On Sun, Apr 13, 2003 at 02:12:03PM -0400, Greg A. Woods wrote:
> [ On Sunday, April 13, 2003 at 16:09:05 (+0200), Manuel Bouyer wrote: ]
> > Subject: Re: CVS commit: src/sbin/ifconfig
> >
> > On Sat, Apr 12, 2003 at 06:30:20PM -0400, John Hawkinson wrote:
> > > 
> > > Why is it necessary to support clearing counters at all?
> > > It seems to add a lot of pain for not a lot of benefit.
> > 
> > I (and others) find it a usefull feature. Maybe I work too much with
> > cisco switches :)
> 
> What, exactly, is the technical usefulness of being able to zero
> counters?

No technical reasons. It's just convenient.

> 
> So far the only really good reason I've seen mentioned is that it's
> easier for most humans to deal with smaller numbers when looking at
> counters, especially when trying to understand the delta relationships
> between several such counters.
> 
> If that's the only real reason for wanting to be able to zero counters
> then that's not really any reason at all -- rather it's just an feature
> requirement for the tool used to retrieve and view those counter values,
> and the solution already exists, in netstat with '-w wait' (and could be
> augmented with '-c count' ala the other *stat programs).

it's not as convenient as zeroing the counters. You can come 2 hours, or a
day after zeroing them and see how they moved.

> 
> Note too that Cisco IOS usually deals with counters in exactly the way
> Bill suggested too, IIUC.  They never zero the real counter, but just
> set some presentation offset for the CLI user.

Yes, and this is what I like.

> 
> Now I think the command-line tools should always show the real counter
> values, not the delta from the last "reset" point, and that a special
> option be required to show the latter.  However this brings us back to
> the question of why '-w wait' isn't a sufficient and complete
> replacement for the combination of marking the "reset" point and showing
> the delta from that "reset" point, since it provides almost exactly the
> same functionality, especially for any CLI that provides decent job
> control features.

-w wait just shows you the difference with the last display. You can't track
how the counters increase with that.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 24 ans d'experience feront toujours la difference
--