XOROS

Data redundancy in DHTs is commonly accomplished through automatic replication of values to a set of close participating nodes. Such copies, once written, should not be modified, as there is no inherent DHT function that can operate on a dynamic set of mutable replicas. To this end, we have designed and implemented XOROS - a system based on the Kademlia routing scheme, that addresses the problem by implementing a Byzantine-tolerant protocol for serializable data updates directly at the peer-to-peer level. Based upon related works that study distributed replica synchronization, mutual exclusion and communication in the presence of Byzantine behavior, we propose a unified DHT-based algorithm, that ties corresponding practices together in order to consistently propagate changes to all primary replicas of any key-value pair stored in the network. A multitude of applications may benefit from the resulting distributed read/write storage substrate as it retains all the advanced features of DHTs and is backwards compatible with existing put/get semantics.

More info at: http://xoros.cslab.ece.ntua.gr

Publications

• A. Chazapis and N. Koziris, "XOROS: A mutable Distributed Hash Table," in Proceedings of the 5th International Workshop on Databases, Information Systems and Peer-to-Peer Computing (DBISP2P 2007), Vienna, Austria, September 2007 [pdf]
• A. Zissimos, K. Doka, A. Chazapis and N. Koziris, "GridTorrent: Optimizing data transfers in the Grid with collaborative sharing," in Proceedings of the 11th Panhellenic Conference on Informatics (PCI2007), Patras, Greece, May 2007 [pdf]
• A. Chazapis, A. Zissimos, N. Koziris and P. Tsanakas, "Replica management services on the Grid: Evolving from a centralized design to a fully distributed, scalable and fault-tolerant peer-to-peer infrastructure," in Grid Technologies: Emerging from Distributed Architectures to Virtual Organizations, edited by M. P. Bekakos and G. A. Gravvanis, pp. 107-138, 2006, WIT Press, ISBN: 1-84564-055-1 [link]
• A. Chazapis, A. Zissimos and N. Koziris, "A peer-to-peer replica management service for high-throughput Grids," in Proceedings of the 2005 International Conference on Parallel Processing (ICPP05), Oslo, Norway, June 2005 [pdf]
• A. Chazapis and N. Koziris, "Storing and locating mutable data in structured P2P overlay networks," in Proceedings of the 10th Panhellenic Conference on Informatics (PCI2005), Volos, Greece, November 2005 [pdf]