Slurm Batch system usage

This is introduction to T3 Slurm configuration - a modern job scheduler for Linux clusters.

Please use User Interface Nodes t3ui01-03 mostly for development and small quick tests.

For intensive computational work one should use Compute Nodes. There are two types of Compute Nodes in T3 Slurm - Worker Nodes for CPU usage and GPU machines. All new hardware is equipped with 256GB of RAM and 10GbE network:

Compute Node	Processor Type	Computing Resources: Cores/GPUs
t3gpu0[1-2]	Intel Xeon E5-2630 v4 (2.20GHz)	8 * GeForce GTX 1080 Ti
t3ui01-03 - login node	Intel Xeon E5-2697 (2.30GH)	72
t3wn30-36,38-39	Intel Xeon E5-2670 (2.6 GHz)	16
t3wn41-43,45-48	AMD Opteron 6272 (2.1GHz)	32
t3wn51-59	Intel Xeon E5-2698 (2.30GHz)	64
t3wn60-63	Intel Xeon Gold 6148 (2.40GHz)	80

Access to the Compute Nodes is controlled by Slurm.
Currently Maximum number of CPU jobs each user is allowed to run is 500 (it's about 40% of CPU resources).
There are four partitions (similar to SGE queues) implemented. Two for CPU and 2 for GPU usage:

• quick for CPU short jobs; default time is 30 min, max - 1 hour
• wn for CPU longer jobs
• qgpu for short GPU jobs; default time is 30 min, max - 1 hour and 1 GPU/user
• gpu for GPU resources; max 15 GPUs/user

Here is few useful commands start to work with Slurm:

sinfo           # monitor nodes and partitions queue information
sbatch          # submit a batch script 
squeue          # view information about jobs in the scheduling queue
scontrol show jobid -dd JobID  #  helpful for job troubleshooting
sstat -j JobID   # information about running  jobs (or specific job JobID) 
scancel -j JobID   # abort job JobID
scancel -n JobID    # deletes all jobs with job name JobID
sprio -l        #  priority of your jobs
sshare -a       # share information about all users
sacct -j  --format=JobID,JobName,MaxRSS,Elapsed #  information on completed jobs (or specific job JobID)
sacct --helpformat # see format options for sacct

To submit job to the wn partition issue: sbatch -p wn --account=t3 job.sh

One might create a shell script with a set of all directives starting with #SBATCH string like in the following examples.

GPU Example

CPU Example

CPU Example for using multiple processors (threads) on a single physical computer

One can check Slurm configuration (information about Nodes and Partitions, etc.) from /etc/slurm/slurm.conf

Slurm itself calculates priorities of jobs taking into account
- Age of Job: the job has been waiting in queue
- FairShare: past of the cluster usage by the user
- Job Size: resources request CPU, Memeory

So that it's useful to declare time resource in submission script (the less required the higher priority) with time option like --time=...