Optimum checkpoints with age dependent failures

Summary This paper presents a method for obtaining the optimum checkpoint interval of a transaction processing computer system subject to time dependent failures. The system uses checkpointing to create a valid system state, and roll-back in order to recover from failures. Maximizing system availability we derive the optimum checkpoint interval as a function of the load of the system and of the time dependent failure rate. The results are illustrated numerically for the Weibull failure rate.On leave from Universidad de Los Andes, Venezuela