Restoring Consistency after Network Partitions
2007 (English)Licentiate thesis, monograph (Other academic)
The software industry is facing a great challenge. While systems get more complex and distributed across the world, users are becoming more dependent on their availability. As systems increase in size and complexity so does the risk that some part will fail. Unfortunately, it has proven hard to tackle faults in distributed systems without a rigorous approach. Therefore, it is crucial that the scientific community can provide answers to how distributed computer systems can continue functioning despite faults.
Our contribution in this thesis is regarding a special class of faults which occurs whennetwork links fail in such a way that parts of the network become isolated, such faults are termed network partitions. We consider the problem of how systems that have integrity constraints on data can continue operating in presence of a network partition. Such a system must act optimistically while the network is split and then perform a some kind of reconciliation to restore consistency afterwards.
We have formally described four reconciliation algorithms and proven them correct. The novelty of these algorithms lies in the fact that they can restore consistency after network partitions in a system with integrity constraints and that one of the protocols allows the system to provide service during the reconciliation. We have implemented and evaluated the algorithms using simulation and as part of a partition-tolerant CORBA middleware. The results indicate that it pays oﬀ to act optimistically and that it is worthwhile to provide service during reconciliation.
Place, publisher, year, edition, pages
Institutionen för datavetenskap , 2007. , 111 p.
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1331
distributed systems, fault tolerance, network partitions, dependability, integrity constraints
National CategoryComputer Science
IdentifiersURN: urn:nbn:se:liu:diva-9913ISBN: 978-91-85895-89-2OAI: oai:DiVA.org:liu-9913DiVA: diva2:24228
2007-10-16, Visionen, Hus B, Campus Valla, Linköpings universitet, Linköping, 14:15 (English)
Ezhilchelvan, Paul, Dr.