Enhanced availability of transaction oriented systems using failure tests

For a transaction oriented system, the authors propose that in addition to the conventional recovery techniques, such as dumps and roll-back recovery, system availability be enhanced by the introduction of `failure tests´. They present a model to analyze the effect of the failure rate, the failure tests, and the periodic dumps, on global system availability. They then compute the optimum value of the interval between dumps, and also the best time interval between failure tests for this system. Numerical examples are presented for various failure models