helpers.conf - Man Page

helpers.conf is an ASCII file which defines parameters used by Slurm's "helpers" node feature plugin. The file will always be located in the same directory as the slurm.conf.

Parameter names are case insensitive. Any text following a "#" in the configuration file is treated as a comment through the end of that line. The size of each line in the file is limited to 1024 characters. Changes to the configuration file take effect upon restart of Slurm daemons, daemon receipt of the SIGHUP signal, or execution of the command "scontrol reconfigure" unless otherwise noted.

AllowUserBoot=<user1>[,<user2>...]

Controls which users are allowed to change the features with this plugin. Default is to allow ALL users.

BootTime=<time>

Controls how much time a node has to reboot before a timeout occurs and a failure is assumed. Default value is 300 seconds.

ExecTime=<time>

Controls how much time the Helper program can run before a timeout occurs and a failure is assumed. Default value is 10 seconds.

Feature=<string> Helper=<file>

Defines a Feature and the corresponding Helper program that reports and modifies the status of the feature. Multiple Feature entries are allowed, one for each feature and corresponding program/script.

The Helper is an arbitrary program or script that reports and modifies the feature set on a given node. The helpers are site-specific and are not included with Slurm. Features modified by the helpers require a reboot of the node using the RebootProgram. The Helper program/script must be executable by the SlurmdUser. The same program/script can be used to control multiple features. slurmd will execute the Helper in one of two ways:

1. Execute with no arguments to query the status of node features.

2. Execute with a single argument of the feature to be activated on node reboot.

NOTE: Any feature under the control of a Helper cannot be requested with complex specification language. If any more complex specifications are specified by a job using constraints with "[]()!*", the job will be rejected.

MutuallyExclusive=<feature_list>

Prevents certain features from being specified for the same job. There can be multiple MutuallyExclusive entries, each with their own list of features that are mutually exclusive among themselves (i.e. features on one line are only mutually exclusive with other features on the same line, but not mutually exclusive with features on other lines).

/etc/slurm/slurm.conf:

To enable the helpers plugin, the slurm.conf needs to have the following entry:

NodeFeaturesPlugins=node_features/helpers

/etc/slurm/helpers.conf:

The following example helpers.conf demonstrates that multiple features can use the same Helper script and that there can be multiple lists of features that are mutually exclusive. For example, with the following configuration a job cannot request both "nps1" and "nps2", nor can it request both "mig=on" and "mig=off". However, it could request "nps1" and "mig=on" at the same time.

# helpers.conf
Feature=nps1 Helper=/usr/local/bin/nps
Feature=nps2 Helper=/usr/local/bin/nps
Feature=nps4 Helper=/usr/local/bin/nps
Feature=mig=on Helper=/usr/local/bin/mig
Feature=mig=off Helper=/usr/local/bin/mig
MutuallyExclusive=nps1,nps2,nps4
MutuallyExclusive=mig=on,mig=off
ExecTime=60
BootTime=60
AllowUserBoot=user1,user2

Example Helper script:

When the helper script is called with no arguments it should return the feature(s) that are currently active for the node, with multiple features being new-line delimited. When the helper script is called with a feature to be enabled for the node, it should configure the node in a way that the specified feature will be enabled when the node reboots. This example script just writes the active feature name to a file but production scripts will probably be more complex.

#!/bin/bash

if [ "$1" = "nps1" ]; then
    echo "$1" > /etc/slurm/feature
elif [ "$1" = "nps2" ]; then
    echo "$1" > /etc/slurm/feature
elif [ "$1" = "nps4" ]; then
    echo "$1" > /etc/slurm/feature
else
    cat /etc/slurm/feature
fi

Copyright (C) 2021 NVIDIA CORPORATION. All rights reserved.
Copyright (C) 2021 SchedMD LLC.

This file is part of Slurm, a resource management program. For details, see <https://slurm.schedmd.com/>.

Slurm is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

Slurm is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

slurm.conf(5)