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Job Scheduling

Priority

For the job scheduling, Slurm assigns each job a priority, which is calculated based on several factors (Multifactor Priority Plugin). Jobs with higher priority, run first. (In principle – the backfill scheduling plugin helps making best use of available resources by filling up resources that are reserved (and thus idle) for large higher priority jobs with small (lower priority) jobs.)

On Albedo, Slurm is configured such, that albedo,  the priority is mainly influenced by the

• the

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• fairshare factor (which is based on the user’s recent use of resources) and
• the QOS' priority factor and
• the time your job waits in the queue

Job size (RAM, cores), partitions and/or associations have no influence; see Fairshare (TODO: Link)), while favoring short jobs (with qos=30min). With longer waiting time in the queue, a job’s priority increases. Job size, partitions or associations are not directly taken into account.

Fairshare

On Albedo all users have the same share of resources, independent of the account used. … TODO…

Sebastian Hinck 

Accounting

TODO...

Sebastian Hinck 

Useful Slurm commands

• sinfo shows existing queues
• scontrol show job <JobID> shows information about specific job
• sstat <JobID> shows resources used by a specific job
• squeue shows information about queues and used nodes
• smap curses-graphic of queues and nodes
• sbatch <script> submits a batch job
• salloc <resources> requests access to compute nodes for interactive use
• scancel <JobID> cancels a batch job
• srun <ressources> <executable> starts a (parallel) code
• sshare and sprio give information on fair share value and job priority

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