Summary: Designing Masking Fault­tolerance
via Nonmasking Fault­tolerance
Anish Arora Sandeep S. Kulkarni 1
Abstract
Masking fault­tolerance guarantees that programs continually satisfy their specifi­
cation in the presence of faults. By way of contrast, nonmasking fault­tolerance does
not guarantee as much: it merely guarantees that when faults stop occurring, pro­
gram executions converge to states from where programs continually (re)satisfy their
specification.
We present in this paper a component based method for the design of masking fault­
tolerant programs. In this method, components are added to a fault­intolerant program
in a stepwise manner, first, to transform a fault­intolerant program into a nonmask­
ing fault­tolerant one and, then, to enhance the fault­tolerance from nonmasking to
masking. We illustrate the method by designing programs for agreement in the pres­
ence of Byzantine faults, data transfer in the presence of message loss, triple modulo
redundancy in the presence of input corruption, and mutual exclusion in the presence
of process fail­stops. These examples also serve to demonstrate that the method accom­
modates a variety of fault­classes, it provides alternative designs for programs usually
designed with extant design methods, and it offers the potential for improved masking
fault­tolerant programs.

Source: Arora, Anish - Department of Computer Science and Engineering, Ohio State University

Collections: Computer Technologies and Information Sciences