All jobs on the general purpose cluster request resources via SLURM. SLURM, is open source software that allocates resources to users for their computations, provides a framework for starting, executing and monitoring compute jobs, and arbitrates contention for resources by managing a queue of pending work. SLURM is widely used in the high performance computing (HPC) landscape and it is likely you will encounter it outside of our systems.
General Purpose Computing
All resources on the general purpose cluster are submitted using the SLURM scheduler. For more information, please read the Frequently asked Questions. Jobs can be submitted from the following headnodes:
| head.arcc.albany.edu |
| headnode7.rit.albany.edu |
Or from the large memory machine:
| lmm.rit.albany.edu |
Resource information
All users have access to the "batch" partition for general purpose computing.
$ sinfo -p batch -o "%n, %c, %m" | sort PARTITION, HOSTNAMES, CPUS, MEMORY batch*, rhea-01, 24, 64133 batch*, rhea-02, 24, 64133 batch*, rhea-03, 24, 64133 batch*, rhea-04, 32, 96411 batch*, rhea-05, 32, 96411 batch*, rhea-06, 32, 96411 batch*, rhea-07, 40, 128619 batch*, rhea-08, 40, 128619 batch*, rhea-09, 48, 257627 batch*, rhea-10, 48, 257566 batch*, uagc12-01, 12, 64166 batch*, uagc12-02, 12, 64166 batch*, uagc12-03, 12, 64166 batch*, uagc12-04, 12, 64166 batch*, uagc12-05, 32, 128703 batch*, uagc19-01, 20, 94956 batch*, uagc19-02, 20, 94956 batch*, uagc19-03, 20, 94956 batch*, uagc19-04, 20, 94956 batch*, uagc19-05, 20, 94956 batch*, uagc19-06, 20, 94956
Frequently asked questions
SLURM documentation can be found at the SLURM website (https://slurm.schedmd.com); but below are answers to frequently asked questions which demonstrate several useful SLURM commands.
How can I view the current status, or resources available, of batch nodes?
sinfo is commonly used to few the status of a give cluster or node, or how many resources are available to schedule.
$ sinfo -p batch -o "%n, %a, %C, %e, %O" HOSTNAMES, AVAIL, CPUS(A/I/O/T), FREE_MEM, CPU_LOAD rhea-01, up, 1/23/0/24, 47457, 1.02 rhea-07, up, 8/32/0/40, 106761, 8.03 rhea-08, up, 8/32/0/40, 111833, 8.07 rhea-10, up, 8/40/0/48, 238471, 8.01 rhea-09, up, 48/0/0/48, 243033, 45.69 rhea-04, up, 32/0/0/32, 50843, 20.25 rhea-02, up, 0/24/0/24, 61907, 0.00 rhea-03, up, 0/24/0/24, 61530, 0.00 rhea-05, up, 0/32/0/32, 94105, 0.02 rhea-06, up, 0/32/0/32, 93951, 0.00 uagc12-01, up, 0/12/0/12, 62691, 0.00 uagc12-02, up, 0/12/0/12, 62672, 0.00 uagc12-03, up, 0/12/0/12, 62867, 0.05 uagc12-04, up, 0/12/0/12, 62862, 0.00 uagc12-05, up, 0/32/0/32, 127211, 0.00 uagc19-01, up, 0/20/0/20, 93496, 0.03 uagc19-02, up, 0/20/0/20, 93489, 0.00 uagc19-03, up, 0/20/0/20, 93482, 0.00 uagc19-04, up, 0/20/0/20, 93570, 0.00 uagc19-05, up, 0/20/0/20, 93579, 0.00 uagc19-06, up, 0/20/0/20, 93583, 0.00
How can I view jobs currently running, and waiting in queue?
squeue will show jobs currently waiting in the queue or running, for all partitions that you have access to.
