Testing With Graphics
If you need to use graphics while testing your code on a Niagara compute node, e.g. when using a debugger such as DDT or DDD, you have the following options.
Use the debugjob command
You can use the
debugjob command, which automatically provides X-forwarding support.
$ ssh niagara.scinet.utoronto.ca -X USER@nia-login07:~$ debugjob debugjob: Requesting 1 nodes for 60 minutes salloc: Granted job allocation 189857 salloc: Waiting for resource configuration salloc: Nodes nia0030 are ready for job [USER@nia1265 ~]$
Use the regular queue
debugjob is not suitable for your case due to the limitations either on time or resources (see Testing and Debugging), then you can use the salloc command with the --x11 option. For instance
$ ssh -Y niagara.scinet.utoronto.ca USER@nia-login07:~$ salloc --nodes 5 --time=2:00:00 --x11 salloc: Granted job allocation 141862 salloc: Waiting for resource configuration salloc: Nodes nia[1265-1271] are ready for job [USER@nia1265 ~]$ [USER@nia1265 ~]$ xclock ## just an example to test the graphics, a clock should pop up, close it to exit [USER@nia1265 ~]$ module load ddt ## load corresponding modules, eg. for DDT [USER@nia1265 ~]$ ddt ## launch DDT, the GUI should appear in your screen
- If you are using SSH from a Windows machine, you need to have an X-server, a good option is to use MobaXterm, that already brings an X-server included. See the Windows SSH entry for other options.
- In some case you can substitute -Y by -X, but this may cause the X display to unexpectedly be disconnected.