Contents
Slurm Pilot project for Biwi
- The following information is an abbreviated How-To with specific information for the pilot cluster
Our official documentation for slurm is the Computing wiki article, you need to read this as well.
- Please bear in mind the final documentation is meant to be the above article. It will be extended with your feedback valid for all slurm users and a specific section or additional page concerning only Biwi.
The goal of this pilot is to have a documentation to enable SGE users to migrate their jobs to Slurm. This also means the section Accouns and limits has only informative purpose at the moment.
Pilot-specific information
Involved machines are
biwirender01 for CPU computing
biwirender03 for GPU-computing
All available GPU partitions are overlayed on biwirender03. They will be available on different nodes in the final cluster.
![/!\](/static/comp/img/alert.png "/!\"){kind=small}
long partitions are not yet implemented in the pilot!
Initialising slurm
All slurm command read the cluster configuration from the environment variable SLURM_CONF, so it needs to be set:
export SLURM_CONF=/home/sladmcvl/slurm/slurm.conf
If you're interested, feel free to have a look at the configuration, feedback is welcome!
Available partitions
The equivalent to SGE's queues is called partitions in slurm.
sinfo shows all available partitions:
sinfo
PARTITION AVAIL TIMELIMIT NODES STATE NODELIST cpu.medium.normal up 2-00:00:00 1 idle biwirender01 gpu.low.normal up 2-00:00:00 1 idle biwirender03 gpu.medium.normal up 2-00:00:00 1 idle biwirender03 gpu.medium.long up 5-00:00:00 1 idle biwirender03 gpu.high.normal up 2-00:00:00 1 idle biwirender03 gpu.high.long up 5-00:00:00 1 idle biwirender03 gpu.debug up 6:00:00 1 idle biwirender03 gpu.mon up 6:00:00 1 idle biwirender03
Only interactive partitions gpu.debug and gpu.monitor can and should be specified (see below). The scheduler decides in which partition to put a job based on the resources requested by it.
Interactive jobs
For testing purposes a job with an interactive session with 1 GPU can be started:
srun --time 10 --partition=gpu.debug --gres=gpu:1 --pty bash -i
Such jobs are placed in gpu.debug by the scheduler
To monitor a running job, an interactive session can be started with explicitly selecting the monitoring partition. The node where the batch job is running needs to be specified as well:
srun --time 10 --partition=gpu.mon --nodelist=biwirender03 --pty bash -i
- Allocating GPU resources is prohibited for such interactive jobs
- It may be possible to attach an interactive session to an already running job, which will make the above obsolete. This is still under investigation at the moment.
Allocating resources
GPUs
For a job to have access to a GPU, GPU resources need to be requested with the option --gres=gpu:<n>
Here's the sample job submission script primes_1GPU.sh requesting 1 GPU:
# #SBATCH --mail-type=ALL #SBATCH --gres=gpu:1 #SBATCH --output=log/%j.out export LOGFILE=`pwd`/log/$SLURM_JOB_ID.out # env | grep SLURM_ #Uncomment this line to show environment variables set by slurm for a job # # binary to execute codebin/primes $1 echo "" echo "Job statistics: " sstat -j $SLURM_JOB_ID --format=JobID,AveVMSize%15,MaxRSS%15,AveCPU%15 echo "" exit 0;
- Make sure the directory wherein to store logfiles exists before submitting a job.
Please keep the environment variable LOGFILE, it is used in the scheduler's epilog script to append information to your logfile after your job ended (and therefore doesn't have access to $SLURM_JOB_ID anymore).
slurm also sets CUDA_VISIBLE_DEVICES. See the section GPU jobs in the main slurm article.
Memory
If you omit the --mem option, the default of 30G/GPU memory and 3CPUs/GPU will be allocated to your job, which will make the scheduler choose gpu.medium.normal:
sbatch primes_1GPU.sh sbatch: GRES requested : gpu:1 sbatch: GPUs requested : 1 sbatch: Requested Memory : --- sbatch: CPUs requested : --- sbatch: Your job is a gpu job. Submitted batch job 133
squeue --Format jobarrayid:8,partition:20,reasonlist:20,username:10,tres-alloc:45,timeused:10
JOBID PARTITION NODELIST(REASON) USER TRES_ALLOC TIME 133 gpu.medium.normal biwirender03 testuser cpu=3,mem=30G,node=1,billing=3,gres/gpu=1 0:02
An explicit --mem option selects the partition as follows:
--mem |
Partition |
< 30G |
gpu.low.normal |
30G - 50G |
gpu.medium.normal |
>50G - 70G |
gpu.high.normal |
>70G |
not allowed |
For example with:
sbatch --mem=50G primes_2GPU.sh
the above squeue command shows:
JOBID PARTITION NODELIST(REASON) USER TRES_ALLOC TIME 136 gpu.high.normal biwirender03 testuser cpu=6,mem=100G,node=1,billing=6,gres/gpu=2 0:28
Accounts and limits
In slurm lingo an account is equivalent to a user group. The following accounts are configured for users to be added to:
sacctmgr show account
Account Descr Org
---------- -------------------- --------------------
deadconf deadline_conference biwi
deadline deadline biwi
isg isg isg
root default root account root
staff staff biwi
student student biwiAccounts isg and root are not accessible to Biwi
GPU limits are stored in so-called QOS, each account is associated with the QOS we want to apply to it. Limits apply to all users added to an account.
sacctmgr show assoc format=account%15,user%15,partition%15,maxjobs%8,qos%15,defaultqos%15
Account User Partition MaxJobs QOS Def QOS
--------------- --------------- --------------- -------- --------------- ---------------
root normal
root root normal
deadconf gpu_4 gpu_4
deadline gpu_3 gpu_3
deadline ........ gpu_3 gpu_3
isg normal
isg sladmall normal
staff gpu_2 gpu_2
staff ........ gpu_2 gpu_2
staff ........ gpu_2 gpu_2
staff ........ gpu_2 gpu_2
staff ........ gpu_2 gpu_2
staff ........ gpu_2 gpu_2
student gpu_1 gpu_1The QOS' gpu_x only contain a limit for the amount of GPUs per user:
sacctmgr show qos format=name%15,maxtrespu%30
Name MaxTRESPU
--------------- ------------------------------
normal
gpu_1 gres/gpu=1
gpu_2 gres/gpu=2
gpu_3 gres/gpu=3
gpu_4 gres/gpu=4
gpu_5 gres/gpu=5
gpu_6 gres/gpu=6Users with administrative privileges can move a user between accounts deadline or deadconf.
List associations of testuser:
sacctmgr show assoc where user=testuser format=account%15,user%15,partition%15,maxjobs%8,qos%15,defaultqos%15
Account User Partition MaxJobs QOS Def QOS
--------------- --------------- --------------- -------- --------------- ---------------
deadline testuser gpu_3 gpu_3Move testuser from deadline to staff:
/home/sladmcvl/slurm/change_account_of_user.sh testuser deadline staff
List associations of testuser again:
sacctmgr show assoc where user=testuser format=account%15,user%15,partition%15,maxjobs%8,qos%15,defaultqos%15
Account User Partition MaxJobs QOS Def QOS
--------------- --------------- --------------- -------- --------------- ---------------
staff testuser gpu_2 gpu_2Accounts with administrative privileges can be shown with:
sacctmgr show user format=user%15,defaultaccount%15,admin%15'
Last words
Have fun using SLURM for your jobs!