1. 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

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

3. 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

4. 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

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

6. 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

7. 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

8. 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.

9. 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.