Fault-tolerance of functional programs based on the parallel graph reduction

Recently, parallel computing has been applied to many systems. Functional programming is suitable for parallel programming because of referential transparency and is applied to symbol processing systems and parallel database systems. Programs with some functional programming can be regarded as graphs and are processed in terms of reduction of the corresponding graph. The paper proposes fault tolerance of functional programming based on graph reduction. The proposed method stores the received graph as a message log and an erroneous task is recovered by using the checkpoint and the stored graph. Computer simulations reveal that the time overhead of the proposed method is small. If the checkpoint interval is 30 seconds and the number of tasks is 3, for example, the time overhead is less than 10%