%0 Journal Article %J Parallel Computing %D 2021 %T An international survey on MPI users %A Atsushi Hori %A Emmanuel Jeannot %A George Bosilca %A Takahiro Ogura %A Balazs Gerofi %A Jie Yin %A Yutaka Ishikawa %K message passing interface %K MPI %K survey %X The Message Passing Interface (MPI) plays a crucial part in the parallel computing ecosystem, a driving force behind many of thehigh-performance computing (HPC) successes. To maintain its relevance to the user community—and in particular to the growingHPC community at large—the MPI standard needs to identify and understand the MPI users’ concerns and expectations, and adaptaccordingly to continue to efficiently bridge the gap between users and hardware. This questionnaire survey was conducted usingtwo online questionnaire frameworks and has gathered more than 850 answers from 42 countries since February 2019. Some ofpreceding surveys of MPI uses are questionnaire surveys like ours, while others are conducted either by analyzing MPI programsto reveal static behavior or by using profiling tools to analyze the dynamic runtime behavior of MPI jobs. Our survey is differentfrom other questionnaire surveys in terms of its larger number of participants and wide geographic spread. As a result, it is possibleto illustrate the current status of MPI users more accurately and with a wider geographical distribution. In this report, we will showsome interesting findings, compare the results with preceding studies when possible, and provide some recommendations for MPIForum based on the findings. %B Parallel Computing %V 108 %8 2021-12 %G eng %U https://www.sciencedirect.com/science/article/abs/pii/S0167819121000983 %R 10.1016/j.parco.2021.102853