Dynamic Provision of Computing Resources from Grid Infrastructures and Cloud Providers

Grid computing involves the ability to harness together the power of computing resources. In this paper we push forward this philosophy and show technologies enabling federation of grid infrastructures regardless of their interface. The aim is to provide the ability to build arbitrary complex grid infrastructure able to sustain the demand required by any given service. In this very same line, this paper also addresses mechanisms that potentially can be used to meet a given quality of service or satisfy peak demands this service may have. These mechanisms imply the elastic growth of the grid infrastructure making use of cloud providers, regardless of whether they are commercial, like Amazon EC2 and GoGrid, or scientific, like Globus Nimbus. Both these technologies of federation and dynamic provisioning are demonstrated in two experiments. The first is designed to show the feasibility of the federation solution by harnessing resources of the TeraGrid, EGEE and Open Science Grid infrastructures through a single point of entry. The second experiment is aimed to show the overheads caused in the process of offloading jobs to resources created in the cloud