Oscar is a shared machine used by hundreds of users at once. User requests are called jobs. A job is the combination of the resource requested and the program you want to run on the compute nodes of the Oscar cluster. On Oscar, Slurm is used to schedule and manage jobs.
Jobs can be run on Oscar in two different ways:
- Interactive jobs allow the user to interact with programs (e.g., by entering input manually, using a GUI) while they are running. However, if your connection to the system is interrupted, the job will abort. Small jobs with short run times and jobs that require the use of a GUI are best-suited for running interactively.
- Batch jobs allow you to submit a script that tells the cluster how to run your program. Your program can run for long periods of time in the background, so you don't need to be connected to Oscar. The output of your program is continuously written to an output file that you can view both during and after your program runs.
Jobs are scheduled to run on the cluster according to your account priority and the resources you request (i.e., cores, memory, and runtime). In general, the fewer resources you request, the less time your job will spend waiting in the queue.