PMP Mail Archive: Re: PMP> Should Alerts be replicated???

PMP Mail Archive: Re: PMP> Should Alerts be replicated???

Re: PMP> Should Alerts be replicated???

JK Martin (jkm@underscore.com)
Sat, 01 Feb 1997 17:06:58 -0500

Chris Wellens wrote:

> On this question, Dave Perkins referred me to page 35, section 2.6.3
> "Event Triggering" in his book "Understandings MIBs":
>
> "There are two models for deciding whan an event has occurred....
> In the first, an event occurs when a monitored value first
> enters a range. This type of event is called "edge triggered."
> The monitored value must then enter a potentially different
> range before the event may occur again. (This is called
> rearming the trigger.)"
>
> "Alternatively, an event can be defined to occur when a monitored
> value is inside a range at the start of each periodic time
> interval. This type of event is called "level triggered." The
> event may "occur" only at each periodic interval. The
> DESCRIPTION clause must describe the modeling of the event. If
> the event is "edge triggered," the description must specify how
> the event is throttled or turned off so to keep from flooding
> network managers with event reports."

Bill Wagner then replied:

> 1. The comment that " If the event is "edge triggered," the
> description must specify how the event is throttled or turned off so
> to keep from flooding network managers with event reports." seems
> counter intuitive, at least for a printer. The specific example was
> running low on paper. An edge triggered treatment will reasonable
> result in many fewer events than a level treatment. One may argue that
> throttling (or setting the reporting period) is required for level but
> not for edge.

You know, in reading Chris' quoted text from Dave Perkins' book, I can't
help
but wonder if either Perkins' text is misstated, or Chris' mistyped the
text
from the book.

I mean, the key sentence (to which Bill refers) is:

"If the event is "edge triggered," the description must specify how
the event is throttled or turned off so to keep from flooding network
managers with event reports."

Now, this sentence is in the paragraph explicitly describing "level
triggered" events; the discussion on "edge triggered" events was
described in the preceding paragraph. Why wouldn't this key sentence
be part of the "edge triggered" paragraph? Moreover, the warning
about "flooding network managers with even reports" would seem to be
likely with "level triggered" events (which, by definition, can be
generated multiple times for a given condition) than for "edge
triggered"
events (which, by definition, should only be generated once, when the
condition first arises).

I think we have a typo here, don't you?

...jay

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