Timing failure detection and real-time group communication in quasi-synchronous systems

This paper addresses the problem of having real-time group communication in systems that are not completely synchronous (quasi-synchronous). This situation can happen when load is not completely controlled thus not ruling out overload scenarios This is usually related to dynamic characteristics of the application and/or environment. Usually in such systems, temporal guarantees can only be made to the highest priority messages. In such scenario we propose to use the highest priority messages (ora dedicated synchronous channel if available) to implement a timing failure detection service. By using this service together with the communication protocols, we are able to provide safety in a timely fashion, which is of utmost importance for distributed fault-tolerant real-time applications.