A Runtime Resource Management and Provisioning Middleware for Fog Computing Infrastructures

The pervasiveness and growing processing capabilities of mobile and embedded systems have enabled the widespread diffusion of the Fog Computing paradigm in the Internet of Things scenario, where computing is directly performed at the edges of the networked infrastructure in distributed cyber-physical systems. This scenario is characterized by a highly dynamic workload and architecture in which applications enter and leave the system, as well as nodes and connections. This article proposes a runtime resource management and provisioning middleware for the dynamic distribution of the applications on the processing resources. The proposed middleware consists of a two-level hierarchy: (i) a global Fog Orchestrator monitoring the architecture status and (ii) a Local Agent on each node, performing a fine-grain tuning of its resources. The co-operation between these components allows one to dynamically adapt and exploit the fine-grain nodes view for fulfilling the defined system-level goals, for example, minimizing power consumption while meeting Quality of Service requirements such as application throughput. This hierarchical architecture and the adopted policies offer a unified optimization strategy that is unique with regard to existing approaches that typically focus on a single aspect of resource management at runtime. A middleware prototype is presented and experimentally evaluated in a Smart Building case study.