1. A non-transitory computer-readable storage medium storing a program for causing a computer to execute a process, the process comprising: determining, for each of a plurality of virtual machines executed on a first information processing apparatus or a second information processing apparatus, whether the virtual machine is executing a first processing that is performed in response to a request from an external apparatus; first allocating, to the first information processing apparatus, first virtual machines, which are executing the first processing, among the plurality of virtual machines; and second allocating, to the second information processing apparatus, second virtual machines, which are not executing the first processing, among the plurality of virtual machines.