PROGRAM wakeup_filter

Overview

Small auxiliary program for use in the “async=4” case where the main filter program is an MPI program and the model being run with DART is also an MPI program. The main MPI job script runs each of the model advances for the ensemble members, and then runs this program to restart the filter program.

Modules used

mpi_utilities_mod

Namelist

There are no namelist options for this program. It must be run as an MPI program with the same number of tasks as filter was originally started with.

Files

Named pipes (fifo) files are used to synchronize with the main MPI job run script, to ensure that the filter program and the script do not do a “busy-wait” in which they consume CPU cycles while they are waiting for each other. The fifo names are:

  • filter_to_model.lock

  • model_to_filter.lock

  • filter_lockNNNNN (where NNNNN is the task number with leading 0s)

References

  • Anderson, J., T. Hoar, K. Raeder, H. Liu, N. Collins, R. Torn, and A. Arellano, 2009: The Data Assimilation Research Testbed: A Community Facility. Bull. Amer. Meteor. Soc., 90, 1283-1296. DOI: 10.1175/2009BAMS2618.1