Simulation Productions#

Simtools allows large-scale productions of simulated events required for the calculation of instrument response functions. Simtools is designed to use the CTAO workload management system (WMS) and the HT Condor job submission system.

Pre-requisites for running productions:

  • simtools is installed and configured on the job submission host.

  • simulation software (CORSIKA and sim_telarray) are installed on the worker nodes or installed in a container (findable through $SIMTOOLS_SIMTEL_PATH) .

  • simulation models are accessible through the simulation model database. This includes both the production tables and the model parameters.

  • configuration parameters for the production (see e.g., simulate_prod_gamma_20_deg_North.yml)

Productions are configured and submitted using the simtools-simulate-prod application (or simtools-simulate-prod-htcondor-generator for HTCondor jobs).

Local productions#

Configure and submit a local production using the simtools-simulate-prod command. The submit engine is configured with the --submit_engine local command line option, see simulate_prod_gamma_20_deg_North.yml for an example configuration.

Running a local production is a simple way to test the production system, but in general too slow to simulate a large number of events.

Running simtools on HTCondor using Apptainers#

Simtools can be run using HTCondor and Apptainers. Jobs are configured with the simtools-simulate-prod-htcondor-generator command. Configuration is similar to the simulate-prod command, with the following additions:

  • APPTAINER_IMAGE is the path to the Apptainer image to be used for the simulation.

  • PRIORITY is the priority of the job in HTCondor.

  • RUN_NUMBER and NUMBER_OF_RUNS are the first run number and the number of runs to be simulated.

The simtools-simulate-prod-htcondor-generator tool generates two files:

  • a condor submission file to specify the apptainer, the number of jobs (equals the number of runs), the priority, and the output files.

  • a condor submission script with the simtools-simulate-prod command to be run in the apptainer.

An example for the configuration simtools-simulate-prod-htcondor-generator can be found in simulate_prod_htcondor_generator_gamma_20_deg_North.yml.

Container images are available from the GitHub and CTAO container registries and can be converted to Apptainer images using the apptainer build command. Example:

apptainer build simtools.sif docker://ghcr.io/gammasim/simtools-prod-250304-corsika-78000-bernlohr-1.69-prod6-baseline-qgs3-avx2:20250507-154410

Running Grid Productions#

Danger

Missing Documentation.