Reliable and Fault-Tolerant IoT-Edge Architecture

Edge computing has emerged as an effective solution for delay sensitive IoT applications. In the edge-cloud hierarchy, reliability and fault tolerance are important issues. This paper proposes a novel agent-based reliable and fault-tolerant hierarchical IoT-cloud architecture which can survive the failures of the edge servers. In the proposed architecture, the cloud is distributed over four levels (cloud-fog-mist-dew) based on the processing power and distance from the end IoT device. It makes the whole system reliable by replicating the data on the edge of the network. The proposed system is fault tolerant as it redirects the application on an alternate server. In case of a server's failure, redirection is done at the best possible level in the hierarchy, based on delay-tolerance of the IoT application. The application keeps on working even if the system fails on any level, on cloud, fog or mist. The solution is proposed using mobile agents (MAs) on servers to share systems' state and other important information with other agents in the hierarchy, to be used for application redirection in case of server's failure. The proposed system is simulated using Matlab and results prove its efficiency.