Priority-based totally ordered multicast
L. Rodrigues, A. Casimiro and P. VerĂssimo
Selected sections of this report were published in the Proceedings of
the 3rd IFAC/IFIP workshop on Algorithms and Architectures for
Real-Time Control (AARTC'95). Ostend, Belgium, May 1995.
Abstract
The replicated state-machine approach is a general paradigm
to implement fault-tolerant services that is particularly useful in
real-time control applications. A totally ordered multicast protocol
is a well-known method to enforce replica determinism in this
approach. The paper presents an algorithm to provide a totally
ordered multicast delivery service that takes priorities into
account. The algorithm enforces the inter-replica coordination
required to guarantee that high priority messages can be delivered
before queued low priority messages that have not been delivered.
The algorithm as been implemented as a variant of a protocol
designed for local-area networks.
Also available as
INESC AR/16-95 (gzip postscript).