I am new to SLURM and I want to run two scripts (each of them take 2 minutes to run) in the same time (parallel) on the same node, same socket, but on different cores. I have a system where one node has 2 sockets, and each socket has 10 cores.
Based on what I have read in one other question (SLURM: How can I run different executables on parallel on the same compute node or in different nodes?) I came up with this code:
#!/bin/bash
#SBATCH -J script
#SBATCH --time=00:05:00
#SBATCH --exclusive
#SBATCH --nodes=1
#SBATCH --ntasks-per-node=2
#SBATCH --cpus-per-task=2
#SBATCH --partition=xeon
#SBATCH --output=OUTPUT.txt
#SBATCH --hint=nomultithread
ml intel
module load openmpi
srun -c 1 --exclusive ./runScript1 &
srun -c 1 --exclusive ./runScript2 &
wait
But when I am typing the squeue --job [jobID] in a repetitive way I see that it takes 4 minutes for the both scripts to execute, which makes me think that they are run sequentially (after the first one is finished, starts the second one).
I have tried also to use taskset to select specific core, but I had some errors.
I am running the script from above using sbatch.
Please tell me if I am assuming wrong or doing something wrong.
It is possible to select a specific core to run on, by including taskset or --cpu-bind option in my code?
Related
I have a heterogeneous cluster, containing either 14-core or 16-core CPUs (28 or 32 threads). I manage job submissions using Slurm. Some requirements:
It doesn't matter which CPU is used for a calculation.
I don't want to specify which CPU a job should go to.
A job should consume all available cores on the CPU (14 or 16).
I want mpirun to handle threading.
To illustrate the peculiarities of the problem, I show a job script that works on the 16-core CPUs:
#!/bin/bash
#SBATCH -J test
#SBATCH -o job.%j.out
#SBATCH -N 1
#SBATCH -n 32
mpirun -np 16 vasp
An example job script that works on the 14-core CPUs is:
#!/bin/bash
#SBATCH -J test
#SBATCH -o job.%j.out
#SBATCH -N 1
#SBATCH -n 28
mpirun -np 14 vasp
The second job script runs on the 16-core CPUs but, unfortunately, the job is about 35% slower than when I request 32 threads as is done in the first script. That's an unacceptable performance loss for my application.
I haven't figured out if there is a good way around this challenge. To me, a solution would be to request a variable number of resources, such as
#SBATCH -n [28-32]
and to tailor the mpirun -np x vasp line accordingly. I haven't found a way to do this, however. Are there any suggestions on how to achieve this directly in Slurm or is there a good workaround?
I tried to use the environmental variable $SLURM_CPUS_ON_NODE, but this variable is only set after the node is selected, so cannot be used in a #SBATCH line.
I also looked at the --constraint flag but this does not seem to give sufficiently granular control over threading requests.
Actually it should work as you want it to by simply specifying that you want a full node:
#!/bin/bash
#SBATCH -J test
#SBATCH -o job.%j.out
#SBATCH -N 1
#SBATCH --exclusive
mpirun vasp
mpirun will start the number of processes as defined in SLURM_TASKS_PER_NODE that will be set by Slurm to the number of tasks that can be created on the node, that is the number of CPUs if you do not request more than one CPU per task.
I'm new here and hope to ask the question correctly.
I'm working on a server that has SLURM as a scheduler. I have many samples on which I have to run a script, but to avoid overlapping the jobs and clogging the cpu I would like to start the jobs one after the other after two hours.
These are the resources I have allocated within the script.
#!/bin/sh
#SBATCH --job-name=bwa
#SBATCH --output=%x_%j.log
#SBATCH --error=%x_%j.err
#SBATCH --mem-per-cpu=2G
#SBATCH -n 128
#SBATCH -N 1
#SBATCH --time=10:00:00
And this is how I run the loop in the folder where the files to be analyzed are present.
for i in *bam; do sbatch pipeline.sh $i; done
How can I add a command that starts the next job after two hours that the previous one is running?
Any advice or suggestion is welcome, both for the resources allocated and for the way of running the jobs.
Thanks in advance to everyone.
I am launching a MPI program through a SBATCH script like this (corresponding to an example script provided by the system administrators):
#! /bin/bash -l
#SBATCH --job-name=test
#SBATCH -o stdout.log
#SBATCH -e stderr.log
#SBATCH --ntasks=160
#SBATCH --time=0-00:10:00
#SBATCH --qos=normal
cd $WORK/
mpirun ./mpiprogram
However, it seems that sometimes more MPI processes are launched than NTASKS. Resulting in sometimes 200 processes when 160 was requested, sometimes different numbers. Note that the nodes have 16 or 20 cores. Some of the worker processes (all pretty much identical in my case) run much slower than the others, perhaps because of swapping. The swapping may be caused by too many processes on one node, causing them to use too much memory.
Should I specify the number of threads to mpirun using $SLURM_NTASKS? Or what is going on here?
I found some very similar questions which helped me arrive at a script which seems to work however I'm still unsure if I fully understand why, hence this question..
