Multiple Fault Tolerance Patterns for Systems with Arbitrary Deadline

This paper aims to provide a fault tolerant scheduling algorithm that have fault tolerance patterns for periodic task with arbitrary deadlines. The fault tolerance is achieved by checkpointing where number of checkpoint is decided on the bases of the lemmas proposed. These patterns provide minimum tolerance to all the releases and an improved tolerance to some releases pertaining to the availability of the slack time. They may be binary (i.e., either provide maximum or minimum tolerance to a release) or greedy (i.e., provide an improved tolerance whenever it is possible) in nature. Theorems have been proposed to ensure that the task set is schedulable with at least minimum fault tolerance. The effectiveness of the proposed patterns have been measured through extensive examples and simulations.