26.6 Remote model execution with PEcAn

The workhorse of remote model execution is the PEcAn.workflow::start_model_runs function, which distributes execution of each run in a list of runs (e.g. multiple runs in an ensemble) to the local machine or a remote based on the configuration in the PEcAn settings.

Broadly, there are three major types of model execution:

  • Serialized (PEcAn.remote::start_serial) – This runs models one at a time, directly on the local machine or remote (i.e. same as calling the executables one at a time for each run).
  • Via a queue system, (PEcAn.remote::start_qsub) – This uses a queue management system, such as SGE (e.g. qsub, qstat) found on the BU SCC machines, to submit jobs. For computationally intensive tasks, this is the recommended way to go.
  • Via a model launcher script (PEcAn.remote::setup_modellauncher) – This is a highly customizable approach where task submission is controlled by a user-provided script (launcher.sh).