Job preemption, fast subcube compaction, or waiting in hypercube systems? A selection methodology
For a hypercube environment, this paper proposes a decision making method that tries to answer the following question: when a fully specified job arrives into a hypercube system and does not find an available free subcube that fulfills its execution requirements, what action to take: Preempt one of the running jobs, use its allocated subcube and resume it later. Do fast compaction for one of the allocated subcubes (using all disjoint paths method [IEEE Trans. Parallel Dist. Syst. 9 (1) (1998) 50]) to utilize a coalesced subcube area and run in it. Wait till one of the running jobs terminates and leaves the system. An algorithm of complexity is given to illustrate the selection methodology of a candidate job and the corresponding action, where N is the maximum number of jobs running in the hypercube system, and m is the maximum number of processing segments defined along one execution window. The action that causes a maximum time gain (maximum remaining laxities) is chosen. The selection approach enhances the preemption concept and can be incorporated into a job allocator for a hypercube system. Illustrative case studies are given to illustrate its applicability.
fast subcube compaction hypercubes laxities deadlines net time gain preemptive scheduling processing time rescheduling