Options for running interactively on the compute nodes:
Don't just submit the job, but also wait for it to start and connect
stdinto the current terminal.
Enable X forwarding, so programs using a GUI can be used during the session (provided you have X forwarding to your workstation set up)
Pass the current environment to the interactive batch job
- To leave an interactive batch session, type
exitat the command prompt.
Certain tasks need user interaction - such as debugging and some GUI-based applications. However the HPC clusters rely on batch job scheduling to efficiently allocate resources. Interactive batch jobs allow these apparently conflicting requirements to be met.
When you start an interactive batch job the command prompt is not immediately returned. Instead, you wait until the resource is available when the prompt is returned and you are on a compute node and in a batch job - much like the process of logging in to a host with
ssh. To end the session, type '
exit', again just like the process of logging in and out with
To use any GUI-based program within the interactive batch session you will need to extend X forwarding with the
-X option or directive. This of course still relies on you having X forwarding at your login session - try running '
xterm' before starting the interactive to verify that this is working correctly.
You can request resources for an interactive batch session just as you would for any other job, for example to request 4 processors with 4GB memory for 2 hours:
If you do not request resources you will get 1 CPU and 2GB of memory, for 1 hour.
Your interactive session will start in your home directory, you can jump to the directory you submitted from with: