Issues in the Imprecise Computation Approach to Fault Tolerance

The imprecise computation technique can be used in a natural way to enhance fault tolerance. By providing a usable, approximate result whenever a failure or overload prevent the system from producing the desired, precise result, we can increase the availability of data and services, reduce the need for error-recovery operations, and minimize the costs in replication. This paper describes the domain-specific fault tolerance mechanisms that are needed to support the provision and correct usage of imprecise results for several representative application domains. The elements of an application-domain-independent architecture that can effectively integrate these domain-specific mechanisms are also described.