Analysis of checkpointing for schedulability of real-time systems

Checkpointing is a relatively cost effective method for achieving fault tolerance in real-time systems. Since checkpointing schemes depend on time redundancy, they could affect the correctness of the system by causing deadlines to be missed. This paper provides exact schedulability tests for fault tolerant task sets under specified failure hypothesis and employing checkpointing to assist in fault recovery. The effects of checkpointing strategies on task response time are analysed and some insights for optimal checkpointing are provided. The emphasis here is on utilizing this analysis as an off-line design support tool.