JSD(1) General Commands Manual JSD(1)
NAME
jsd - job scheduler daemon
SYNOPSIS
jsd [ -V | --version ] [ -v | --verbose | -d level | --debug=level ] [
-h | --help ] [ -p | --paths ] [ -n | --simulate ] [ -r res:qty[,...]
| --resources=res:qty[,...] ] [ --suspend ]
DESCRIPTION
Jsd is a very simple job scheduler daemon. It "manages" an arbitrary
set of system resources (e.g. memory, CPUs, disk space) and executes
jobs that have been submitted (see jss(1)) when their demand for re-
sources can be met.
CONFIGURATION
None
OPTIONS
-d level, --debug=level Determines how verbose this program will be.
The message types displayed for the different
values of level are as follows: 0 displays no
messages; 1 displays only errors, 2 displays
errors and warnings; 3 displays errors, warn-
ings and informational messages; higher values
display errors, warnings, informational mes-
sages and various messages intended for debug-
ging. The default is 2.
-h, --help Displays a brief usage message.
-p, --paths Lists the compiled-in paths of various files
and directories that this program uses. -n,
--simulate Some external commands that this
program runs may be displayed rather than ac-
tually executed. BEWARE: different programs
implement different levels of simulation; so
this option may work perfectly; on the other
hand it may do nothing at all!
-v, --verbose Equivalent to -d 3.
-V, --version Prints the program's version number and exits.
-r res:qty[,...], --resources=res:qty[,...]
Specifies the names of the resources and the
quantities of each of them initially avail-
able. res must adhere to the usual definition
of a word; qty must be an integer. It is an
error for no resources to be specified.
--suspend Start jsd with the scheduler suspended. See
jsc(1)'s suspend and resume commands for more
information.
EXIT STATUS
On success jsd returns zero. On failure it returns non-zero and dis-
plays a diagnostic message.
FILES
None.
ENVIRONMENT VARIABLES
JS_NAME or LOGNAME If JS_NAME is set then it is used to set the
name of the instance of jsd(1). If that is
not set then LOGNAME is used instead. If that
is also not set then an error occurs.
JS_res_AFFINITY Set to the specific resources that have been
allocated, e.g.:
JS_CPU_AFFINITY=0-3,16-19
JS_res_LIMIT Set to the count of resources that have been
allocated, e.g.:
JS_CPU_LIMIT=8
EXAMPLES
This command manages some standard resources:
MEM=$(head -1 /proc/meminfo | awk '{ print $2 }')
CPU=$(grep -c '^processor' /proc/cpuinfo)
jsd --resources=mem:$MEM,cpu:$CPU
This command manages some considerably less standard resources:
jsd --resources=alexis:1,suzie:1,peter:1,jane:1
CAVEATS
Jsd has no understanding of resource types; it simply maintains a list
of the quantity of each resource that currently executing jobs are con-
suming and if a job can be executed without exceeding the specified
maximum available quantities of all resources, then it runs that job.
See also the CAVEATS section of jss(1).
Affinity is enforced through jsd's use of js-shepherd. js-shepherd is
currently not documented.
STANDARDS
This manual page documents version 2 of jsd.
SEE ALSO
js-config(1), jsc(1), jsq(1), jss(1), taskset(1)
AUTHOR
Alexis Huxley <alexishuxley@gmail.com>
COPYRIGHT & DISTRIBUTION POLICY
Copyright (C) 2015-2024 Alexis Huxley
This program 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.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MER-
CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
675 Mass Ave, Cambridge, MA 02139, USA.
26 Jul 2024 JSD(1)
