A Representation Model for Virtual Machine Allocation

In Cloud Computing, the utilization of virtual machines (VMs) as a computational resource unit is a fundamental concept. In a Cloud environment, VMs are deployed on physical resources with a set computational characteristics, such as processing power. VMs have computational properties as well, which are drawn from their respective hosts, and may be migrated from one host to another. In this context, the perceived performance of a parallel application is determined by how the respective VMs are allocated to the physical resources. For instance, two VMs deployed in the same host may have their performance altered in complex ways, due to resource contention. Also, the efficiency of a application that spans many VMs is dependent on the distribution of the correspond ant processes, due to available communication bandwidth between VMs, but also due to the possibility of leveraging local communication between processes or threads in the shared memory of a single host. As an attempt to describe the complex conditions that influence the performance of applications running on the same Cloud environment, we propose a more detailed representation of VM allocation, with features that can be used in the future for building more accurate performance models.