Abstract

Resource allocation is one of the main influential factors to provide efficient and economical processing of resources in the infrastructure as a service Clouds. While there are many challenges in providing an efficient resource allocator, maximizing the utilization of physical resources is of great importance. There are several works focused on optimizing the selection of virtual machines (VMs) for migration, however, there is less attention on the placement of the selected VMs on the available physical machines, especially for the advanced reservation request model. In this paper, the placement method and the impacts of different parameters are studied. First, different states of the problem are classified. Then, an algorithm based on integer linear programming (ILP) is proposed to solve some common cases of the problem. Finally, the algorithm is implemented in a Haizea simulator and the results are compared with the Haizea greedy algorithm and some other heuristics. The results reveal that the Haizea greedy algorithm is not able to utilize around 40 % of the physical resources. Moreover, at low heterogeneity loads, the proposed ILP-based algorithm shows the same results as a Best-Fit algorithm, but at higher heterogeneity loads, the results of the proposed algorithm outperform other algorithms.