关键词: 非抢占式, 关键数据, 容错, 调度, 截止期, 比较

Abstract: In this paper, in accordance with the need of key data in real-time satellite system fault tolerance, and the key data with a relatively small number and a long cycle, it puts forward NP-PEDF-FT algorithm to realize high performance schedule. This algorithm based on EDF fault tolerant algorithm, adjusts the deadline of the key data through fault tolerance coefficient[λ]. This algorithm adjusts the deadline of the key data as the original deadline multiplied by the coefficient [(1-λ)]  to the queue of the tasks to send again, when the key data once transmission errors. So it can realize once fault tolerance. Of course, the algorithm will not send again and abandon the task, when the common data once transmission errors. NP-PEDF-FT algorithm is better when the coefficient[λ]is equal to 0.6 through the simulation. It also simulates the NP-PEDF-FT algorithm, NP-EDF-FT algorithm and NP-DP-FT algorithm, and compares the packet loss probability. It turns out that the NP-PEDF-FT algorithm used in this paper has a better effect.

Key words: non-preemptive, key data, fault tolerance, scheduled, deadline, compare