===== Comsol in batch, server or interactive mode. =====

==== Batch mode ====
A Step by step guide to use **Comsol MultiPhysics** in batch mode on the HPC/Slurm Cluster.

=== Initial setup. ===

  * Prepare a work folder for your comsol jobs and copy a template to submit these jobs.
<code bash>
mkdir ~/comsol
cd ~/comsol
cp /deepstore/software/examples/run-comsol.sbatch .
</code>
  * Modify the input/output files, required version of comsol, resource requirements (cpu/mem/gpu/nodes) etc. in the **run-comsol.sbatch** file.

=== Submit your comsol jobs. ===

  * Start your job by submitting the job using sbatch.
<code bash>
sbatch run-comsol.sbatch
</code>

==== Server Mode: ====
A Step by step guide to use **Comsol MultiPhysics Server** on the HPC/Slurm Cluster.

=== Initial setup. ===

  * Create a folder to store your comsol mphserver files and copy the example submit script.
<code bash>
mkdir ~/comsol
cd ~/comsol
cp /deepstore/software/examples/run-comsol-server.sbatch .
</code>
  * Modify the comsol server requirements, required version of comsol, resource requirements (cpu/mem/gpu/nodes) etc. in the **run-comsol-server.sbatch** file.
  * (Re)Set your comsol server password (this will start temporary the comsol server, close this after setting the password).
//This password will be stored in ~/.comsol/<version>/login.properties//
<code bash>
comsolpasswd
</code>

=== Starting the Comsol Server ===

  * Submit the job by running the following command :
<code bash>
sbatch run-comsol-server.sbatch
</code>
The command will show a **<job-id>**, wait until the job is actually running.
Use this **<job-id>** to check the content of the **comsol-server-<job-id>.log** file.
This will file will contain the required url to connect to the comsol-server using your local comsol-client.

=== Connect to the Comsol Server. ===

Use your **local** comsol to connect to your comsol server by using the Server name, port and username listed in the log file.
The content will probably look like this :
<code>
Adding Matlab r2019a
Adding Comsol MultiPhysics v5.3a
Server : ctit083.ewi.utwente.nl
Port : 8805
Username : laanstragj
COMSOL Multiphysics server 5.3a (Build: 348) started listening on port 8805
Use the console command 'close' to exit the program
</code>
The last two lines in the log file show the running comsol server.

  * Please terminate the comsol server when you are done
<code bash>
scancel <job-id>
</code>

==== Interactive Mode: ====
This will use the **[[:slurm:sinteractive|sinteractive]]** wrapper, this will depend on the availability of the requested resources !

=== Initial setup ===

Load the slurm utils software module (**[[:slurm:sinteractive|sinteractive]]**)
<code bash>
module load slurm/utils
</code>

Request resources using **[[:slurm:sinteractive|sinteractive]]** (optionally modify the default resources, default is : 2 cpu's for 1 hour.).
<code bash>
sinteractive --cpus-per-task=4 --time=1-0:0:0
</code>
Once the resources are claimed you will get a similar response as the following:
<code bash>
srun: job 164362 queued and waiting for resources
srun: job 164362 has been allocated resources
</code>
The result is that you will get a prompt on one of the compute nodes.

=== Start comsol ===

<code bash>
module load comsol/v5.6
comsol
exit
</code>

//Don't forget to exit the requested resources when you finish comsol (use the **exit** command) !//