Middleware of real-time object based fault tolerant distributed computing systems: issues and some approaches

At this turn of the century the object-oriented (OO) distributed real-time (RT) programming movement is growing rapidly along with the networked embedded systems market. The motivations are reviewed and then a brief overview is given of the particular programming scheme which this author and his collaborators have been establishing. The scheme is called the time-triggered message triggered object (TMO) programming scheme and it is used to make specific illustrations of the issues and potentials of OO RT programming. Fault tolerance capabilities are required in many distributed RT computing applications. At this time the development of middleware which is capable of supporting reliable fault-tolerant execution of application level RT distributed objects is an important challenge to the research community. Some major issues that need to be resolved and some promising approaches are discussed.