Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 1 WP3.2 Replicazione Software Roberto Baldoni Riunione Annuale MAIS Roma 24 Novembre 2005

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 2 Replicazione Software Applicazione Client Oggetto Server (STATEFUL) Object Group Replication Logic Applicazione Client Tutti gli oggetti del gruppo devono evolvere secondo la stessa sequenza di stati Strong Replica Consistency

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 3 Approccio a 3 Livelli clcl c1c1 c2c2 r1r1 r2r2 client-tier end-tier rmrm Sistema Parzialmente Sincrono Sistema Asincrono Atomicità mid-tier Ordinamento Definisce un ordinamento totale delle richieste Garantisce latomicità dellesecuzione delle richieste hnhn h2h2 h1h1 sqsq s2s2 s1s1 R. Baldoni, C. Marchetti, S. Tucci Piergiovanni, A. Virgillito Fully Distributed Three-Tier Active Software Replication to appear on IEEE Transactions on Parallel and Distributed Systems 2006 R. Baldoni, S. Cimmino, C. Marchetti. A Classification of Total Order Specifications and its Application to Fixed Sequencer-based Implementations. to appear on Journal of Parallel and Distributed Computing

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 4 Una soluzione basata su middleware Adottare Interfacce Standard (FT-CORBA) Superare le limitazioni dello standard in termini di –Legacy Client –Interoperabilità Tramite 3T Replication –repliche leggere e asincrone –client autonomi

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 5 Architettura Object Request Broker Client Obj RM FN OGH IRL Client Obj IRL Stateful Object Group Obj Stateless Object Group Client OGH RM FN IRL Object Group Handler IRL Replication Manager IRL Fault Notifier Intra-component message bus Richieste a Stateful object group sono mediate da un mid-tier (OGH) replicato che garantisce consistenza Richieste a Stateless object group non sono mediate, non essendo necessario garantire consistenza I clients accedono ai servizi in maniera standard Tutte le comunicazioni tra oggetti distinti avvengono tramite IIOP I Server sono asincroni e indipendenti R. Baldoni, C. Marchetti Three-tier replication for FT-CORBA infrastructures. Software Practice & Experience 2004

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 6 IRL tecnologie utilizzate Piattaforme CORBA utilizzate –ORBACUS –ORBIX 2000 e IONA E2A –TAO Group Communication Toolkit –JGROUP –Maestro/Ensemble

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 7 Confronto di prestazioni Lavoro in preparazione 2T vs 3T Trovare scenari significativi secondo le proprietà dei canali del sistema replicato –Canale Affidabile –Canale non affidabili

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 8 Esperimento 3. Risultati(1) Request rateResponse-size 11KB Mean latencyStd dev a2T1103,12476,7 p2T787,621821,4 3T138,5366,56 Partiamo da request-rate pari a 1 e response-size pari a 1KB

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 9 Esperimento 3. Risultati(2) Request rateResponse-size 1001KB Mean latencyStd dev a2T3952,71544,9 p2T3230, T499,02194,25 Portiamo il request-rate a 100

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 10 Esperimento 3. Risultati(3) Request rateResponse-size 1004KB Mean latencyStd dev a2T3961,11544,1 p2T3230, T2705,71568 Portiamo il response-size a 4KB

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 11 Pubblicazioni e prototipi MAIS To appear workshops41 Conferences44 Journals2123 Tot6663 Prototipo open-source scaricabile dal sito midlab prototipo altamente citato in letteratura da surveys specifici oltre a circa 100 citazioni su google scholar forte interesse industriale (Selex-si, Elsag, Thales)

