Interactive Job Submission on the Flood2 Cluster

Batch processing is the preferred method to use on a shared cluster. However, there are times when a user needs to run interactive tools, such as idl, matlab, rstudio, etc. To run these interactive processes you can request a dedicated compute node for that job. The following example will show you how to request a compute node for an interactive job process:

Submit the job:

[jreese12@flood2 ~]$ qsub -I

qsub: waiting for job 7.flood2 to start

qsub: job 7.flood2 ready

[jreese12@compute-003 ~]$

This will result in a new prompt on the free compute node, and you can now submit your workflow:

[jreese12@compute-003 ~]$

Once you are finished you can simply exit the node:

[jreese12@compute-003 ~]$ exit

logout

qsub: job 7.flood2 completed

If you want to start a graphical program on a compute node (ie. matlab) you will need to use the -X option with qsub and make sure you are connected to the headnode via ssh -X

For example (from a linux desktop)

$ ssh -X jreese12@flood2.umd.edu

[jreese12@flood2 ~]$ qsub -I -X

qsub: waiting for job 1021.flood2 to start

qsub: job 1021.flood2 ready

[jreese12@compute-002 ~]$ matlab

MATLAB is selecting SOFTWARE OPENGL rendering.