Patent ID: 6421741
Filing Date: 2002-07-16
Classification: G06F,H04L

Abstract:
A fault tolerant system using total order and normally operating in an active-replication mode comprising:a primary CPU normally operating in an active-replication mode; a backup CPU interconnected with the primary CPU, the backup CPU requiring synchronization with the primary CPU; means for sending an â€œadd meâ€  request signal from said backup CPU to said primary CPU to cause said primary CPU to temporarily switch to an active-standby mode; means for sending a â€œfinishedâ€  signal from said primary CPU to said backup CPU when copies of all data synchronization records have been transmitted to said backup CPU; and means causing both said primary and said backup CPUs to revert to an active-replication mode substantially immediately after transmission of said â€œfinishedâ€  signal.