Priority-based totally ordered multicast
L. Rodrigues, A Casimiro, and P. Veríssimo
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.
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
Also available extended report (gzip postscript), (pdf).