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Re: discontinuity timers for Counters
On Tue, Jul 27, 2004 at 11:01:43AM +0200, Wijnen, Bert (Bert) wrote:
>
> Discontinuities in the value of this counter can occur at
> re-initialization of the management system, and at other
> times as indicated by the value of
> ifCounterDiscontinuityTime."
> And if so, this text would probably be better.
Yes.
> So the ptr to RFC2863 would be to sect 3.1.5 I assume, specifically
> to the text on page 12.
> Or did you mean something else?
I meant the text on page 12 which talks about discontinuities.
> > Looking at the MIB, the question that I have is the interaction of
> > discontinuities with these ZeroBasedCounter32 objects. Does a
> > discontinuity couse these counters to be reset to zero?
>
> I believe that we (MIB doctors) agree that they cannot state that a
> ZeroBasedCounter32 MUST be re-initialized to zero at some point
> in time (they are only required to be zero at creation time).
> So I had them remove that sort of text from an earlier revision.
> So current text is silent about it, meaning that an implementation
> could do anything, right? There is a discontinuity, so we need to
> start with new values and then check at least 2 queries.
If I have to compute deltas after the first discontinuity anyway, why
use ZeroBasedCounter32? If my application can't be sure to track all
discontinuities, then it has to compute deltas to produce meaningful
results. I tend to believe that Counter32 is actually the more
appropriate type in this scenario.
> Nope, I do not think the index is constantly changing. But that is a
> typical use case, not the only use case is it? At least I never
> considered that to be a pre-requisite for the use of ZeroBasedCounter32.
A ZeroBasedCounter32 in a conceptual row which can experience
discontinuities as part of its normal operational behaviour
just seems a bit odd to me. I fail to see what the advantage of
a ZeroBasedCounter32 in such a situation is.
/js
--
Juergen Schoenwaelder International University Bremen
<http://www.eecs.iu-bremen.de/> P.O. Box 750 561, 28725 Bremen, Germany