Data Sharing in DHT Based P2P Systems
Lecture Notes in Computer Science
The evolution of peer-to-peer (P2P) systems triggered the building of large scale distributed applications. The main application domain is data sharing across a very large number of highly autonomous participants. Building such data sharing systems is particularly challenging because of the "extreme" characteristics of P2P infrastructures: massive distribution, high churn rate, no global control, potentially untrusted participants... This article focuses on declarative querying support, query
... timization and data privacy on a major class of P2P systems, that based on Distributed Hash Table (P2P DHT) . The usual approaches and the algorithms used by classic distributed systems and databases for providing data privacy and querying services are not well suited to P2P DHT systems. A considerable amount of work was required to adapt them for the new challenges such systems present. This paper describes the most important solutions found. It also identifies important future research trends in data management in P2P DHT systems. Introduction Peer-to-peer (P2P) systems take advantage of advances in networking and communication for providing environments where heterogeneous peers with high autonomy compose a system with a fully distributed control. P2P systems are the chosen platform for new style of applications where distributed data can be shared massively e.g., social networks , geo-collaboration systems , professional communities (medical, research, open-source software ). The development of massively distributed data sharing systems raises new and challenging issues. This results from the intrinsic characteristics of P2P systems (distribution among a huge number of peers, dynamic systems configuration, heterogeneity of data and peers, autonomy of data sources, very large This work is supported by the ECOS C07M02 action.