SLURM Using Features and Constraints

Using Features/Constraints with SLURM

Features/Constraints allow users to make very specific requests to the scheduler such as what interconnect your application prefers, how much available memory you require, whether you mind running on low priority machines, etc. To get the most out of the queuing environment, it is very useful to have a reasonable understanding of how the features work and which features you should request for your type of application.

Important Features

The following table lists custom defined features/constraints which are necessary for getting your job to run on the right hardware.

Feature Name	Value	Description	Default
--time	Wall clock time limit	Request and set a certain amount of run-time for your job. Jobs are killed when they reach this limit	1 hour
--mem	Memory per node	mem (defined in megabytes) will set the amount of memory allocated per node. (For serial jobs)	512MB (0.5GB)
--mem-per-cpu	Memory per core	mem (defined in megabytes) will set the amount of memory allocated per cpu core. (For multi-core jobs)	512MB (0.5GB)

Requesting Features/Constraints

To request a feature/constraint, you must add the following line to your submit script:

#SBATCH --constraint=<feature_name>

 
where <feature_name> is one of the features defined above (or one of the standard features described in the SLURM User’s Guide and shown below).

To request multiple features/constraints, you must add the following line to your script using one of the following operators below:

Operator Function	Operator Symbol	Example
AND	& (ampersand)	#SBATCH --constraint=“cpu_xeon&sse4”
OR	| (pipe)	#SBATCH --constraint=“xeon_E52630|xeon_E52650|xeon_E52670”

An example:

#!/bin/bash
#SBATCH --name=my_job_needs_qdr_infiniband
#SBATCH --time=02:00:00
#SBATCH --ntasks=8
#SBATCH --mem-per-cpu=4096
#SBATCH --constraint=ib_qdr
#SBATCH --output=output.$SLURM_JOB_ID

mpirun /opt/apps/my_app/my_binary

• Job requests 2 hours of runtime (time=02:00:00)
• Job requests 32GB of memory (4GB per CPU)
• Job requests only nodes with Quad Data Rate Infiniband

Feature Table

This is a table of user-addressable SLURM features. You can request machines with a variety of characteristics such as machines with a certain amount of memory or a particular architecture type.

Feature	Description
cpu_amd	Select only nodes with AMD cpus
cpu_xeon	Select only nodes with Intel Xeon cpus only
gpu_T10	Select only nodes with T10 GPU (used with --gres. Refer to the GPU Guide for more info)
gpu_M2070	Select only nodes with M2070 GPU (used with --gres. Refer to the GPU Guide for more info)
gpu_K20	Select only nodes with K20 GPU (used with --gres. Refer to the GPU Guide for more info)
ib_sdr	Select only nodes with Infiniband Single Data Rate
ib_ddr	Select only nodes with Infiniband Double Data Rate
ib_qdr	Select only nodes with Infiniband Quad Data Rate
ib_ofa	Select only nodes with Mellanox Infiniband cards
ib_psm	Select only nodes with QLOGIC Infiniband cards
opteron_2220	Select only nodes with AMD Opteron 2220 CPU chips
opteron_2384	Select only nodes with AMD Opteron 2384 CPU chips
opteron_2427	Select only nodes with AMD Opteron 2427 CPU chips
sse4	Select only nodes with sse4 (and above) CPU instruction set
sse41	Select only nodes with sse41 (and above) CPU instruction set
sse4a	Select only nodes with sse4a (and above) CPU instruction set
sse42	Select only nodes with sse4a (and above) CPU instruction set
xeon_X5355	Select only nodes with Intel Xeon X5355 CPU chips
xeon_X5460	Select only nodes with Intel Xeon X5460 CPU chips
xeon_E5649	Select only nodes with Intel Xeon E5649 CPU chips
xeon_E7330	Select only nodes with Intel Xeon E7330 CPU chips
xeon_E52630	Select only nodes with Intel Xeon E5-2630 CPU chips
xeon_E52650	Select only nodes with Intel Xeon E5-2650 CPU chips
xeon_E52670	Select only nodes with Intel Xeon E5-2670 CPU chips