Dynamic Hardware Redundancy Approaches Towards Improving Service Availability in Fog Computing

The distributed nature of fog computing is designed to alleviate bottleneck traffic congestion which happens when a massive number of devices try to connect to more powerful computing resources simultaneously. Fog computing focuses on bringing data processing geographically closer to data source utilizing existing computing resources such as routers and switches. This heterogeneity nature of fog computing is an important feature and a challenge at the same time. To enhance fog computing availability with such nature, several studies have been conducted using different methods such as placement policies and scheduling algorithms. This paper proposes a fog computing model that includes an extra layer of duplex management system. This layer is designated for operating fog managers and warm spares to ensure higher availability for such a geographically disseminated paradigm. A Markov chain is utilized to calculate the probabilities of each possible state in the proposed model along with availability analysis. By utilizing the standby system, we were able to increase the availability to 93%.