Using Light-Weight Groups to Handle Timing Failures in
Carlos Almeida and Paulo Veríssimo
From Proceedings of the 19th IEEE Real-Time Systems Symposium, December
1998, Madrid, Spain.
In a quasi-synchronous environment worst-case times
associated with a given activity are usually much higher than the
average time needed for that activity. Using always those worst-case
times can make a system useless. However, not using them may lead to
On the other hand, fully synchronous behavior is usually restricted to
small parts of the global system. In a previously defined architecture
we use this small synchronous part to control and validate the other
parts of the system.
In this paper we present a light-weight group protocol that
together with the previously defined architecture makes it possible to
efficiently handle timing failures in a quasi-synchronous
system. This is specially interesting when active replication is used. It
provides application support for a fail-safe behavior, or controlled
(timely and safe) switching between different qualities of service.
extended report (gzip postscript).