ASA - The Adaptive Scheduling Architecture

In High Performance Computing (HPC), resources are controlled by batch systems and may not be available due to long queue waiting times, negatively impacting application deadlines. This is noticeable in low latency scientific workflows where resource planning and timely allocation are key for efficient processing. On the one hand, peak allocations guarantee the fastest possible workflows execution time, at the cost of extended queue waiting times and costly resource usage. On the other hand, dynamic allocations following specific workflow stage requirements optimizes resource usage, though it increases the total workflow makespan. To enable new scheduling strategies and features in workflows, we propose ASA: the Adaptive Scheduling Architecture, a novel scheduling method to reduce perceived queue waiting times as well as to optimize workflows resource usage. Reinforcement learning is used to estimate queue waiting times, and based on these estimates ASA pro-actively submit resource change requests, minimizing total workflow inter-stage waiting times, idle resources, and makespan. Experiments with three scientific workflows at two HPC centers show that ASA combines the best of the two aforementioned approaches, with average queue waiting time and makespan reductions of up to 10% and 2% respectively, with up to 100% prediction accuracy, while obtaining near optimal resource utilization.Originally included in thesis in manuscript form.