A total of 6 CST licenses are available for use on the cluster.

Below are SLURM templates for two types of CST simulations. The first is primarily for undergraduate project students. The last one is only usable by certain postgraduate students and staff (the SLURM system limits the number of CPUs and memory available to different classes of users).

Please use the smallest feasible values for the simulation so that our cluster usage can be optimised.

Note: In the templates, there are various parameters you should change to reflect your simulation requirements. These parameters are indicated with <CHANGETHIS> tag. For example:

#SBATCH --mail-user=<CHANGETHIS>

This template, for a model with name cst_multi, is suitable for larger simulations that require more memory than is available on project lab computers and would typically run more than an hour on a lab computer. A single task is defined that will be allocated 4 CPU cores.

Typically values for –mem-per-cpu are 1000 (for 1G) or 2000 (for 2G) for larger simulations. Generally CST uses less memory than FEKO.

Note the –m is for CST MICROWAVE STUDIO and –q to use the integral equation solver. For other modes, see CST user guide.

cst_multi.slurm

#!/bin/bash
#SBATCH --output=<CHANGETHIS>.log
#SBATCH --job-name=<CHANGETHIS>
#SBATCH --cpus-per-task=4
#SBATCH --mem-per-cpu=<CHANGETHIS>
#SBATCH --licenses=cst:1
#SBATCH --time=<CHANGETHIS>
#SBATCH --mail-type=END
#SBATCH --mail-user=<CHANGETHIS>
 
# Run CST model simulation
srun /usr/local/CST/CST_STUDIO_SUITE/cst_design_environment --m --q --numthreads 4 cst_multi.cst

This template, for a model with name cst_max, is suitable for very large simulations that would require weeks to run on a desktop computer. A single task is defined that will be allocated 8 CPU cores. CST does not generally scale well beyond 8 threads.

Typically values for –mem-per-cpu are 1000 (for 1G) or 2000 (for 2G) for larger simulations. Generally CST uses less memory than FEKO.

cst_max.slurm

#!/bin/bash
#SBATCH --output=<CHANGETHIS>.log
#SBATCH --job-name=<CHANGETHIS>
#SBATCH --cpus-per-task=8
#SBATCH --mem-per-cpu=<CHANGETHIS>
#SBATCH --licenses=cst:1
#SBATCH --time=<CHANGETHIS>
#SBATCH --mail-type=END
#SBATCH --mail-user=<CHANGETHIS>
 
# Run CST model simulation
srun /usr/local/CST/CST_STUDIO_SUITE/cst_design_environment --m --q --numthreads 8 cst_max.cst

The following integration with the cluster scheduler makes it somewhat easier to use the clusters for CST simulations. However this approach requires default settings to be made which may not be suitable for all types of simulations. Specifically, the effective SLURM settings allocate 6 CPU cores with 1.5 GB per core, with a time limit of 20 hours. For larger / longer simulations one of the above templates should be used and the SLURM parameters appropriate for the simulation set explicitly. With the manual approach the job completion notification can also be set.

1. Ensure you have a working cluster username by logging into the head node.
2. Create a work directory for the CST front-end simulation uploads (should correspond with the “Work directory” setting below):
   • mkdir CST
3. Download the CST Cluster Integration Guide and Scripts from here: http://lftp.ee.up.ac.za/CST/Cluster/
4. Follow the instructions in section 4.2.3 starting on page 5. Use the following settings:
   • Hostname/IP of Scheduler Node: alpha1-1.ee.up.ac.za
   • CST Installation Path on Cluster: /usr/local/CST/CST_STUDIO_SUITE
   • Work directory (set your username correctly): /home/<USERNAME>/CST
   • The username and password are those used to log into the head node.

Jobs submitted will appear as a normal SLURM job (visible using squeue). Unfortunately the current integration scripts provided by CST do allow the progress of the simulation to be monitored. You can monitor the progress using the approach described in the next section.

Change to the top-level directory of the job work directory and use cst_progress. This will periodically show the contents of the “progress.log” file, which is normally used to indicate simulation progress on the CST front-end. Use Ctrl-C to cancel the file monitoring.