Realization of Fault-Tolerant Home Network Management Middleware with the TMO Structuring Approach and an Integration of Fault Detection and Reconfiguration Mechanisms

A middleware model named ROAFTS (Real-time Object-oriented Adaptive Fault Tolerance Support) has been evolving in the UCI DREAM Lab. over the past decade as the core of a reliable execution engine model for fault-tolerant (FT) real-time (RT) distributed computing (DC) applications. It is meant to be an integration of various mechanisms for fault detection and recovery in a form that meshes well with high-level RT DC object-/component- based programming, in particular, TMO (Time-triggered Message-triggered Object) programming. Using ROAFTS as a backbone and low-layer middleware, we developed a model and a skeleton implementation for FT DC middleware providing efficient FT execution services for component-based home network applications. Capabilities for management of home information processing devices, including health monitoring of home devices, reconfiguration of device connections, and servicing queries on device status, were added to ROAFTS. Those additions were first designed as a network of high-level RT DC components, i.e., TMOs. Then the TMO network was extended into an FT TMO network by applying the replication scheme called the PSTR (Primary-Shadow TMO Replication) scheme and incorporating a component responsible for reconfiguring TMO replicas. This extension of ROAFTS is called ROAFTS-HNE (Home Network Extension) and its architecture is presented here. In addition, during the development of the ROAFTS-HNE model, we formulated a new approach for applying the PSTR scheme to RT DC components supported by ROAFTS. Finally, evaluations of the recovery times of a prototype implementation have been conducted.