Ics: a System for Imprecise Computations

The imprecise computation technique was introduced as a way to handle transient overload and to enhance the fault-tolerance of real-time systems. In a system based on this technique, each time-critical task is designed in such away that it can produce a usable, approximate result in time whenever a failure or overload prevents it from producing the desired, precise result. This paper describes an architecture that integrates the mechanism for the generation and use of approximate results with the traditional checkpointing mechanism. It then describes a system we are currently developing that implements this architecture.