P2P Networks and Distributed Systems

Peer-to-peer networks are distributed systems, where all participating entities both provide and utilize services to/from each other. Our research in P2P covers both unstructured and structured architectures (Distributed Hash Tables - DHTs).

XOROS

XOR Object Store (or XOROS for short) is a structured peer-to-peer system (Distributed Hash Table) designed with data updates in mind. Most current DHT implementations require that data values, once written, should not be modified. XOROS addresses this issue, by incorporating related distributed mutex and Byzantine-tolerant communication protocols at the peer-to-peer level.

Grid4All

We are developing a peer-to-peer filesystem for Grid4all, an EU funded research project that proposes a democratic grid, based on peer-to-peer technology.

HiPPIS Project

This is a system where multidimensional data organized in concept hierarchies are stored, indexed and queried in a fully distributed environment.

PASS It ON (PASSION) Project

In this project, we describe a distributed algorithm for adaptive load balancing in systems that support range queries. We address the issue of uneven load distribution among the peers that occurs when nodes index items of varying popularity.

Brown Dwarf Project

Brown Dwarf is a distributed system designed to efficiently store, query and update multidimensional data over a Peer-to-Peer overlay. It manages to answer both point and aggregate queries on-line through cooperating nodes that hold parts of a fully or partially materialized data cube. Updates are also performed on-line.