Patent ID: 7389505

Claim:
A method comprising: receiving a software upgrade package for a software application; installing the software upgrade package for the software application on a secondary system; notifying instances of executing software modules of the software application on the secondary system that correspond to the software upgrade package of impending termination; terminating the instances of executing software modules of the software application on the secondary system; launching on the secondary system corresponding new instances of the software modules of the software application from the installed software upgrade package; switching the secondary system to become a new primary system, and an existing primary system to become a new secondary system; installing the software upgrade package for the software application on the new secondary system; notifying instances of executing software modules of the software application on the new secondary system that correspond to the software upgrade package for the software application of impending termination; and without interrupting an execution of the software application on the new secondary system, terminating the notified instances of executing software modules of the software application on the new secondary system, and launching on the new secondary system corresponding new instances of the software modules of the software application from the installed software upgrade package.