J. Xu
A. Bondavalli
F. Di Giandomenico
University of Newcastle upon Tyne. 1994
This paper discusses the problem of attaining a flexible compromise between using redundancy to improve software dependability and limiting the amount of redundancy for efficiency. A new scheme for facilitating software fault tolerance, called the self-configuring optimal programming scheme (SCOP), is presented. The proposed scheme attempts to reduce the resource cost of software fault tolerance, both in space and time, by providing designers with a flexible redundant architecture in which dependability and efficiency can be combined dynamically at run time. The design methodology for SCOP introduces support techniques for flexibly adjusting various attributes of system services including reliability, throughput and response time. A detailed dependability and efficiency evaluation shows clearly that SCOP can achieve the same dependability level as those of other existing schemes for software fault tolerance, making good use of the available resources.