Data management in real-time systems: a case of on-demand updates in vehicle control systems

摘要

Real-time and embedded applications normally have constraints both with respect to timeliness and freshness of data they use. At the same time it is important that the resources are utilized as efficient as possible, e.g., for CPU resources unnecessary calculations should be lowered as much as possible. This is especially true for vehicle control systems, which are our targeting application area. The contribution of this paper is a new algorithm (ODTB) for updating data items that can skip unnecessary updates allowing for better utilization of the CPU. Performance evaluations on an engine electronic control unit for automobiles show that a database system using the new updating algorithm reduces the number of recalculations to zero in steady states. We also evaluate the algorithm using a simulator and show that the ODTB performs better than well-established updating algorithms (up to 50% more committed transactions).