Datacenter: Data center is used to model the core services at the system level of a cloud infrastructure. It consists of a set of hosts which manage a set of virtual machines whose tasks are to handle “low level” processing, and at least one data center must be created to start the simulation.
Datacenter class is a CloudResource whose hostList are virtualized. It deals with processing of VM queries instead of processing Cloudlet-related queries. So, even though an AllocPolicy will be instantiated in the init() method of the superclass, it will not be used, as processing of cloudlets are handled by the CloudletScheduler and processing of VirtualMachines are handled by the VmAllocationPolicy.