$ squeue
JOBID PARTITION NAME USER ST TIME NODES NODELIST(REASON)
140574 batch g.slurm [netid] PD 0:00 1 (Resources)
140486 batch g.slurm [netid] R 21:53:54 1 rhea-04
140290 batch run.sh [netid] R 2-19:09:35 1 rhea-01
140216 batch shell1_5 [netid] R 3-08:48:18 1 rhea-09
135093 batch g.sh [netid] R 28-19:56:31 1 rhea-08
135087 batch g.sh [netid] R 28-20:43:49 1 rhea-10
135090 batch g.sh [netid] R 28-20:49:42 1 rhea-07
At the time this command was run, there were 7 jobs running or waiting in queue. JOBID 140574 is waiting in the queue due to inadequate available resources, while the other jobs have been running for a few days.
How can I view the resources requested for an active job?
scontrol show job [jobid] will generate a report with information about how a job was scheduled.
Note that once a job is completed, this report can no longer be generated via scontrol. See How do I view the resources used by my job? for accessing similar information upon job completion.
$ scontrol show job ###### JobId=###### JobName=g.slurm UserId=[netid](52639) GroupId=faculty(972) MCS_label=N/A Priority=1 Nice=0 Account=rit QOS=normal JobState=PENDING Reason=Resources Dependency=(null) Requeue=1 Restarts=0 BatchFlag=1 Reboot=0 ExitCode=0:0 RunTime=00:00:00 TimeLimit=14-00:00:00 TimeMin=N/A SubmitTime=2019-02-13T07:48:25 EligibleTime=2019-02-13T07:48:25 StartTime=2019-02-14T11:53:10 EndTime=2019-02-28T11:53:10 Deadline=N/A PreemptTime=None SuspendTime=None SecsPreSuspend=0 LastSchedEval=2019-02-13T08:42:58 Partition=batch AllocNode:Sid=headnode7:86819 ReqNodeList=(null) ExcNodeList=(null) NodeList=(null) NumNodes=1 NumCPUs=32 NumTasks=1 CPUs/Task=32 ReqB:S:C:T=0:0:*:* TRES=cpu=32,mem=87.50G,node=1 Socks/Node=* NtasksPerN:B:S:C=0:0:*:* CoreSpec=* MinCPUsNode=32 MinMemoryCPU=2800M MinTmpDiskNode=0 Features=avx2 DelayBoot=00:00:00 Gres=(null) Reservation=(null) OverSubscribe=OK Contiguous=0 Licenses=(null) Network=(null) Command=/path/to/command/ WorkDir=/path/to/workdir/ StdErr=/path/to/stderr/ StdIn=/dev/null StdOut=/path/to/stdout/ Power=
Here, the job requested 32 CPUs on one node, with 87.5GB of memory, at 2019-02-13T07:48:25, with a constraint of Features=avx2.
NumNodes=1 NumCPUs=32 NumTasks=1 CPUs/Task=32 ReqB:S:C:T=0:0:*:*
TRES=cpu=32,mem=87.50G,node=1
Features=avx2
How can I view what restrictions are imposed on jobs?
$ scontrol show partition batch PartitionName=batch AllowGroups=ALL AllowAccounts=ALL AllowQos=ALL AllocNodes=ALL Default=YES QoS=N/A DefaultTime=NONE DisableRootJobs=NO ExclusiveUser=NO GraceTime=0 Hidden=NO MaxNodes=3 MaxTime=14-00:00:00 MinNodes=1 LLN=NO MaxCPUsPerNode=UNLIMITED Nodes=rhea-[01-10],uagc19-[01-06],uagc12-[01-05] PriorityJobFactor=1 PriorityTier=10 RootOnly=NO ReqResv=NO OverSubscribe=FORCE:1 OverTimeLimit=NONE PreemptMode=OFF State=UP TotalCPUs=544 TotalNodes=21 SelectTypeParameters=NONE DefMemPerNode=UNLIMITED MaxMemPerNode=UNLIMITED
batch has some important restrictions. A job can only request 3 nodes and will run for 14 days before being automatically terminated. If you need an exception to this rule, please contact arcc@albany.edu
How do I schedule a non-interactive job?
