We report optimization work made in support of the development of a realtime Superfacility workflow between DIII-D and NERSC. At DIII-D, the ion properties measured by charge exchange recombination (CER) spectroscopy are required inputs for a Superfacility realtime workflow that computes the full plasma kinetic equilibrium. In this workflow, minutes matter since the results must be ready during the brief 10-15 minute pause between plasma discharges. Prior to this work, a sample CERFIT analysis took approximately 15 minutes. Because the problem consists of many calculations that can be done independently, we were able to restructure the CERFIT code to leverage this parallelism with Slurm job arrays. We reduced the runtime to approximately 51 seconds -- a speedup of roughly 20x, saving valuable time for both the scientists interested in the CER results and also for the larger equilibrium reconstruction workflow.

翻译：我们报告了为支持DIII-D与NERSC之间实时超设施工作流开发所进行的优化工作。在DIII-D装置中，通过电荷交换复合光谱测量得到的离子参数，是用于计算完整等离子体动力学平衡的超设施实时工作流所需的输入量。在该工作流中，时间至关重要——因为结果必须在等离子体放电之间短暂10-15分钟的间歇期内准备就绪。在此项工作之前，一次典型的CERFIT分析大约需要15分钟。由于该问题包含大量可独立完成的独立计算，我们得以重构CERFIT代码，利用Slurm作业阵列实现并行计算。我们将运行时间缩短至约51秒——实现了约20倍的加速，为关注CER结果的科学家以及更广泛的平衡重建工作流节省了宝贵时间。