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Archivio digitale delle tesi discusse presso l’Università di Pisa

Tesi etd-03282008-105429


Tipo di tesi
Tesi di dottorato di ricerca
Autore
PUCCIANI, GIANNI
URN
etd-03282008-105429
Titolo
The Replica Consistency Problem in Data Grids
Settore scientifico disciplinare
ING-INF/05
Corso di studi
INGEGNERIA DELL'INFORMAZIONE
Relatori
Relatore Prof. Dini, Gianluca
Relatore Ing. Domenici, Andrea
Parole chiave
  • Database replication.
  • Grid
  • Replica synchronisation
  • Replication
Data inizio appello
09/06/2008
Consultabilità
Completa
Riassunto
Fast and reliable data access is a crucial aspect in distributed computing and is often achieved using data replication techniques. In Grid architectures, data are replicated in many nodes of the Grid, and users usually access the "best" replica in terms of availability and network latency. When replicas are modifiable, a change made to one replica will break the consistency with the other replicas that, at that point, become stale. Replica synchronisation protocols exist and are applied in several distributed
architectures, for example in distributed databases. Grid middleware solutions provide
well established support for replicating data. Nevertheless, replicas are still considered read-only, and no support is provided to the user for updating a replica while maintaining the consistency with the other replicas.
In this thesis, done in collaboration with the Italian National Institute of Nuclear
Physics (INFN) and the European Organisation for Nuclear Research (CERN), we study the replica consistency problem in Grid computing and propose a service, called CONStanza, that is able to synchronise both files and heterogeneous (different vendors) databases in a Grid environment. We analyse and implement a specific
use case that arises in high energy Physics, where conditions databases are replicated
using databases of different makes. We provide detailed performance results, and show how CONStanza can be used together with Oracle Streams to provide multitier replication of conditions databases using Oracle and MySQL databases.
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