Utility Accrual Object Distribution in Real-Time Systems

This paper considers object-based distributed real-time systems within which objects provide system services to the real-time tasks. Each task is subject to a time/utility function (TUF) which determines the accrued utility of the task according to its completion time. One major problem in such systems is to place the objects onto the computing nodes so as to maximize the total accrued utility. Thus, we propose a utility accrual object distribution (UAOD) algorithm which consists of two phases. In the first phase, through object placement and replication beside some types of deadline decomposition and adaptation, the computing nodes are reserved for the most beneficial tasks. As the second phase, UAOD follows a load-balancing algorithm for the placement of the remaining objects on the nodes to service the less beneficial tasks. Simulation results reveal that the total accrued utility is improved with the UAOD algorithm comparing to the traditional object placement methods.