TOPS: Two-phase scheduling for distributed real-time systems

In this work we propose a two-phase scheduling technique (TOPS) for distributed real-time systems. The first phase of TOPS is in charge of producing a scheduling sequence, whereas the second phase aims to dispatch tasks to computing nodes of a distributed system. The two phases are independent of one another and; therefore, one can change a policy in one phase without configuring another phase. TOPS makes it possible to observe the impacts of sorting policies on the performance of scheduling policies. We implement a TOPS prototype, in which the first phase is comprised of three sorting policies and the second phase consists of two scheduling policies in the second phase. TOPS enables us to discover that combining the EDF (Earliest-Deadline-First) and AEAP (As-Early-As-Possible) policies leads to an optimized performance among all the six candidate algorithms.