Dynamic Scheduling for Soft Real-Time Distributed Object Systems

Distributed real-time applications require flexible and dynamic scheduling mechanisms to provide timeliness guarantees to application objects. In this paper we present a new scheduling algorithm that exploits the task laxities and the object importances to make effective scheduling decisions. The algorithm uses current timing and resource measurements to determine the feasibility of the tasks and to distribute the objects to the processors. A task’s timing parameter (laxity value) is carried, from one processor to another, with the object invocations, yielding a system-wide scheduling strategy that requires only local computations. The algorithm aims to ensure that a low importance object does not delay the execution of a high importance task.