Task scheduler for a fault tolerant multiple node processing system

TL;DR: In this paper, a task scheduler for a fault tolerant multiple node processing system has a task activity list storing a set of application tasks, a priority scan list storing selected portion of the set of tasks, and a completion status list also storing the same selected portions of the tasks.

Abstract: A task scheduler for a fault tolerant multiple node processing system having a task activity list storing a set of application tasks, a priority scan list storing a selected portion of the set of application tasks, a completion status list also storing the same selected portion of the set of application tasks. A wake-up sequencer transfers the application tasks from the task activity list to the priority scan list, and a priority scanner transfers the application tasks ready for execution from the priority scan list to a selection queue. A next task selector selects the next application task that its node will execute, and a task started register stores the identity of the application tasks completed by the other nodes. A task interactive consistency (TIC) handler updates the status of the application tasks stored in the task activity list, the priority scan list, and the completion status list in response to messages received from the other nodes identifying which nodes completed tasks. The task interactive consistency handler checks the scheduling process of each node by comparing the application tasks it reported to have started with the highest priority application task scheduled for that node in its selection queue.