Distributed Asynchronous Real-Time Systems:
Language, Middleware Support and Application

Binoy Ravindran
Virginia Polytechnic Institute and State University

This talk will present resource management middleware techniques that enable the engineering of distributed real-time systems that are "asynchronous" both in the sense that processing and communication latencies do not necessarily have known upper bounds, and in the sense that event and task arrivals are non-deterministically distributed. Examples of distributed, asynchronous real-time systems include the emerging generation of command and control (C2) systems that must process data sets (radar tracks) and respond to event (threat) arrivals that have neither known upper bounds nor deterministic distributions, respectively. Distributed asynchronous real-time computer systems and their applications are inherently dynamic, and thus require end-to-end adaptive real-time resource management. We argue that the conventional "hard"/ "soft" dichotomy is too coarse, and timeliness is better treated as a quality of service (QoS) for activities that occur in such systems.

To enable the engineering of distributed asynchronous real-time systems, we present middleware architecture and services. The architecture includes a system specification language that allows a description of the system and its operational requirements (e.g., timeliness, survivability) as desired QoS, and resource management mechanisms for achieving the desired QoS. An abstract model that is constructed from the language specifications is used by the resource management algorithms for delivering the desired QoS. The resource management techniques revolve around the stages of QoS monitoring and failure detection, QoS diagnosis, and reallocation of resources to adapt the system to achieve acceptable levels of QoS. Experimental characterizations of the middleware using a distributed real-time C2 benchmark illustrate its effectiveness for delivering the desired QoS. Finally, we conclude by outlining the challenges in engineering systems like the future C2 surface combatants, on-going efforts, and future directions.

Biography:

Binoy Ravindran is an Assistant Professor with The Bradley Department of Electrical and Computer Engineering at Virginia Polytechnic Institute and State University, USA. He received his Ph.D. from the University of Texas at Arlington (UT Arlington), Master's degree from New Jersey Institute of Technology (NJIT), and Bachelor's degree from the University of Kerala, India. His principal research focus is on distributed asynchronous real-time systems having custom, application-level, end-to-end quality of services (e.g., timeliness, survivability).

Dr. Ravindran has been involved in the design and development of distributed real-time systems for the U.S Navy, particularly in the C2 context. He was instrumental in developing real-time resource management techniques that facilitate the engineering of future Navy shipboard surface combatants. He won an "Outstanding Research Award" from the College of Engineering at UT Arlington (1998) and two "Research Achievement Awards" from NJIT (1996) for outstanding research.