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 12 R. Baldoni, C. Marchetti, S. Tucci Piergiovanni, A. Virgillito Fully Distributed Three-Tier Active Software Replication to appear on IEEE Transactions on Parallel and Distributed Systems 2006 R. Baldoni, S. Cimmino, C. Marchetti. A Classification of Total Order Specifications and its Application to Fixed Sequencer-based Implementations. to appear on Journal of Parallel and Distributed Computing R. Baldoni, A. Milani, S. Tucci Piergiovanni, Optimal Propagation-based Protocols implementing Causal Memories To appear on Distributed Computing, ACM Springer-Verlag R. Baldoni, R. Beraldi, G. Cugola, M. Migliavacca, L. Querzoni Structure-less Content-Based Routing in Mobile Ad Hoc Networks In proceedings of the International Conference on Pervasive Services (ICPS '05), Santorini, Greece, July 2005 R. Baldoni, J. Hélary, S. Tucci Piergiovanni Group Reliable Communication in Ad-hoc Networks: a few Results and a Case Study. In proceedings of the International Conference on Pervasive Services (ICPS '05), Santorini, Greece, July 2005 R. Baldoni, C. Marchetti, A. Virgillito, R. Vitenberg. Content-Based Publish-Subscribe over Structured Overlay Networks 25th IEEE International Conference on Distributed Computing Systems ICDCS R. Baldoni, S. Cimmino, C. Marchetti Total Order Communications: a Practical Analysis 5th European Dependable Computing Conference, Budapest, Hungary, April 20-22, 2005 R. Baldoni, E. Barbi, S. Cimmino, C. Marchetti, P. Papa, L. Querzoni A Practical Comparison between the TAO Real-Time Event Service and the Maestro/Ensemble Group Communication System In proceedings of Distributed Objects and Applications (DOA) 2004, Larnaca, Cyprus R. Baldoni, R. Prakash Causality and the Spatial-Temporal Ordering in Mobile Systems. ACM MONET 9(5): (2004) R. Baldoni, R. Beraldi, L. Querzoni, A. Virgillito A Self-Organizing Crash-Resilient Topology Management System for Content-Based Publish/Subscribe. In Proceedings of the International Workshop on Distributed Event-Based Systems (DEBS '04), Edinburgh, Scotland, UK, May 2004

Università di Roma La Sapienza Dipartimento di Informatica e Sistemistica 13 R. Baldoni, R. Beraldi, L. Querzoni, A. Virgillito Subscription-Driven Self-Organization in Content-Based Publish/Subscribe In proceedings of the International Conference on Autonomic Computing, New York, USA, May 2004 C. Marchetti, B. Pernici, P. Plebani A Quality Model for Multichannel Adaptive Information Systems In Proceedings of the 13th International World Wide Web Conference (WWW04), NY, May 2004 R. Baldoni, A. Milani, S. Tucci Piergiovanni An Optimal Protocol for Causally Consistent Distributed Shared Memory Systems In proceedings of the International Parallel & Distributed Processing Symposium, Santa Fe, New Mexico, April 2004 R. Baldoni, R. Beraldi, S. Tucci Piergiovanni, A. Virgillito On the Modelling of Publish/Subscribe Communication Systems Concurrency and Computation: Practice and Experiences, Volume 17, Issue 12 (October 2005) R. Baldoni, R. Beraldi, S. Tucci Piergiovanni, A. Virgillito. Measuring Notification Loss in Publish/Subscribe Communication Systems In proceedings of the 10th International Symposium Pacific Rim Dependable Computing, Papeete, Tahiti, French Polynesia, March 2004 R. Baldoni, R. Beraldi, C. Marchetti, M. Patini A Middleware Architecture for Inter ad-hoc Networks Communication Workshop on Multi-channel and mobile information systems, a co-Located Event of WISE Rome (Italy), December 2003 C. Marchetti, B. Pernici, P. Plebani A quality model for e-Service based multi-channel adaptive information systems In Proceedings of the 1st Web Services Quality Workshop (WQW 2003), co-located with the (WISE03), Rome, Italy, 2003 R. Baldoni, C. Marchetti, S. Tucci Piergiovanni. A Three-tier Active Replication Protocol for Large Scale Distributed Systems IEICE Transactions on Information Systems: Special Issue on Dependable Computing-2003., volume D(12), num. 86, pages 2544–2552 R. Baldoni, M. Contenti, S. Tucci Piergiovanni, A. Virgillito Modelling Publish/Subscribe Communication Systems: Towards a Formal Approach. In Proceedings of Eighth IEEE International Workshop on Object-oriented Real-time Dependable Systems (WORDS 2003), Guadalajara, Mexico, January 15-17, 2003 R. Baldoni, S. Cimmino, C. Marchetti A Guided Tour On Total Order Specifications. in Proceedings of the /9-th IEEE International Workshop on Object-oriented Real-time Dependable Systems (WORDS 2003F), pp , October 2003, Capri Island, Italy R. Baldoni, C. Marchetti Three-tier replication for FT-CORBA infrastructures. Software Practice & Experience 2003 R. Baldoni, R. Beraldi A Caching Scheme for Routing in Mobile Ad Hoc Networks and Its Application to ZRP. IEEE Transactions on Computers, volume 52, num. 8, IEEE 2003