Global checkpointing for distributed programs

A novel algorithm for checkpointing and rollback recovery in distributed systems is presented. Processes belonging to the same program must take periodically a nonblocking coordinated global checkpoint, but only a minimum overhead is imposed during normal computation. Messages can be delivered out of order, and the processes are not required to be deterministic. The nonblocking structure is an important characteristic for avoiding laying a heavy burden on the application programs. The method also includes the damage assessment phase, unlike previous schemes that either assume that an error is detected immediately after it occurs (fail-stop) or simply ignore the damage caused by imperfect detection mechanisms. A possible way to evaluate the error detection latency, which enables one to assess the damage made and avoid the propagation of errors, is presented.