Ubuntu Manpage: scrontab - manage Slurm crontab files

Provided by: slurm-client_23.02.3-2ubuntu1_amd64

NAME

       scrontab - manage Slurm crontab files

SYNOPSIS

       scrontab [-u user] file
       scrontab [-u user] [ -e | -l | -r ]

DESCRIPTION

scrontab is used to set, edit, and remove a user's Slurm-managed crontab. This file can
define a number of recurring batch jobs to run on a scheduled interval.

Lines must be either comments starting with '#', whitespace, valid crontab entries or
custom variable settings.

Lines starting with #SCRON allow options to be defined for the single following crontab
entry. Options are always reset in between each crontab entry. Options include most of
those available to the sbatch command; details are available in the sbatch(1) man page.

Note that jobs are not guaranteed to execute at the preferred time. Jobs will run no more
frequently than requested, but are managed by setting the BeginTime field to the next
valid iteration, and are then subject to queuing delays. The exact behavior will depend on
the local site configuration. Because of this method of implementation, the next job in
the series won't be submitted until after the previous job has completed. For example, if
you have a monitoring job that is scheduled to run every minute on a busy system, if the
job scheduled to start at 08:20:00 isn't able to start until 08:20:30 and it runs for 35
seconds then the job at 08:21:00 will be skipped and the next job will be scheduled for
08:22:00.

scrontab uses the same syntax for date and time specifiers as cron. Each line has five
fields that have the following meanings:
field allowed values
----- --------------
minute 0-59
hour 0-23
day of month 1-31
month 1-12 (or name)
day of week 0-7 (0 and 7 are Sunday, or use name)

A field can contain an asterisk (*) which means that it's valid for each of the allowed
values for the given time period. Ranges are allowed where a range is two numbers with a
hyphen between them. The second number must be greater than the first. Lists are allowed,
with commas separating the numbers or ranges being separated. Step values can be specified
by entering a slash (/), followed by the step value, causing the job to run at the
specified interval appropriate for that field.

Custom variables can be defined as within a regular shell script. The `$' character
introduces variable expansion. Simple parameter expansion is the only currently accepted
expansion variant (i.e. ${parameter} or ${parameter:-word} are not supported). The
variable expansion will only occur within scrontab job commands. It is not possible to
expand variables in other type of lines (other variable definitions, comments or crontab
entries). The expansion will happen before submitting the job, but the variable
definitions will remain in the scrontab script. Unlike crontab, the user environment
variables are ignored.

OPTIONS

       The first form of this command is used to install a new crontab from some  named  file  or
       standard input if the pseudo-filename ``-'' is given.

       -e     Edit  the  crontab. If a crontab does not exist already, a default example (without
              any defined entries) will be provided in the editor.

       -l     List the crontab. (Prints directly to stdout.)

       -r     Remove the crontab. Any currently running crontab-defined jobs will continue to run
              but will no longer recur. All other crontab-defined jobs will be cancelled.

       -u <user>
              Edit  or  view  a  different user's crontab. Listing is permitted for Operators and
              Admins. Editing/removal is only permitted for root and the SlurmUser account.

SCRONTAB OPTIONS

       scrontab allows you to use shortcuts  to  specify  some  common  time  intervals  for  the
       specified script to run.  These include the following:

       @yearly | @annually
              Job will become eligible at 00:00 Jan 01 each year.

       @monthly
              Job will become eligible at 00:00 on the first day of each month.

       @weekly
              Job will become eligible at 00:00 Sunday of each week.

       @daily | @midnight
              Job will become eligible at 00:00 each day.

       @hourly
              Job will become eligible at the first minute of each hour.

ENVIRONMENT VARIABLES

       VISUAL              Used as the interactive editor if set.

       EDITOR              Used as the interactive editor if set and VISUAL is not defined.

       SLURM_CONF          The location of the Slurm configuration file.

       SLURM_DEBUG_FLAGS   Specify  debug  flags  for  scrontab  to  use.  See  DebugFlags in the
                           slurm.conf(5) man page for a  full  list  of  flags.  The  environment
                           variable takes precedence over the setting in the slurm.conf.

NOTES

       scrontab  is  only  available if the ScronParameters=enable option has been enabled in the
       slurm.conf.

       scrontab will create a temporary file in the directory set by TMPDIR environment variable.
       If the variable is not set /tmp is used.

       Jobs created with scrontab are assigned a single job id. When cancelled all future runs of
       the job will also be cancelled. The job definition will be  commented  out  in  the  users
       scrontab file.

       Using "scontrol requeue <job_id>" will skip the next run of the cron job and reschedule it
       for the next available time based on the cron expression.

EXAMPLES

       To create a job that would run at the beginning of each hour, using the 'high'  partition,
       'sub1' account and have a walltime of 1 minute, you would add the following to scrontab:

              DIR=/home/user1
              #SCRON -p high
              #SCRON -A sub1
              #SCRON -t 1:00
              @hourly $DIR/date.printer.job

       To have a job run every Wednesday, every other hour during the work day, each of the first
       five minutes of the hour and again at the thirty minute mark, you would add the  following
       to scrontab.

              1-5,30 8-17/2 * * wed $DIR/example.job

LIMITATIONS

       The Slurm controller's timezone is what will be used to evaluate each crontab's repetition
       intervals. User-specific timezones are not supported.

COPYING

       Copyright (C) 2020-2022 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.