Fault-Tolerant Strategies in the Tree-Based Fog Computing Model

In the Fog Comput$ing (FC) model of the Internet of Things (IoT), application processes to handle sensor data are distributed to fog nodes and servers. In the Tree-based FC (TBFC) model proposed by the authors, fog nodes are hierarchically structured. In this article, the authors propose a TBFC for a General Process (TBFCG) model to recover from the faults of fog nodes. If a node gets faulty, the child nodes are disconnected. The authors propose Minimum Energy in the TBFCG tree (MET) and selecting Multiple Parents for recovery in the TBFCG tree (MPT) algorithms to select a new parent node for the disconnected nodes. A new parent node has to process data from not only the disconnected nodes, but also its own child nodes. In the evaluation, the energy consumption and execution time of a new parent node can be reduced by the proposed algorithms.