Batch jobs allow users to execute tasks without direct interaction with the computing environment. These jobs are written in scripts, which include commands for the job's execution and resource requests which will be interpreted by the cluster scheduler which is Slurm in our case, and are submitted to the job scheduling system.
### BATCH directives
BATCH directives are special comments at the top of a batch job script that provide the scheduler (like Slurm) with instructions about how to handle the job. These include resource requests (such as the number of nodes, CPUs per task, amount of memory, and job runtime) and other job-related settings. We will introduce some common and more advanced directives in this page's example scripts.
BATCH directives are essentially instructions embedded at the beginning of a batch job script and are interpreted by the scheduler (like Slurm in our case). These lines are prefixed with `#SBATCH` for Slurm and inform the scheduler about the resources needed for the job and any other execution preferences.
Here are a list of common directives: <br>
**Note:** These bullets are just for a better basic understanding on the topic. Complete examples and line-by-line explanations are provided further down on this page.
*`#SBATCH --nodes=1`: Requests a specific number of nodes.
*`#SBATCH --ntasks-per-node=1`: Defines the number of tasks to run on each node.
*`#SBATCH --mem=4G`: Specifies the amount of memory required.
*`#SBATCH --time=01:00:00`: Sets the maximum runtime (hh:mm:ss).
*`#SBATCH --partition=standard`: Specifies the queue/partition where the job should be submitted.
*`#SBATCH --output=result.txt`: Directs the job's output to a specific file.
