Task scheduling in cloud-fog computing systems

Fog computing extends cloud services to the edge of the network. In such scenario, it is necessary to decide where applications should be executed so that their quality of service requirements can be supported. Thus, a cloud-fog system requires an efficient task scheduler to decide the locality where applications should run. This paper presents two schedulers based on integer linear programming, that schedule tasks either in the cloud or on fog resources. The schedulers differ from existing ones by the use of class of services to select the processing elements on which the tasks should be executed. Numerical results evince that the proposed schedulers outperform traditional ones, e.g., Random and Round Robin algorithms without causing violation of QoS requirements.