Apparatus and method for performing the backup of a primary database using a back up database

Claim 1

A method for automatic redundant network database management having at least two control system computers, a primary computer and a backup computer each of which has a database, said computers interconnected in a network, comprising the steps of: (A) initiating communication between said primary and backup computers; (B) communicating from each one of said primary and backup computers to the other of said primary and backup computers each change in the database associated with said one computer individually, for shadowing said change in said database of said one computer; (C) automatically updating the database of the other of said primary and backup computers with the changes made to the said one database; (D) discontinuing the communication between said primary and backup computers upon a detection by said primary computer of a failure of said network; (E) rolling back a shadowed transaction in progress in said backup computer when said communication is discontinued; (F) queuing, in said primary computer database, changes to the primary database upon said detection of the failure of said network; and (G) transmitting, from said primary computer, said queued database changes to said backup computer, upon reestablishing of communications in said network.

Claim 2

A method for automatic redundant network database management having at least two control system computers, a primary computer and a backup computer each of which has a database, said computers interconnected in a network, comprising the steps of: (A) initiating communication between said primary and backup computers; (B) communicating from each one of said primary and backup computers to the other of said primary and backup computers each change in the database associated with said one computer individually, for shadowing said change in said database of said one computer; (C) automatically updating the database of the other of said primary and backup computers with the changes made to the said one database; (D) discontinuing the communication between said primary and backup computers upon a detection by said primary computer of a failure of said network; (E) rolling back a shadowed transaction in progress in said backup computer when said communication is discontinued; (F) queuing, in said primary computer database, changes to the primary database upon said detection of the failure of said network; and (G) transmitting, from said primary computer, said queued database changes to said backup computer, upon reestablishing of communications in said network.

Claim 6

A system for backing up a primary database, comprising: a first computer having means for storing the primary database and a second computer, having means for storing a backup database; network means for connecting said first computer and said second computer; first means disposed in said first computer for producing a message indicating a change to said primary database and second means in said second computer for producing a respective message indicating each change in said backup database, individually; communication agent means disposed in said first computer and in said second computer, responsive to the respective messages produced by said first and second means, whereby any changes to said primary database are communicated to said backup database over said network for shadowing said change in said primary database; and means for discontinuing the communication between said first and second computers upon a detection by said first computer of a failure of said network; said second computer including means for rolling back a shadowed transaction in progress when said communication is discontinued; said first computer including means for queuing changes to the primary database upon said detection of the failure of said network; said first computer including means for transmitting said queued database changes to said second computer, upon reestablishing of communications in said network.

Claim 7

A system for backing up a primary database, comprising: a first computer having means for storing the primary database and a second computer, having means for storing a backup database; network means for connecting said first computer and said second computer; first means disposed in said first computer for producing a message indicating a change to said primary database and second means in said second computer for producing a respective message indicating each change in said backup database, individually; communication agent means disposed in said first computer and in said second computer, responsive to the respective messages produced by said first and second means, whereby any changes to said primary database are communicated to said backup database over said network for shadowing said change in said primary database; and means for discontinuing the communication between said first and second computers upon a detection by said first computer of a failure of said network; said second computer including means for rolling back a shadowed transaction in progress when said communication is discontinued; said first computer including means for queuing changes to the primary database upon said detection of the failure of said network; said first computer including means for transmitting said queued database changes to said second computer, upon reestablishing of communications in said network.