Subject: Pairing instances

From: "David T. Perkins" <[email-masked]>
Date: Wed, 17 Apr 2002 23:28:40 -0700

HI,

In the alarm MIB (the 06 draft), how does one specify in the
alarm model table (or elsewhere) how to determine the value
for object alarmActiveResourceId? Without being able to
specify this programically, it doesn't look like having
configurable alarms is doable.

One needs to have values of alarmActiveResourceId so that
clears can be paired with existing active alarms. For example,
if one "configured" linkDown notifications to raise alarms
and linkUp notifications to clear them, then if a linkDown
occurred on interface 1, and then a link down occurred on
interface 9, and then a linkUp occurred on interface 9,
you would need values of alarmActiveResourceId to know
which of the two active alarms to clear. But, there is no
way to configure this.

Regards,
/david t. perkins

---

From: "Romascanu, Dan (Dan)" <[email-masked]>
Date: Thu, 18 Apr 2002 16:07:41 +0300

David,

See 4.1.4 for the definition of alarmActiveResourceId, and example 6.1 for the configuration of alarms based on linkUp/linkDown. The correspondence is built upon matching the indices with the values of index point to by linkUp to the indices pointed to by alarmActiveResourceId. This looks to me pretty  obvious. Do you think that there is need for more explanation, or maybe do you think that an alarm may be triggered on interface 1 and cleared on interface 9? (I do not think this is a practical case)

Regards,

Dan

> -----Original Message-----
> From: David T. Perkins [mailto:[email-masked]]
> Sent: Thursday, April 18, 2002 9:29 AM
> To: [email-masked]
> Subject: Pairing instances
> 
> 
> HI,
>

---

From: "David T. Perkins" <[email-masked]>
Date: Thu, 18 Apr 2002 13:36:53 -0700

HI,

Yes, its obvious to human readers (and, of course, I gave an example
that should be well understood). But, if arbitrary notifications
that are well defined for human readers are configured, how is the
code that determines the value of alarmActiveResourceId suppose to
figure this out? It seems like a little bit of magic for code.

Also, in re-reading X.733/ISO-10164-3, it appears that there can be
the cases:
 1) multiple active alarms on the same instance
 2) multiple correlated active alarms
in which one clear notification causes all to clear.

How is this specified in the model table?

Regards,
/david t. perkins

---

From: Randy Presuhn <[email-masked]>
Date: Mon, 22 Apr 2002 17:55:49 -0700 (PDT)

Hi -

> Message-Id: <[email-masked]>
> Date: Mon, 22 Apr 2002 17:39:12 -0700
> To: Randy Presuhn <[email-masked]>, [email-masked]
> From: "David T. Perkins" <[email-masked]>
> Subject: RE: Pairing instances
> In-Reply-To: <[email-masked]>
...
> The example below is interesting, but I'm talking about something
> really basic. 

Much simpler than your example.  ;-)

The question about how the

...
> code would determine the value of "alarmActiveResourceId" from
> the notifications is not described. 
...

Agreed.  This is a problem.

Summing up, we have similar concerns about the alarmModelTable.
A partial list, paraphrasing (or possibly reading too much
into) your posts:

   1) how does it the implementation figure out where to get
      the value for alarmActiveResourceId?  (The information
      has to be in the notification somewhere, but how does
      the alarmModelTable tell the implementation where to
      look?)

   2) what is the appropriate amount of power for describing
      the "finite state machine" for an alarm?

   3) can a single notification "crank" more than one alarm's
      state machine?  (This is tied to (1))

 ------------------------------------------------------
 Randy Presuhn          BMC Software, Inc.  1-3141
 [email-masked]  2141 North First Street
 Tel: +1 408 546-1006   San José, California 95131  USA
 ------------------------------------------------------
 My opinions and BMC's are independent variables.
 ------------------------------------------------------

---

From: "Sharon Chisholm" <[email-masked]>
Date: Wed, 24 Apr 2002 16:30:44 -0400

hi

My recollection is that hierarchical clearing was defined
out of scope. It could always be supported as an add-on
at a later date with a mechanism something like a 
hierarchicalClearTable that associated a clearNotification 
with a list of alarmModels.

Sharon

-----Original Message-----
From: David T. Perkins [mailto:[email-masked]]
Sent: Thursday, April 18, 2002 4:37 PM
To: Romascanu, Dan (Dan); [email-masked]
Subject: RE: Pairing instances

HI,

At 04:07 PM 4/18/2002 +0300, Romascanu, Dan (Dan) wrote:
>David,
>
>See 4.1.4 for the definition of alarmActiveResourceId, and example 6.1 for
the configuration of alarms based on linkUp/linkDown. The correspondence is
built upon matching the indices with the values of index point to by linkUp
to the indices pointed to by alarmActiveResourceId. This looks to me pretty
obvious. Do you think that there is need for more explanation, or maybe do
you think that an alarm may be triggered on interface 1 and cleared on
interface 9? (I do not think this is a practical case)
Regards,
/david t. perkins

---

From: Randy Presuhn <[email-masked]>
Date: Wed, 24 Apr 2002 14:41:45 -0700 (PDT)

Hi -

> Message-ID: <[email-masked]>
> From: "Sharon Chisholm" <[email-masked]>
> Date: Wed, 24 Apr 2002 16:14:00 -0400
...
> Currently it is assumed that the implementer has some
> knowledge of the notification being used in the model.
...

As WG chair I'd like a consensus check on this point, since
it clearly has significant impact on both the document and
implementations.  The Question:

   Shall we require implementations of this MIB to have
   built-in knowledge of know how to extract resource IDs
   from all the notification types they might encounter?
   (rather than representing how the resource ID is to be
   extracted in the MIB)