Large Memory Computing
Debugging

Interactive Jobs

To start an interactive session for running serial or threaded programs on an Oscar compute node, simply run the command interact from the login node:

interact

By default, this will create an interactive session that reserves 1 core and 4GB of memory for a period of 30 minutes. You can change the resources reserved for the session from these default limits by modifying the interact command:

usage: interact [-n cores] [-t walltime] [-m memory] [-q queue]
[-o outfile] [-X] [-f featurelist] [-h hostname] [-g ngpus]
Starts an interactive job by wrapping the SLURM 'salloc' and 'srun' commands.
options:
-n cores (default: 1)
-t walltime as hh:mm:ss (default: 30:00)
-m memory as #[k|m|g] (default: 4g)
-q queue (default: 'batch')
-o outfile save a copy of the sessions output to outfile (default: off)
-X enable X forwarding (default: no)
-f featurelist CCV-defined node features (e.g., 'e5-2600'),
combined with '&' and '|' (default: none)
-h hostname only run on the specific node 'hostname'
(default: none, use any available node)
-a account user SLURM accounting account name
-g ngpus number of GPUs

For example, the command

$ interact -n 20 -t 01:00:00 -m 10g

requests an interactive session with 20 cores and 10 GB of memory (per node) for a period of 1 hour.

Keeping Interactive Jobs Alive:

If you lose connectivity to your login node, you lose access to your interactive job. To mitigate this issue you can use screen to keep your connection alive. For more information on using screen on the login nodes, see the software section