Run interactively¶

Here’s a simplified workflow of booking a node.

Booking a node might be suitable if you want to test and verify your code in a parallell environment, or when the code is not time consuming but frequent adjustment is needed.

Compute nodes can be booked from the queue system for interactive use. This means that you can run your program similar to how you run it on a local computer through terminal.

Booking an interactive node can be useful when you want to test, verify or debug your code in a parallell environment. It’s also suitable when the program is not time consuming but is in need of frequent adjustment. For a large scale program we recommend Queueing jobs instead, since waiting for an interactive node booked with large amount of run time can take a lot of time.

The command to book an interactive node is interactive

Example to book a node using interactive¶

$ interactive --nodes=1 -t 1:00:00 -A <project> -p <partition>
salloc: Granted job allocation 257481
salloc: Waiting for resource configuration
salloc: Nodes n414 are ready for job
[@n414 ~]$

The above command would then book one node and automatically log into that specific node. Depending on how busy the supercomputer is, it might take a while before the interactive node is booked. The -A should be the time allocation you are a part of. The -A flag must be specified, or the command will receive an error.

Job submit/allocate failed: Invalid partition or qos specification

You can check the time allocations you are a member of with

projinfo [options]

You can also login to the interactive compute node from a separate window using salloc, which books a node. The name for the booked node is written with the output of the command. After which you can use jobsh with which you can log into the node.

Example to book a node using salloc¶

$ salloc --nodes=1 -t 1:00:00 -A <project> -p <partition>
salloc: Granted job allocation 257481
salloc: Waiting for resource configuration
salloc: Nodes n414 are ready for job

After this you can login to the node using...

[@arrhenius1 ~]$ jobsh n414
[@n414 ~]$