By default, when submitting a SLURM job as an array, all jobs within the array share the same job name. In the docs (here: https://slurm.schedmd.com/job_array.html), it shows that each job in the array can have its name set separately via scontrol (described under the section "Scontrol Command Use").
Can this be done directly from an sbatch script?
I just created an account because I was trying to do this and I did find a solution.
You can use scontrol to change the name of a job, the syntax is the following:
scontrol update job=<job_id> JobName=<new_name>
You can do this manually, but you can also automatically set the name of the job from within the array job, thus automatically assigning a different name to each job in the array.
I find this useful because I'm mostly running calculations in different directories and if I have one job running much longer than the others I want to be able to quickly retrieve where it's running to see what's going on.
Of course you could set other things as your job name, as you prefer.
In my case, I add the scontrol command to the script I run through the array in order to obtain the following name for each directory: "job_name - directory". The job id and job name can be retrieved from environment variables.
scontrol update job=$SLURM_ARRAY_JOB_ID JobName="$SLURM_JOB_NAME - $folder"
Related
I often run many jobs on slurm. Some finish faster than others. However, it is always hard to keep track which job is which. Can I give custom job names on slurm? If so what is the command on the batch script? Would that show up when I do squeue --me?
The parameter is --job-name (or -J), for instance:
#SBATCH --job-name=exp1_run2
The squeue output will list exp1_run2 for the corresponding job ID under column NAME.
Let's say I have 6233 simulations to run. The commands are generated and stored in a file, one in each line. I would like to use Slurm to schedule and run these commands. However, the MaxArraySize limit is 2000. So I can't use one job array to schedule all of them.
One solution is given here, where we create four separate jobs and use arithmetic indexing into the file, with the last job having a smaller number of tasks to run (233).
Is it possible to do this using one sbatch script with one job ID?
I set ntasks=1 when using job arrays. Do larger ntasks help in such situations?
Update:
Following Damien's solution and examples given here, I ended up with the following line in my bash script:
curID=$(( ${SLURM_ARRAY_TASK_ID} * ${SLURM_NTASKS} + ${SLURM_PROCID} ))
The same can be done using Python (shown in the referenced page). The only difference is that the environment variables should be imported into the script.
Is it possible to do this using one sbatch script with one job ID?
No. That solution will give you multiple job IDs
I set ntasks=1 when using job arrays. Do larger ntasks help in such situations?
Yes, that is a factor that you can leverage.
Each job in the array can spawn multiple tasks (--ntasks=...). In that case, the line number in the command file must be computed from $SLURM_ARRAY_TASK_ID and $SLURM_PROCID, and the program must be started with srun. Each task in a job member of the array will run in parallel. How large the job can be will depend on the MaxJobsize limit defined on the cluster/partition/qos you have access to.
Another option is to chain the tasks inside each job of the array, with a Bash loop (for i in $seq(...) ; do ...; done). In that case, the line number in the command file must be computed from $SLURM_ARRAY_TASK_ID and $i. Each task in a job member of the array will run serially. How large the job can be will depend on the MaxWall limit defined on the cluster/partition/qos you have access to.
Say I want to run a job on the cluster: job1.m
Slurm handles the batch jobs and I'm loading Mathematica to save the output file job1.csv
I submit job1.m and it is sitting in the queue. Now, I edit job1.m to have different variables and parameters, and tell it to save data to job1_edited.csv. Then I re-submit job1.m.
Now I have two batch jobs in the queue.
What will happen to my output files? Will job1.csv be data from the original job1.m file? And will job1_edited.csv be data from the edited file? Or will job1.csv and job1_edited.csv be the same output?
:(
Thanks in advance!
I am assuming job1.m is a Mathematica job, run from inside a Bash submission script. In that case, job1.m is read when the job starts so if it is modified after submission but before job start, the modified version will run. If it is modified after the job starts, the original version will run.
If job1.m is the submission script itself (so you run sbatch job1.m), that script is copied in a spool directory specific to the job so if it is modified after the job is submitted, it still will run the original version.
In any case, it is better, for reproducibility and traceability, to make use of a workflow manager such as Fireworks, or Bosco
I have set of an array job as follows:
sbatch --array=1:100%5 ...
which will limit the number of simultaneously running tasks to 5. The job is now running, and I would like to change this number to 10 (i.e. I wish I'd run sbatch --array=1:100%10 ...).
The documentation on array jobs mentions that you can use scontrol to change options after the job has started. Unfortunately, it's not clear what this option's variable name is, and I don't think it is listed in the documentation of the sbatch command here.
Any pointers well received.
You can change the array throttling limit with the following command:
scontrol update ArrayTaskThrottle=<count> JobId=<jobID>
I have a couple of jobs in the locked jobs queue with the status UserHold. Is there a way to edit the PBS file that launched them? I used qalter before to change the walltime, group or name. This time I want to change the parameters of the aprun call in the submitted PBS file.
Typically speaking you shouldn't do this. The correct procedure would be to delete your job and submit a new one with the new job script.