DiConic addition of failsafe fault-tolerance

We present a divide-and-conquer method, called DiConic, for automatic addition of failsafe fault-tolerance to distributed programs, where a failsafe program guarantees to meet its safety specification even when faults occur. Specifically, instead of adding fault-tolerance to a program as a whole, we separately revise program actions so that the entire program becomes failsafe fault-tolerant. Our DiConic algorithm has the potential to utilize the processing power of a large number of machines working in parallel, thereby enabling automatic addition of failsafe fault-tolerance to distributed programs with a large number of processes. We formulate our DiConic synthesis algorithm in terms of the satisfiability problem and demonstrate our approach for the Byzantine Generals problem and an industrial application. Copyright 2007 ACM