Patent ID: 7849151

Claim:
A multiple computer system for replica memory updating comprising: a multiplicity of computers, each interconnected via at least one communications network, and each executing a different portion of an application program written to execute on a single computer, each having an independent local memory with at least one memory location being replicated in each said local memory, and a system for replica memory updating, said multiple computer system for replica memory updating comprising: at least one memory location having a specific location identifier and replicated on at least two machines, and updated to remain substantially similar upon occasion of a machine modifying its replica value; a plurality of sources each of which can update said memory location(s) and each of which utilizes an updating format for the signal or packet carrying out the updating, said format comprising the specific identifier of the memory location to be updated, the content with which said memory location is to be updated, and a resident updating count of the updating source, said count comprising a number indicative of the sequence of occasions on which the updating source has been updated inclusive of the current updating; storage means associated with each said memory location and in which the updating count of the previously received updating is stored; comparison means to compare the currently received updating count value with the presently resident updating count value and overwriting the associated replicated memory location with the currently received data content and overwriting the presently resident updating count with the currently received updating count, and (i) if the currently received updating count exceeds or is greater than the presently resident updating count, overwriting the associated replicated memory location with the currently received data content, and overwriting the presently resident updating count with the currently received updating count; or (ii) if the currently received updating count is less than the presently resident updating count, not overwriting the associated replicated memory location with the currently received data content, and not overwriting the presently resident updating count with the currently received updating count; and contention indicating means connected with said comparison means and operable to indicate a contention situation if the compared currently received updating count value and the presently resident updating count value are the equal.