.TH "helpers.conf" "5" "Slurm Configuration File" "July 2024" "Slurm Configuration File"

.SH "NAME"
helpers.conf \- Slurm configuration file for the helpers plugin.

.SH "DESCRIPTION"
\fBhelpers.conf\fR 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 \fBslurm.conf\fR.

.SH "PARAMETERS"
.LP
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.

.TP
\fBAllowUserBoot\fR=<\fIuser1\fR>[,<\fIuser2\fR>...]
Controls which users are allowed to change the features with this plugin.
Default is to allow ALL users.
.IP

.TP
\fBBootTime\fR=<\fItime\fR>
Controls how much time a node has to reboot before a timeout occurs and a
failure is assumed. Default value is 300 seconds.
.IP

.TP
\fBExecTime\fR=<\fItime\fR>
Controls how much time the Helper program can run before a timeout occurs
and a failure is assumed. Default value is 10 seconds.
.IP

.TP
\fBFeature\fR=<\fIstring\fR> \fBHelper\fR=<\fIfile\fR> <\fBFlags\fR=<\fIflags\fR>
Defines \fBFeature(s)\fR and a corresponding \fBHelper\fR program that reports
and modifies the status of the feature(s). Multiple \fBFeature\fR entries are
allowed, one for each feature and corresponding program/script. A comma
separated list of features can also be defined for one \fBHelper\fR.

Features can be defined per node by creating a unique file for each node. The
controller must have a \fBhelpers.conf\fR that lists all possible helper
features.

.RS
.TP
Currently supported flags are:
.IP

.TP
\fBrebootless\fR
Indicate that the feature doesn't require a node reboot. If
set, feature activation won't execute the \fIRebootProgram\fR, the node will
just register that the node rebooted to slurmctld without an actual reboot.
.RE
.IP

A single \fBhelpers.conf\fR can be created that defines features for specific
nodes by prepending \fINodeName=<nodelist>\fR to the front of the \fBFeature\fR
line. A \fBFeature\fR not prepended with \fINodeName\fR will apply to all
nodes.

.IP
.nf
# helpers.conf
NodeName=n1_[1-10] Feature=a1,a2 Helper=/path/helper.sh
NodeName=n2_[1-10] Feature=b1,b2 Helper=/path/helper.sh
Feature=c1,c2 Helper=/path/helper.sh
.fi

If a feature is defined in the \fBhelpers.conf\fR and is not defined on a
specific node in the \fBhelpers.conf\fR but is defined for that node in the
slurm.conf, that feature is treated as a changeable/rebootable feature by the
controller. For example, if feature \fIfa\fR is defined on node \fInode1\fR in
the \fBslurm.conf\fR but is only listed on \fInode2\fR in the
\fBhelpers.conf\fR, the feature will still trigger the node to be rebooted if
not active.

The \fBHelper\fR 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 \fBRebootProgram\fR.
The \fBHelper\fR program/script must be executable by the \fBSlurmdUser\fR.
The same program/script can be used to control multiple features. slurmd will
execute the \fBHelper\fR in one of two ways:
.IP
.RS
.LP
1. Execute with no arguments to query the status of node features. It must
return an exit code of 0 and either print a superset of the features expected
by Slurm, or it can print nothing. Otherwise, the node will be drained.
.LP
2. Execute with a single argument of the feature to be activated on node reboot.
In the case of multiple features the script is called multiple times.
.RE

.TP
\fBMutuallyExclusive\fR=<\fIfeature_list\fR>
Prevents certain features from being specified for the same job. There can be
multiple \fBMutuallyExclusive\fR 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).
.IP

.SH "EXAMPLE"

.TP
\fB/etc/slurm/slurm.conf\fR:
To enable the helpers plugin, the \fBslurm.conf\fR needs to have the following
entry:
.IP
.nf
NodeFeaturesPlugins=node_features/helpers
.fi

.TP
\fB/etc/slurm/helpers.conf\fR:
The following example \fBhelpers.conf\fR 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.
.IP
.nf
# helpers.conf
Feature=nps1,nps2,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
.fi

.TP
\fBExample Helper script\fR:
Helper scripts need to have the executable bit set and must exist on the
nodes, where they will be executed by slurmd.
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.
.IP
.nf
#!/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
.fi

.SH "COPYING"
Copyright (C) 2021 NVIDIA CORPORATION. All rights reserved.
.br
Copyright (C) 2021 SchedMD LLC.
.LP
This file is part of Slurm, a resource management program.
For details, see <https://slurm.schedmd.com/>.
.LP
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.
.LP
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.

.SH "SEE ALSO"
.LP
\fBslurm.conf\fR(5)