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Re: Creating a randomized cron entry

This one time, at band camp, Don Armstrong said:
> On Thu, 15 Dec 2005, Florian Weimer wrote:
> > I'd like to create a cron entry which is run once a day, at some
> > random time.  This is necessary because the cron entry will result
> > in a request over the network, and I want to avoid that all hosts in
> > a time zone pound the server at the same time.
> Why not just something like:
> 0 0 * * * at now + $(( $RANDOM \% 1440 )) minutes [...]

Because that's a bashism, and some dash user will get upset with you.

Probably the most portable way to handle it is to run the job from
cron.daily, but call a wrapper script that sleeps for a random amount of
time less than one day before runnign the actual job.  For extra
goodness, use a lock file so that if the last random sleep was 23 hours
and 59 minutes, and the next one is 1 minute, you don't two jobs at

Take care,
|   ,''`.                                            Stephen Gran |
|  : :' :                                        sgran@debian.org |
|  `. `'                        Debian user, admin, and developer |
|    `-                                     http://www.debian.org |

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