Interactive Sessions
Overview
Interactive sessions allow users to directly interact with compute nodes on the supercomputer, facilitating step-by-step experimentation, iterative testing, or interactive tasks. You will especially want to use an interactive session for tasks such as creating python environments, bulk deleting/renaming files, and other light work.
In fact, we have an entire partition of resources set aside for immediate allocation to users wanting to do these tasks, lightwork; no need to wait in line for these kinds of tasks!
Starting an Interactive Session
To launch a basic interactive compute session, log in and execute:
interactive
interactive is a shortcut for salloc -c 1 -p htc -q public -t 0-4 which allocates one CPU core for 4 hours in the htc partition. This requests the first-available core among the dedicated compute nodes to be allocated for your job.
For light work, you can get a core even more quickly with interactive -p lightwork
After your session begins, you can immediately start working directly from your terminal window.
Customizing Interactive Session Resources
interactive is a convenient shortcut, but for more specific resource allocations and durations, use salloc directly from the login node. You can see the full list of available salloc options from the official salloc documentation. More examples can be found in the Requesting Resources page.
# Launch an interactive session requesting 8 CPU cores on 1 node for 6 hours
salloc -p public -c 8 -N 1 -t 0-6:00
# Specify a session duration explicitly (`days-hours:minutes` format):
salloc -p public -t 1-12:00