Enforcing Perfect Failure Detection

Perfect failure detectors can correctly decide whether a computer is crashed. However; it is impossible to implement a perfect failure detector in purely asynchronous systems. We show how to enforce perfect failure detection in timed distributed systems with hardware watchdogs. The two main system model assumptions are ( I ) each computer can measure time intervals with a known maximum error, and ( 2 ) each computer has a watchdog that crashes the computer unless the watchdog is periodically updated. We have implemented a system that satisfies both assumptions using a combination of off-the-shelfsofrwareare and hardware.