niceload - man pages section 1: User Commands

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niceload (1)

Name

niceload - slow down a program when the load average is above a certain limit

Synopsis

niceload [-v] [-h] [-n nice] [-I io] [-L load] [-M mem] [-N]
[--sensor program] [-t time] [-s time|-f factor] ( command |
-p PID )

Description

parallel NICELOAD(1)

NAME
niceload - slow down a program when the load average is
above a certain limit

SYNOPSIS
niceload [-v] [-h] [-n nice] [-I io] [-L load] [-M mem] [-N]
[--sensor program] [-t time] [-s time|-f factor] ( command |
-p PID )

DESCRIPTION
GNU niceload will slow down a program when the load average
(or other system activity) is above a certain limit. When
the limit is reached the program will be suspended for some
time. Then resumed again for some time. Then the load
average is checked again and we start over.

Instead of load average niceload can also look at disk I/O,
amount of free memory, or swapping activity.

If the load is 3.00 then the default settings will run a
program like this:

run 1 second, suspend (3.00-1.00) seconds, run 1 second,
suspend (3.00-1.00) seconds, run 1 second, ...

OPTIONS
-f FACTOR
--factor FACTOR
Suspend time factor. Dynamically set -s as amount
over limit * factor. Default is 1.

-H
--hard Hard limit. --hard will suspend the process until
the system is under the limits. The default is
--soft.

--io iolimit
-I iolimit
Limit for I/O. The amount of disk I/O will be
computed as a value 0 - 10, where 0 is no I/O and
10 is at least one disk is 100% satuated.

--io will set both --start-io and run-io.

--load loadlimit
-L loadlimit
Limit for load average.

--load will set both --start-load and run-load.

--mem memlimit
-M memlimit

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Limit for free memory. This is the amount of bytes
available as free + cache. This limit is treated
opposite other limits: If the system is above the
limit the program will run, if it is below the
limit the program will stop

memlimit can be postfixed with K, M, G, T, or P
which would multiply the size with 1024, 1048576,
1073741824, or 1099511627776 respectively.

--mem will set both --start-mem and run-mem.

--noswap
-N No swapping. If the system is swapping both in and
out it is a good indication that the system is
memory stressed.

--noswap is over limit if the system is swapping
both in and out.

--noswap will set both --start-noswap and run-
noswap.

-n niceness
--nice niceness
Sets niceness. See nice(1).

-p PID
--pid PID
Process ID of process to suspend.

--quote
-q Quote the command line. Useful if the command
contains chars like *, $, >, and " that should not
be interpreted by the shell.

--run-io iolimit
--ri iolimit
--run-load loadlimit
--rl loadlimit
--run-mem memlimit
--rm memlimit
Run limit. The running program will be slowed down
if the system is above the limit. See: --io,
--load, --mem, --noswap.

--sensor sensor program (alpha testing)
Read sensor. Use sensor program to read a sensor.

This will keep the CPU temperature below 80 deg C
on GNU/Linux:

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niceload -l 80000 -f 0.001 --sensor 'sort -n /sys/devices/platform/coretemp*/temp*_input' gzip *

This will stop if the disk space < 100000.

niceload -H -l -100000 --sensor "df . | awk '{ print \$4 }'" echo

--start-io iolimit
--si iolimit
--start-load loadlimit
--sl loadlimit
--start-mem memlimit
--sm memlimit
Start limit. The program will not start until the
system is below the limit. See: --io, --load,
--mem, --noswap.

--soft
-S Soft limit. niceload will suspend a process for a
while and then let it run for a second thus only
slowing down a process while the system is over one
of the given limits. This is the default.

--suspend SEC
-s SEC Suspend time. Suspend the command this many seconds
when the max load average is reached.

--recheck SEC
-t SEC Recheck load time. Sleep SEC seconds before
checking load again. Default is 1 second.

--verbose
-v Verbose. Print some extra output on what is
happening. Use -v until you know what your are
doing.

EXAMPLE: See niceload in action
In terminal 1 run: top

In terminal 2 run:

niceload -q perl -e '$|=1;do{$l==$r or print ".";
$l=$r}until(($r=time-$^T)>50)'

This will print a '.' every second for 50 seconds and eat a
lot of CPU. When the load rises to 1.0 the process is
suspended.

EXAMPLE: Run updatedb
Running updatedb can often starve the system for disk I/O
and thus result in a high load.

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Run updatedb but suspend updatedb if the load is above 2.00:

niceload -L 2 updatedb

EXAMPLE: Run rsync
rsync can just like updatedb starve the system for disk I/O
and thus result in a high load.

Run rsync but keep load below 3.4. If load reaches 7 sleep
for (7-3.4)*12 seconds:

niceload -L 3.4 -f 12 rsync -Ha /home/ /backup/home/

EXAMPLE: Ensure enough disk cache
Assume the program foo uses 2 GB files intensively. foo will
run fast if the files are in disk cache and be slow as a
crawl if they are not in the cache.

To ensure 2 GB are reserved for disk cache run:

niceload --hard --run-mem 2g foo

This will not guarantee that the 2 GB memory will be used
for the files for foo, but it will stop foo if the memory
for disk cache is too low.

ENVIRONMENT VARIABLES
None. In future versions $NICELOAD will be able to contain
default settings.

EXIT STATUS
Exit status should be the same as the command being run
(untested).

REPORTING BUGS
Report bugs to <[email protected]>.

AUTHOR
Copyright (C) 2004-11-19 Ole Tange, http://ole.tange.dk

LICENSE
Copyright (C) 2010,2011,2012 Free Software Foundation, Inc.

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

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version 3 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 MERCHANTABILITY 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, see
<http://www.gnu.org/licenses/>.

Documentation license I
Permission is granted to copy, distribute and/or modify this
documentation under the terms of the GNU Free Documentation
License, Version 1.3 or any later version published by the
Free Software Foundation; with no Invariant Sections, with
no Front-Cover Texts, and with no Back-Cover Texts. A copy
of the license is included in the file fdl.txt.

Documentation license II
You are free:

to Share to copy, distribute and transmit the work

to Remix to adapt the work

Under the following conditions:

Attribution
You must attribute the work in the manner specified
by the author or licensor (but not in any way that
suggests that they endorse you or your use of the
work).

Share Alike
If you alter, transform, or build upon this work,
you may distribute the resulting work only under
the same, similar or a compatible license.

With the understanding that:

Waiver Any of the above conditions can be waived if you
get permission from the copyright holder.

Public Domain
Where the work or any of its elements is in the
public domain under applicable law, that status is
in no way affected by the license.

Other Rights

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In no way are any of the following rights affected
by the license:

o Your fair dealing or fair use rights, or other
applicable copyright exceptions and limitations;

o The author's moral rights;

o Rights other persons may have either in the work
itself or in how the work is used, such as
publicity or privacy rights.

Notice For any reuse or distribution, you must make clear
to others the license terms of this work.

A copy of the full license is included in the file as
cc-by-sa.txt.

DEPENDENCIES
GNU niceload uses Perl, and the Perl modules POSIX, and
Getopt::Long.

ATTRIBUTES
See attributes(5) for descriptions of the following
attributes:

NOTES
This software was built from source available at
https://java.net/projects/solaris-userland. The original
community source was downloaded from
http://ftp.gnu.org/gnu/parallel/parallel-20121122.tar.bz2

Further information about this software can be found on the
open source community website at
http://www.gnu.org/software/parallel/.

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