Re: Time & CmdSchedule

[Aaron Turner <aturner@linuxkb.org>]

On Fri, 3 Dec 1999, Jason Pincin wrote:

> > First, stupid me didn't make sure NTP started last time Vodka got
> > rebooted.  Hence it was a little over an hour behind (daylight savings).
> 
> Good job Aaron!  :)

yeah, yeah, rub it in. :)
 
> > Also (and this is mostly for Jason, but anyone can chime in), I noticed
> > that you created the scheduling system very cron like.  Not being a cron
> > expert, I wondered what happens for something like:
> > 01 01 2 * sun 
> > Now, Dec 2, 1999 is today (ie, not Sunday) and yet this cronjob would of
> > executed today (imperical evidence).  I thought that this was kinda
> > strange: Run on the second of each month and every Sunday at 1:01am.
> > So how do you want CmdSchedule.pl to act?  Like cron or different?  Will
> 
> Hm.  So CRON does sumthin like an "or" eh?  I wasn't aware of that, but I was thinking that the CmdSchedule
> system operate more like "and"-style, meaning all the fields had to match.  Unless you or anyone else thinks
> there is good reason for our purposes to make this "or"-style.

I think doing an "and" makes more sense.  This wierd "or" thing is only
going to confuse.

> > your PHP tools allow someone to do that?  Is your PHP tool to manage the
> > table going to do bounds checking (Feb 31st for example)?  Jason, do you
> 
> Yes, it'll do bounds checking.  You don't have to worry about that.

Cool.

> > really have time for this, or should it be delegated to someone else?
> 
> Well, you might be overestimating what I'm doing :), and might be
> thinking of CmdSchedule differently than I. I'm not creating ANY web
> forms for this.  I'm leaving that up to other people.  The only thing
> I'm creating right now, are the DB's (done with perhaps minor mods
> coming), and a PHP function to add a command to it, one to modify an
> existing entry, and one to remove.  3 functions is all.

Okey doke.
 
> I assume someone will want to create some type of admin form using
> these functions to allow admins to manually examine and control the
> scheduling system... but that's not the primary purpose of the table
> in my mind.  The primary purpose was to allow lower level things to

Yeah, I was thinking that we'll need that.

> easily interact with the system in ways external to PHP.  So if
> someone was creating a page that they would like to have email
> confirmations sent off for... (which may be common), someone will make
> a confirmation email script for general use - design it to the specs
> given, and then anyone can send confirmation emails by doin sumthin
> like:

[snip]

> So yes, answer to your question is "yes", I have time to do what I
> intend :)  I hope this clears up my intentions for the system
> somewhat?

Yep.
 
> > Also, do I need to support ranges and step values?
> > 0,15,30,45 */2 2-5 * *
> 
> Yes, if you can please :)

Can-do.  I'll just have to modify your select statement some and do the
ranges/step checking in Perl unless you know a way to do this in SQL.  No
biggie to do it in perl though.

> > I also wondered about how to determine the difference between run once and
> > run many jobs?
> > * * * * * 
> > may mean run every minute of every day or it may mean "just run next time"
> > I think we should have a repeating field which is either an integer or *.
> > If a * then it runs until disabled/removed.  If an integer, it runs and
> > reduces the value by one.  When it reaches zero, it becomes disabled.
> 
> If you look at the CmdSchedule table, you'll see a field called
> CmdType.  Thats what this field was for... "Immediate" or "Scheduled".  
> Any one set to "Immediate" was a run only once type thing.  It was
> executed, and if succesful, removed from the table.  "Scheduled" ones
> stayed forever.  As you can see, Aaron's suggestion here has MUCH more
> flexibility, and I like it very much.  My former "Immediate" types
> would just be 1's, and my former "Scheduled" would just be *'s with
> Aaron's suggestion - and we would have everything in between... so we
> could tell something to run 3 times, then be removed from the schedule
> system.  I like that!
> 
> Aaron - I'll change the CmdType field to RepeatCount and it will work
> just as you described... cool? (I'm changing it now actually)

Uh, I notice that RepeatCount is a SmallInt(5).  Does that support the *
character?  If not, no biggie, we can use -1 to describe infinate, but we
need to define the standard.
 
--
Aaron Turner, Core Developer       http://vodka.linuxkb.org/~aturner/
Linux Knowledge Base Organization  http://linuxkb.org/
Because world domination requires quality open documentation.
aka: aturner@vicinity.com, aturner@pobox.com, ion_beam_head@ashtech.net