Issues and Challenges in Security-aware Real-Time Scheduling for Distributed Systems
Task Scheduling for real-time distributed systems has been investigated extensively in the literature. However, conventional wisdom in dynamic scheduling ignores security requirements in realtime applications. As such, in addition to factoring quality of security in real-time applications running in the system, real-time scheduling algorithms need to be security-aware in nature. In this paper we first identify the open issues and challenges involved in designing and implementing security-aware real-time scheduling schemes, which are intended to consider both security and real-time constraints for distributed systems. Then five approaches towards achieving security aware in real-time scheduling are described: a security-aware architecture, a uniprocessor real-time scheduling algorithm with security awareness (EDF_OPTS) using a preliminary security overhead model and overall system performance metrics, security-aware real-time scheduling for homogeneous and heterogeneous distributed systems, and a feedback control mechanism to improve quality of security and schedulability in run time. Discussions on future security overhead models are also provided. Simulation results show that our EDF_OPTS algorithm significantly improves system performance in terms of quality of security and schedulability over three baseline algorithms under a wide range of workload characteristics.