1. A cloud computing system comprising: a request reception unit configured to be realized by executing a request reception program that stores a message corresponding to a job in a storage unit in response to the reception of a processing request for the job from an information processing apparatus; a back-end processing unit configured to be realized by executing a back-end processing program that makes an acquisition request for the message to the storage unit at regular intervals, and when the message has been acquired from the storage unit, performs processing based on the acquired message; wherein a plurality of the back-end processing units is activated in the cloud computing system, and each back-end processing unit is incorporated into a processing execution unit that functions as an application, and a deletion unit configured not to delete an application that includes the process execution unit that is executing processes based on the message, but to delete the process execution unit that includes applications other than this application.