My problem (example): On 3 nodes, I want to run 12 tasks on each node (so 36 tasks in total). Also each task uses OpenMP and should use 2 CPUs. In my case a node has 24 CPUs and 64GB memory. My script would be:
#SBATCH --nodes=3
#SBATCH --ntasks=36
#SBATCH --cpus-per-task=2
#SBATCH --mem-per-cpu=2000
export OMP_NUM_THREADS=2
for i in {1..36}; do
srun -N 1 -n 1 ./program input${i} >& out${i} &
done
wait
This seems to work as I require, successively running tasks on a node until all CPUs on that node are in use, and then continuing to run further tasks on the next node until all CPUs are used again, etc..
My question.. I'm not sure if this is actually what it does (?) as I didn't fully understand the man page of srun regarding -n, and i have not used srun before.
Mainly my confusion comes from "-n": In the man page for -n it says "The default is one task per node, ..", so I expected if I use "srun -n 1" that only one task will be run on each node, which doesn't seem to be the case.
Furthermore when i tried e.g. "srun -n 2 ./program" it seems to just run the exact same program twice as two different tasks with no way to use different input files.. which I can't think of why that would ever be useful?
Your setup is correct except that you must use the --exclusive option of srun (which has a different meaning in this case than for sbatch).
As for your remark regarding the usefulness of srun, the behaviour of the program can be changed based on the environment variable $SLURM_TASK_ID, or the rank in case of an MPI program. Your confusion arises from the fact that your program is not written to be parallel (appart from the 2 OMP threads) while srun is meant to start parallel programs, most of the time based on MPI.
An other way is to run all your tasks at once.
since the input and output file depends on the rank, a wrapper is needed
your SLURM script would be
#SBATCH --nodes=3
#SBATCH --ntasks=36
#SBATCH --cpus-per-task=2
#SBATCH --mem-per-cpu=2000
export OMP_NUM_THREADS=2
srun -n 36 ./program.sh
and your wrapper program.sh would be
#!/bin/sh
exec ./program input${SLURM_PROCID} > out${SLURM_PROCID} 2>&1
I am trying to launch a large number of job steps using a batch script. The different steps can be completely different programs and do need exactly one CPU each. First I tried doing this using the --multi-prog argument to srun. Unfortunately, when using all CPUs assigned to my job in this manner, performance degrades massively. The run time increases to almost its serialized value. By undersubscribing I could ameliorate this a little. I couldn't find anything online regarding this problem, so I assumed it to be a configuration problem of the cluster I am using.
So I tried going a different route. I implemented the following script (launched via sbatch my_script.slurm):
#!/bin/bash
#SBATCH -o $HOME/slurm/slurm_out/%j.%N.out
#SBATCH --error=$HOME/slurm/slurm_out/%j.%N.err_out
#SBATCH --get-user-env
#SBATCH -J test
#SBATCH -D $HOME/slurm
#SBATCH --export=NONE
#SBATCH --ntasks=48
NR_PROCS=$(($SLURM_NTASKS))
for PROC in $(seq 0 $(($NR_PROCS-1)));
do
#My call looks like this:
#srun --exclusive -n1 bash $PROJECT/call_shells/call_"$PROC".sh &
srun --exclusive -n1 hostname &
pids[${PROC}]=$! #Save PID of this background process
done
for pid in ${pids[*]};
do
wait ${pid} #Wait on all PIDs, this returns 0 if ANY process fails
done
I am aware, that the --exclusive argument is not really needed in my case. The shell scripts called contain the different binaries and their arguments. The remaining part of my script relies on the fact that all processes have finished hence the wait. I changed the calling line to make it a minimal working example.
At first this seemed to be the solution. Unfortunately when increasing the number of nodes used in my job allocation (for example by increasing --ntasks to a number larger than the number of CPUs per node in my cluster), the script does not work as expected anymore, returning
srun: Warning: can't run 1 processes on 2 nodes, setting nnodes to 1
and continuing using only one node (i.e. 48 CPUs in my case, which go through the job steps as fast as before, all processes on the other node(s) are subsequently killed).
This seems to be the expected behaviour, but I can't really understand it. Why is it that every job step in a given allocation needs to include a minimum number of tasks equal to the number of nodes included in the allocation. I ordinarily really do not care at all about the number of nodes used in my allocation.
How can I implement my batch script, so it can be used on multiple nodes reliably?
Found it! The nomenclature and the many command line options to slurm confused me. The solution is given by
#!/bin/bash
#SBATCH -o $HOME/slurm/slurm_out/%j.%N.out
#SBATCH --error=$HOME/slurm/slurm_out/%j.%N.err_out
#SBATCH --get-user-env
#SBATCH -J test
#SBATCH -D $HOME/slurm
#SBATCH --export=NONE
#SBATCH --ntasks=48
NR_PROCS=$(($SLURM_NTASKS))
for PROC in $(seq 0 $(($NR_PROCS-1)));
do
#My call looks like this:
#srun --exclusive -N1 -n1 bash $PROJECT/call_shells/call_"$PROC".sh &
srun --exclusive -N1 -n1 hostname &
pids[${PROC}]=$! #Save PID of this background process
done
for pid in ${pids[*]};
do
wait ${pid} #Wait on all PIDs, this returns 0 if ANY process fails
done
This specifies to run the job on exactly one node incorporating a single task only.