“…2,20,25,26,31,36,[40][41][42][43][44] However, some also consider the placement of a single VM 11,45 or a set of VMs belonging to the same application. 24,46,47 • New placement vs re-optimization. For the given VM set (whether it is the set of all VMs of the DC, a single VM, or the VMs of an application), there are 2 different problem variants: Either the initial placement of the VMs needs to be determined 11,19,31,41,46,48 or their existing placement is to be re-optimized to adapt it to the changed resource requirements of the workload.…”