SYSTEM AND METHOD FOR EFFECTUATING DISTRIBUTED CONSENSUS AMONG MEMBERS OF A PROCESSOR SET IN A MULTIPROCESSOR COMPUTING SYSTEM THROUGH THE USE OF SHARED STORAGE RESOURCES

A system and method for effectuating distributed consensus among members of a processor set in a multiprocessor computing system that is effective even when only a single surviving processor is operational and is achieved through joint implementation of a virtual state machine utilizing a sequence of numbered input commands. System synchronization is achieved by having all of the processors agree on the sequence of input commands so that they execute the same virtual state machine. Input commands are numbered consecutively and the processors use a set of shared stores (e.g. disk drives) to communicate amongst themselves requests (i.e. ballots) for new state machine inputs (or commands) and state machine inputs that have already been chosen (i.e. committed commands). A consensus process is used to decide upon (or commit) each command and this consensus is achieved using a majority of known system stores rather than a majority of known processors. Consequently, when consensus is achieved, it then exists on the system stores (e.g. the disk drives) and not in the processors.