Best Effort Query Processing in DHT-based P2P Systems (original) (raw)

Dynamic querying in structured peer-to-peer networks

2008

Dynamic Querying (DQ) is a technique adopted in unstructured Peer-to-Peer (P2P) networks to minimize the number of peers that is necessary to visit to reach the desired number of results. In this paper we introduce the use of the DQ technique in structured P2P networks. In particular, we present a P2P search algorithm, named DQ-DHT (Dynamic Querying over a Distributed Hash Table), to perform DQ-like searches over DHT-based overlays.

Enabling dynamic querying over distributed hash tables

2010

Dynamic querying (DQ) is a search technique used in unstructured peer-to-peer (P2P) networks to minimize the number of nodes that is necessary to visit to reach the desired number of results. In this paper, we introduce the use of the DQ technique in structured P2P networks. In particular, we present a P2P search algorithm, named DQ-DHT (Dynamic Querying over a Distributed Hash Table), to perform DQ-like searches over DHT-based overlays.

Query Routing and Processing in Peer-To-Peer Data Sharing Systems

2010

Sharing musical files via the Internet was the essential motivation of early P2P systems. Despite of the great success of the P2P file sharing systems, these systems support only "simple" queries. The focus in such systems is how to carry out an efficient query routing in order to find the nodes storing a desired file. Recently, several research works have been made to extend P2P systems to be able to share data having a fine granularity (i.e. atomic attribute) and to process queries written with a highly expressive language (i.e. SQL). These works have led to the emergence of P2P data sharing systems that represent a new generation of P2P systems and, on the other hand, a next stage in a long period of the database research area. ? The characteristics of P2P systems (e.g. large-scale, node autonomy and instability) make impractical to have a global catalog that represents often an essential component in traditional database systems. Usually, such a catalog stores informat...

Data Sharing in DHT Based P2P Systems

2009

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 optimization 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.