===== Slurm HPC Scheduler =====

Slurm is a highly configurable open-source workload manager. In its simplest configuration, it can be installed and configured in a few minutes.  Use of optional plugins provides the functionality needed to satisfy the needs of demanding HPC centers. More complex configurations rely upon a database for archiving accounting records, managing resource limits, and supporting sophisticated scheduling algorithms.

==== Architecture ====
{{:slurm:slurm_arch.gif?nolink&800|}}

As depicted in the above picture, Slurm consists of a worker daemon (slurmd) running on each compute node and a central controller daemon (slurmctld) running on a management node (with optional fail-over twin). The slurmd daemons provide fault-tolerant hierarchical communications.

==== Features, Generic consumable Resources and Partitions ====

Every cluster will have their specific features (--constraint), generic consumable resources (--gres) and partitions.

  * **[[eemcs-hpc:specifics|EEMCS-HPC features, resources and partitions]]**

==== Submitting Jobs ====

Before submitting jobs please note the maximum number of jobs and maximum number of job steps per job which can be scheduled.
These numbers can be obtained using the **//scontrol show config//** command on the **headnode**.

**[[slurm:sbatch|sbatch]]** is used to submit a job script for later execution. The script will typically contain one task or (if required) multiple **[[slurm:srun|srun]]** commands to launch parallel tasks.
See the **[[slurm:sbatch|sbatch]]** and **[[slurm:srun|srun]]** wiki page for more details.

=== Interactive Jobs ===

It is possible to request for an interactive job, within this job you can execute small experiments. Use this only for a short time (max 1 hour).
See the **[[slurm:srun|srun]]** wiki page for more details.

==== Monitoring Slurm ====

To monitor the jobs and progress you can use the corresponding slurm dashboard page or the available command line tools like **squeue** or **scontrol**.

  * **[[http://korenvliet.ewi.utwente.nl/slurm/|EEMCS-HPC slurm dashboard page]]**