CRONTABS(4) Crontabs users' Manual CRONTABS(4)NAMEcrontabs - configuration and scripts for running periodical jobs
SYNOPSIS
run-parts <directory>
DESCRIPTION
Crontabs is a historical name for the run-parts script and the system
crontab. The run-parts script runs all executables in the specified
directory.
The crontab file contains configuration which calls the run-parts
script on files in the /etc/cron.{daily,weekly,monthly}/ directories.
Randomization of jobs can be configured in the /etc/sysconfig/run-parts
file. To enable randomization of jobs, set the RANDOMIZE parameter to 1
and set the RANDOM parameter to an integer which determines a random
seed. Additionally, you may configure the RANDOMTIME parameter (again,
by specifying an integer) to provide an additional level of randomiza‐
tion. Jobs are not randomized when the RANDOM and RANDOMTIME parameters
are set to 0. Values in these two parameters must be set to 1 or larger
to provide a good enough randomization.
Randomization of cron jobs can be useful for shared networks, where
multiple cron jobs executed at once can cause spikes in traffic, espe‐
cially during daily jobs. With randomized jobs, the workload is evenly
distributed throughout the day.
EXAMPLE OF CONFIGURATION FILE
RANDOMIZE=1
RANDOM=4
RANDOMTIME=8
SEE ALSOcrontab(5)Marcela Mašláňová 2012-08-29 CRONTABS(4)