José Orlando Roque Nascimento Pereira
Semantically Reliable Grup Communication.
Dissertação submetida para provas de doutoramento em Informática
Departamento de Informática, Faculdade do Minho, Julho de 2002.
Abstract
Current usage of computers and data communication networks for a
variety of daily tasks, calls for widespread deployment of fault
tolerance techniques with inexpensive off-the-shelf hardware and
software. Group communication is in this context a particularly
appealing technology, as it provides to the application programmer
reliability guarantees that highly simplify many fault tolerance
techniques.
It has however been reported that the performance of group
communication toolkits in large and heterogeneous systems is
frequently disappointing. Although this can be overcome by relaxing
reliability guarantees, the resulting protocol is often much less
useful than group communication, in particular, for strong
consistent replication. The challenge is thus to relax reliability
and still provide a convenient set of guarantees for fault tolerant
programming.
This thesis addresses models and mechanisms that by selectively
relaxing reliability guarantees, offer both the convenience of group
communication for fault tolerant programming and high performance.
The key to our proposal is to use knowledge about the semantics of
messages exchanged to determine which messages need to be reliably
delivered, hence semantic reliability. In many applications, some
messages implicitly convey or overwrite other messages sent recently
before, making them obsolete while still in transit. By omitting
only the delivery of obsolete messages, performance can be improved
without impact in the correctness of the application.
Specifications and algorithms for a complete semantically reliable
group communication protocol suite are introduced, encompassing
ordered and view synchronous multicast. The protocols are then
evaluated with analytical and simulation models and with a prototype
implementation. The discussion of a concrete application illustrates
the resulting programming interface and performance.
Selected Publications
- Semantically Reliable Multicast: Definition,
Implementation and Performance Evaluation.
- J. Pereira, L. Rodrigues and R. Oliveira.
- IEEE Transactions
on Computers, Special Issue on Reliable Distributed Systems, 2003 (to
appear).
- Available BibTeX, abstract (html).
- Semantically Reliable Grup Communication
- J. Pereira.
- PhD Thesis. Departamento de Informática da
Universidade do Minho
- Julho, 2002.
- Available pdf.
- Reducing the Cost of Group Communication with
Semantic View Synchrony.
- J. Pereira, L. Rodrigues
and R. Oliveira
- In Proceedings of The International Conference on
Dependable Systems and Networks (DSN), pp. 293-302, Washington, DC,
June, 2002.
- Available BibTeX, abstract and extended report(gzip postscript), (pdf).
- Semantically Reliable Broadcast: Sustaining High
Throughput in Reliable Distributed
Systems.
- J. Pereira, L. Rodrigues and
R. Oliveira
- In Concurrency in Dependable Computing, Paul
Ezhilchelvan and Alexander Romanovsky (eds.), Chapter 10. 2002 Kluwer
Academic Publishers, June 2002, ISBN 1-4020-7043-8.
- Available
BibTeX, abstract.
- Semantically Reliable Multicast Protocols
- J. Pereira, L. Rodrigues and R. Oliveira.
- in
Proceedings of the 19th IEEE Symposium on Reliable Distributed
Systems, pp. 60-69, Nurnberg, Germany, October 2000.
- Available BibTeX, abstract (html) and extended report (gzip postscript), (pdf).
Contact
Luís Rodrigues