Details:

Journal Title:
Geoscientific Model Development
Personal Author:
Yang, Rui ; Ward, Marshall ; Evans, Ben
Yang, Rui ; Ward, Marshall ; Evans, Ben Less -
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research) ; GFDL (Geophysical Fluid Dynamics Laboratory)
OAR (Oceanic and Atmospheric Research) ; GFDL (Geophysical Fluid Dynamics Laboratory) Less -
Description:
We present an implementation of parallel I/O in the Modular Ocean Model (MOM), a numerical ocean model used for climate forecasting, and determine its optimal performance over a range of tuning parameters. Our implementation uses the parallel API of the netCDF library, and we investigate the potential bottlenecks associated with the model configuration, netCDF implementation, the underpinning MPI-IO library/implementations and Lustre filesystem. We investigate the performance of a global 0.25 degrees resolution model using 240 and 960 CPUs. The best performance is observed when we limit the number of contiguous I/O domains on each compute node and assign one MPI rank to aggregate and to write the data from each node, while ensuring that all nodes participate in writing this data to our Lustre filesystem. These best-performance configurations are then applied to a higher 0.1 degrees resolution global model using 720 and 1440 CPUs, where we observe even greater performance improvements. In all cases, the tuned parallel I/O implementation achieves much faster write speeds relative to serial single-file I/O, with write speeds up to 60 times faster at higher resolutions. Under the constraints outlined above, we observe that the performance scales as the number of compute nodes and I/O aggregators are increased, ensuring the continued scalability of I/O-intensive MOM5 model runs that will be used in our next-generation higher-resolution simulations.
Keywords:
[+]
Climatology Ocean Circulation
Source:
Geosci. Model Dev., 13, 1885–1902, 2020 https://doi.org/10.5194/gmd-13-1885-2020
DOI:
https://doi.org/10.5194/gmd-13-1885-2020
Document Type:
Journal Article
Rights Information:
CC BY
Compliance:
Submitted
Main Document Checksum:
[+]
urn:sha256:5c670d12c51ac5fcd6fae73e1100a2f6f86088dbb4f6a80efcd42d4914048879
Download URL:
https://repository.library.noaa.gov/view/noaa/29958/noaa_29958_DS1.pdf
File Type:

Supporting Files

• 	Machine Readable Version	xml
  	Machine Readable Version	xml
  	Available dataset	htm
  	Available dataset	htm

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