There are many ways to schedule jobs via slurm. For non-interactive jobs, we recommend using sbatch with a shell script that runs your script. We will use #SBATCH commands to allocate the appropriate resources required for our script. Below is an example workflow of how to submit a python script via sbatch to batch.
First ssh into head.arcc.albany.edu. On windows, you can use an ssh client such as PuTTY, on mac, simply use the terminal. Replace [netid] below with your username and type in your password at the prompt. You will not see your password, but it is being typed.
$ ssh [netid]@head.arcc.albany.edu Warning: Permanently added the ECDSA host key for IP address '169.226.65.82' to the list of known hosts. [netid]@head.arcc.albany.edu's password: Warning: No xauth data; using fake authentication data for X11 forwarding. Last login: Wed Jan 30 13:49:20 2019 from lmm.rit.albany.edu ================================================================================ This University at Albany computer system is reserved for authorized use only. http://www.albany.edu/its/authorizeduse.htm Headnodes: head.arcc.albany.edu headnode7.rit.albany.edu headnode.rit.albany.edu - LEGACY SUPPORT General Purpose Computing: lmm.rit.albany.edu - Large memory x2go headnode: eagle.arcc.albany.edu Questions / Assistance - arcc@albany.edu ================================================================================Next, change directories to /network/rit/misc/software/examples/slurm/
$ cd /network/rit/misc/software/examples/slurm/
/network/rit/misc/software/examples/slurm/run.sh contains #SBATCH commands that will request the appropriate amount of resources for our python code, then execute the code.
$ more run.sh #!/bin/bash #SBATCH -p batch #SBATCH --cpus-per-task=4 #SBATCH --mem-per-cpu=100 #SBATCH --mail-type=ALL #SBATCH --mail-user=%u@albany.edu #SBATCH -o /network/rit/home/%u/example-slurm-%j.out # Now, run the python script /network/rit/misc/software/examples/slurm/simple_multiprocessing.py
--cpus-per-task=4 tells SLURM how many cores we want to allocate on one node
--mem-per-cpu=100 tells SLURM how much memory to allocate per core (see also --mem)
In total, we are requesting 4 cores and 400MB of memory for this simple python code
To submit the job, we simply run sbatch run.sh. Keep note of the Job ID that is output to the terminal, it will be different that what is shown below.
$ sbatch run.sh Submitted batch job 140584
Note that you can use squeue to view the job status
The job will output a file to your home directory called ~/example-slurm-[jobid].out. We will view it using the "more" command. You should see output similar to below.
$ more ~/example-slurm-140584.out USER [netid] was granted 4 cores and 100 MB per node on [hostname]. The job is current running with job # [jobid] Process D waiting 3 seconds Process D Finished. Process C waiting 1 seconds Process C Finished. Process E waiting 4 seconds Process E Finished. Process A waiting 5 seconds Process A Finished. Process B waiting 2 seconds Process B Finished. Process F waiting 5 seconds Process F Finished.
- Congratulations, you just ran your first job on the cluster!
How do I schedule an interactive job?
An "interactive" job means that you will have access to a terminal so that you can run "interactively" on the cluster. To achieve this, we will use srun. Interactive sessions are useful for debugging code, or making sure certain software compiles correctly.
First ssh into head.arcc.albany.edu. On windows, you can use an ssh client such as PuTTY, on mac, simply use the terminal. Replace [netid] below with your username and type in your password at the prompt. You will not see your password, but it is being typed.
