Читать книгу Fog Computing - Группа авторов - Страница 43

Besides the process and task management aspects, tenants need to consider the cost of energy and tenancy. First, energy cost commonly refers to the energy consumption of battery-powered end-devices. Here, the tenants should optimize the application design and the runtime processes in order to minimize the energy consumption of the end-devices toward extending the sustainability of the overall processes.

Second, the cost of tenancy indicates the cost-performance trade-off of the application. Specifically, in some cases, the tenants intend to achieve the best agility in terms of task allocation, execution, and migration, they would pre-deploy the application at every single fog node that potentially will be encountered by the end-devices. For example, in the AAL-based application, the tenant might have deployed the application at all the fog nodes on the potential moving path of the patient in order to perform proactive fog-driven sensory data reasoning [18]. However, such an approach may demand a high tenancy cost for the tenant, especially when we consider that the patient (the end-device) may not encounter some of the fog nodes.