[Zope-dev] Xron fragility

[Loren Stafford]

From: "Chris McDonough" <chrism@digicool.com>


> > > As a side note, I do not like the fact that Xron requires you to
use
> special
> > > DTML methods.  I suppose this is a requirement in this
architecture due
> to
> > > the fact they need to be autocataloged, but I don't really like
that
> feature
> > > either :-).
> >
> > I think Xron could work with anything that has "trigger" and
"disarm"
> > methods, that gets put into the Schedule catalog.
>
> I guess I'm not real real hot on the dependency on a catalog at all.
I'm
> having a hard time imagining a situation where you have so many events
that
> you need to index them -- especially using a ZCatalog.  It just seems
like
> too many moving parts and overkill for the job.  :-)
>

ZCatalog is overkill, but it was convenient for quick development of
Xron. The essential characteristics of the Schedule are:

1. Quickly determine what the next scheduled event is.

2. Automatically update when scheduling parameters of sheduled methods
change.

3. Quickly determine how long Dispatcher should sleep (if sleeping model
is used).

4. Manage concurrency of Schedule changes initiated by different
scheduled methods

-- Loren