$ ssh [netid]@head.arcc.albany.edu Warning: Permanently added the ECDSA host key for IP address '169.226.65.82' to the list of known hosts. [netid]@head.arcc.albany.edu's password: Warning: No xauth data; using fake authentication data for X11 forwarding. Last login: Wed Jan 30 13:49:20 2019 from lmm.rit.albany.edu ================================================================================ This University at Albany computer system is reserved for authorized use only. http://www.albany.edu/its/authorizeduse.htm Headnodes: head.arcc.albany.edu headnode7.rit.albany.edu headnode.rit.albany.edu - LEGACY SUPPORT General Purpose Computing: lmm.rit.albany.edu - Large memory x2go headnode: eagle.arcc.albany.edu Questions / Assistance - arcc@albany.edu ================================================================================Next, allocate resources on the cluster for your interactive session. We will request a session that will last for 1 hour, with 4 cpus and 400 mb of memory. Note your job number will be different
$ srun --partition=batch --nodes=1 --time=01:00:00 --cpus-per-task=4 --mem=400 --pty $SHELL -i $ hostname uagc12-01.arcc.albany.edu
Now we are running a terminal session on a specific node on the cluster. Notice in step 2, that the hostname command output a host other than head.arcc.albany.edu.
$ cd /network/rit/misc/software/examples/slurm/ $ ./simple_multiprocessing.py USER ns742711 was granted 4 cores and None MB per node on uagc12-01. The job is current running with job # 140590 Process D waiting 3 seconds Process D Finished. Process A waiting 5 seconds Process A Finished. Process C waiting 1 seconds Process C Finished. Process E waiting 4 seconds Process E Finished. Process B waiting 2 seconds Process B Finished. Process F waiting 5 seconds Process F Finished.
When you are finished, type exit and then use scancel to relinquish the allocation
$ exit $ scancel 140590 salloc: Job allocation 140590 has been revoked.
How do I view the resources used by my job?
sacct is useful to view accounting information on completed jobs. Read the documentation for all output fields.
$ sacct -u ns742711 -j 139907 -o "Nodelist, JobID, AllocNodes, AllocTRES%30, MaxVMSize, MaxVMSizeTask, AveVMSize, TotalCPU, Elapsed"
NodeList JobID AllocNodes AllocTRES MaxVMSize MaxVMSizeTask AveVMSize TotalCPU Elapsed
--------------- ------------ ---------- ------------------------------ ---------- -------------- ---------- ---------- ----------
rhea-09 139907 1 cpu=24,mem=60000M,energy=1844+ 13-00:45:+ 14:50:14
rhea-09 139907.batch 1 cpu=24,mem=60000M,node=1 54764616K 0 54506520K 13-00:45:+ 14:50:1
This job ran on rhea-09, and it's max memory size was ~52 GB. That that I requested 60000MB, so I could refine this job to request slightly less memory. It ran for 14:50:14 and used about 350 CPU hours.
Can I restrict my job to a certain CPU architecture?
Yes! Use the --constraint flag in #SBATCH. To few available architecture on individual nodes use scontrol show node
$ scontrol show node uagc19-06 NodeName=uagc19-06 Arch=x86_64 CoresPerSocket=10 CPUAlloc=0 CPUErr=0 CPUTot=20 CPULoad=0.00 AvailableFeatures=intel,skylake,sse4_2,avx,avx2,avx512 ActiveFeatures=intel,skylake,sse4_2,avx,avx2,avx512 Gres=(null) NodeAddr=uagc19-06.arcc.albany.edu NodeHostName=uagc19-06 Version=17.11 OS=Linux 4.14.35-1844.0.7.el7uek.x86_64 #2 SMP Wed Dec 12 19:48:02 PST 2018 RealMemory=94956 AllocMem=0 FreeMem=93582 Sockets=2 Boards=1 State=IDLE ThreadsPerCore=1 TmpDisk=4086 Weight=256 Owner=N/A MCS_label=N/A Partitions=batch BootTime=2019-02-11T10:15:23 SlurmdStartTime=2019-02-11T10:15:48 CfgTRES=cpu=20,mem=94956M,billing=20 AllocTRES= CapWatts=n/a CurrentWatts=0 LowestJoules=0 ConsumedJoules=0 ExtSensorsJoules=n/s ExtSensorsWatts=0 ExtSensorsTemp=n/s