Patent ID: 7251813

Claim:
A server apparatus having a function of loading a new module stored in a storing device into a main memory and changing over from an old module to the new module, said server apparatus comprising: a virtual server control unit disposed in a virtual server Operating System (OS), for generating a plurality of virtual client Operating Systems (OSes) corresponding to one or more new modules to be started and for controlling the one or more new modules, including generating a first virtual client OS for one or more first new modules to be started based upon a file start instruction stored in said storing device; a boot control unit disposed in each virtual client OS, for loading said first new modules to be started into said main memory and starting said first new modules to be started; an identifier/module name conversion database (DB) managing unit disposed in said virtual server OS, for controlling dynamic assignment of an identifier to each said first new module to be started, registering a relation between module names of said first new modules and identifiers in a first table, and performing conversion between the module names of the first new modules and the identifiers; a routing control unit disposed in said virtual server OS, for routing a message sent from the first new modules started by the first virtual client OS to a second module started by a second virtual client OS different from the first virtual client OS based upon an identifier of said second module, said identifier registered in said first table; and a file update control unit disposed in said virtual server OS, for requesting said routing control unit to stop communication to an old module having a module name identical with the module names of the first new modules to be started and instructing said routing control unit to save a message to said old module and sweep out said message to the first new modules based upon, a file change instructions, wherein each virtual client OS controls communication between the one or more new modules started by each virtual client OS without using the routing control unit.