-Peer Systems

Peer-to-Peer systems have become, in a short period of time, one of the fastest growing and most popular applications. The decentralized and distributed nature of p2p systems leads to living aside the client-server model. In p2p model each node takes both the roles of client and server. As a client, it can query and download its wanted data files from other nodes and as a server, it can provide data files to other nodes. Two main objectives in p2p systems are data location and search for interesting data. In order to present these topics, we survey various structured and unstructured p2p systems. We also study content-based p2p systems that are systems with clusters of nodes, according to the content of their data files. We point replication strategies and techniques and we show how range queries are performed.