università di roma la sapienza dipartimento di informatica e sistemistica 1 wp3.2 replicazione...

1

Università di Roma “La Sapienza”Dipartimento di Informatica e Sistemistica

WP3.2 Replicazione Software Roberto Baldoni

Riunione Annuale MAIS

Roma 24 Novembre 2005

2


Replicazione Software

Applicazione Client

Oggetto Server(STATEFUL)

Object Group

ReplicationLogic

Applicazione Client

Tutti gli oggetti del gruppo devono evolvere secondo la stessa sequenza di stati

Strong Replica Consistency

3


Approccio a 3 Livelli

cl

c1

c2

r1

r2

client-tier end-tier

rm

Sistema ParzialmenteSincrono

Sistema Asincrono

Atomicità

mid-tier

OrdinamentoDefinisce un

ordinamento totale delle richieste

Garantisce l’atomicità

dell’esecuzione delle richieste

hn

h2

h1

sq

s2

s1

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

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

5


Architettura

Object Request Broker

Client ObjObjObj

RM

RM

RM

FN

FN

FN

OGH

OGH

OGH

IRL

Client ObjObjObj

IRL

Stateful Object Group

ObjObjObj ObjObjObj

StatelessObject Group

ClientClient

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

6


IRL tecnologie utilizzate

• Piattaforme CORBA utilizzate– ORBACUS– ORBIX 2000 e IONA E2A– TAO

• Group Communication Toolkit– JGROUP– Maestro/Ensemble

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

8


Esperimento 3. Risultati(1)

Request rate Response-size

1 1KB

Mean latency Std dev

a2T 1103,1 2476,7

p2T 787,62 1821,4

3T 138,53 66,56

Partiamo da request-rate pari a 1 e response-size pari a 1KB

9




100 1KB


a2T 3952,7 1544,9

p2T 3230,8 1102

3T 499,02 194,25

Portiamo il request-rate a 100

10




100 4KB


a2T 3961,1 1544,1

p2T 3230,8 1102

3T 2705,7 1568

Portiamo il response-size a 4KB

11


Pubblicazioni e prototipi MAIS

2003 2004 2005 To appear

workshops 4 1

Conferences 4 4

Journals 2 1 2 3

Tot 6 6 6 3

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)

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 2005.

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): 507-516 (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

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 2003 - 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. 187-194, 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

università di roma la sapienza dipartimento di informatica e sistemistica 1 wp3.2 replicazione...

Documents

informatica e sistemistica

sapienza dipartimento

distributed computing

tier replication

e responsesize pari

affidabili slide

thales slide

stateful object group