Fault-Tolerance for Distributed and Real-Time Embedded Systems Ostre Team Yves Sorel Bip Team Alain Girault Hamoudi Kalla Workshop DeFINE : Pisa - Italy November 26-27, 2002 Projet BIP

Outline Introduction: Real-Time Embedded System Fault-Tolerance: Our Methodology Proposed Methods Conclusion and Future Work

Introduction: real-time embedded system Failures models Sensors Architecture : processors and communications components Applications : C functions, Caml …. Actuators SynDEx tool implementation of real-time embedded applications on multicomponent architectures

Fault-Tolerance: Our Methodology High level program Compiler Architecture specification Distribution constraints Execution times Real-time constraints Failure specification Model of the algorithm Distribution heuristic Fault-tolerant distributed static schedule Code generator Fault-tolerant distributed embeded code

The Proposed Solutions: Models Algorithm Model in A B C D out P1 P2 P3 P4 Architecture Model

The Proposed Solutions: (1) Schedule 1 Schedule 1 Architecture Model P1 P2 P3 P4 Schedule Algorithm Model in A B out Failures Models Failure Model 1 P1 P2 P3 P4 Schedule 2 Fault-tolerant distributed static schedule Failure model 2 P1 P2 P3 P4 Schedule 3 Schedule 3

The Proposed Solutions: (2) B P1 P2 L.1-2-3 P3 L.3-4 P4 Architecture Model P1 P2 P3 P4 Algorithm Model in A B out in in send send Schedule N = 2 Failures Models N : Number of processor failures Fault-tolerant distributed static schedule

Conclusion & Future Work Develop a new fault-tolerance method, we take into account : Reliability Measures which is the probability that a component will not fail during a certain amount of time. Both processors and links failures.

References Catalin Dima, Alain Girault, Christophe Lavarenne, and Yves Sorel. Off-Line Real-Time Fault-Tolerant Scheduling. Euromicro Workshop on Parallel and Distributed Processing. Mantova, Italy, February 2001. Alain Girault, Christophe Lavarenne, Mihaela Sighireanu, and Yves Sorel. Fault-Tolerant Static Scheduling for Real-Time Distributed Embedded Systems. 21st International Conference on Distributed Computing Systems. Phoenix, USA, April 2001. Alain Girault, Christophe Lavarenne, Mihaela Sighireanu, and Yves Sorel. Generation of Fault-Tolerant Static Scheduling for Real-Time Distributed Embedded Systems with Multi-Point Link. IEEE Workshop on Fault-Tolerant Parallel and Distributed Systems. San Francisco, USA, April 2001.