Publication

Title of proceedings	The IEEE 16th International Symposium on Parallel and Distributed Computing (ISDPC)
Place	Innsbruck, Austria
DOI	10.1109/ispdc.2017.23

URL	https://arxiv.org/pdf/1811.01344.pdf
Type of Open Access	Repository (Green Open Access)

Modern high performance computing (HPC) sys- tems exhibit a rapid growth in size, both “horizontally” in the number of nodes, as well as “vertically” in the number of cores per node. As such, they offer additional levels of hard- ware parallelism. Each level requires and employs algorithms for appropriately scheduling the computational work at the respective level. The present work explores the relation between two scheduling levels: batch and application. To understand and explore this relation, a novel simulation approach is presented that bridges two existing simulators from the two scheduling levels. A novel two-level simulator that implements the proposed approach is introduced. The two-level simulator is used to simulate all combinations of three batch scheduling and four application scheduling algorithms from the literature. These combinations are considered for allocating resources and executing the parallel jobs from a workload of a production HPC system. The results of the scheduling experiments reveal the strong relation between decisions taken at the two scheduling levels and their mutual influence. Complementing the simulations, the two-level simulator produces abstract parallel execution traces, which can visually be examined and illustrate the execution of different jobs and, for each job, the execution of its tasks at node and core levels, respectively.