Re: [SAGE] crontabs vs /etc/cron.[daily,hourly,*] vs. /etc/cron.d/

[Richard Chycoski <rskiadmin@xxxxxxxxxxxx>]

A true GANTT chart would also imply knowing task dependencies (unless 
you consider all tasks to be independent). Once you get to this stage, 
you should be considering more comprehensive 'batch processing' 
solutions that control these parameters (execution windows and 
dependencies).

The best that you can really do with cron is to show start times for 
jobs - with no mechanism to enforce dependencies or overruns, anything 
else is just guesswork.

(I currently work in a group that does batch job scheduling for a large 
environment, if you want to contact me privately.)

- Richard

John Miller wrote:
> On a more specific aspect of this (without regard to best practice), 
> does anyone know of a tool that converts crontabs into Gantt charts?
>
> I've always wanted to visualize how the crontab jobs (on a set of 
> machines) line up in time.  Each entry would need to be supplemented 
> with an estimate of the duration of the job (3 minutes vs 3 hours).
>
> JM
>
>
> Dustin J. Mitchell wrote:
> > On Jan 8, 2008 9:53 PM, Dustin Puryear <dustin@xxxxxxxxxxxxxx> wrote:
> > > 1. normal use of crontabs
> > > 2. creating a crontab-like entry in a file in /etc/cron.d/
> > > 3. creating symlinks to your scripts in /etc/cron.hourly/,
> > > /etc/cron.daily/, etc. (I'll just say /etc/cron.daily to be short.)
> > > 4. /etc/crontab for the root user being able to run cron jobs as any
> > > user, unlike /etc/cron.d/ and /etc/cron.daily/.
> >
> > I consistently prefer /etc/crontab.  When I have a box that's doing
> > something funny at 2:35am every morning, it's much easier to look in
> > just one place.  It's also easier to make sure that crontasks aren't
> > stepping on one anothers' toes that way.
> >
> > The directories are really only useful for distro authors, who need a
> > flexible way to add and remove tasks for particular applications.
> >
> > Dustin (the other Dustin)