Interactive Sessions

You could get an interactive session directly from your terminal, on compute nodes. Only short interactive jobs should be used (e.g., experimenting with new modifications to your Matlab code). You could also use the preempt partition for quick testing purposes. You can find more about it here

To start an interactive session, use srun command:

[wz22@login1]$ srun --pty -p preempt -t 30:00 -n 1 /bin/bash

Then you can run your applications on the terminal directly. E.g.,

[wz22@login1 ~]$ srun --pty -p preempt -t 30:00 -n 1 /bin/bash
srun: job 775175 queued and waiting for resources
srun: job 775175 has been allocated resources
[wz22@cn243 ~]$

In this example, user wz22 requested 1 CPU core (-n 1) on login node (login1) for 30 minutes on the high priority preempt partition. The system responded, assigned a job id (775175), queued the job and assigned 1 CPU core from one of the compute nodes (cn243) to the user.

Warning

In a real scenario, the system might be exhausted with no available resources to you. You need to wait in this circumstance.

With interactive session you can have the same arguments passed TO srun as you pass into the job script.

For example:

If you need an interactive session for 8 hours for one cpu and 8G of memory, you can run the follwoing command:

[wz22@login1 ~]$ srun -n 1 -m  8G -t 8:00:00 --pty /bin/bash
srun: job 775176 queued and waiting for resources
srun: job 775176 has been allocated resources
[wz22@c243 ~]$

To exit the interactive session, type Ctrl+d, or

[wz22@c243 ~]$ exit