Method and apparatus for fault-tolerant multiprocessing system recovery from power failure or drop-outs

摘要

Multiple processors are connected to form a multiprocessor system having interprocessor communicating capability. In the face of a power-fail signal, indicating that possible power loss is imminent, a processor will proceed through a shut-down procedure to save the present operating state so that when power is re-applied the processor can continue from the operating state it left when power was lost. The shut-down procedure concludes with the processor broadcasting messages to all other processors that it is undergoing a power-fail shut-down which is noted by the other processors to later cause them to enter a cautious mode of operation so as to not exclude the processor in any system configuration involving agreement of all processors by reason of the processor's loss of power.