Hi,

The main issue I have with this draft is that it's there's no way for the 
operator to get a list of all possible alarms on the device, without 
device-specific semantic knowledge.
They can get a list of all alarm *types*, but there's no information that says, 
for example, that a link-loss alarm can't be raised for a local CPU resource 
(or indeed, that the local CPU resource even exists).
This is exacerbated by the ability of operators can delete alarm entries; even 
if a device initially populates the alarm list with all possible alarms, the 
operator can still delete some of them, in which case the list no longer 
reflects all possible alarms.


We have an internally developed (but not yet published) YANG model for alarms 
which is very similar to this draft model, but with the following key 
differences:
* It does not track past status changes (they are stored in a separate event 
log); it is only concerned with current state.
* Alarms are associated with entities (from ietf-entity.yang) rather than 
arbitrary strings or instance-identifiers.
* It contains a list of all-alarms, regardless of whether they have ever been 
raised. This includes static information (description, severity) as well as 
current state information.
* It contains a separate list of raised-alarms, which mostly duplicates the 
information from all-alarms, but only contains an entry for an alarm if it is 
raised. This allows a subtree filter to retrieve only information about raised 
alarms, but it may be redundant.
* Instead of shelved alarms, we have a simple boolean "disabled" setting for 
each alarm; raised disabled alarms still appear as raised in the all-alarms 
list (with another indication they're disabled), but do not appear in the 
raised-alarms list.

With this model (and because ietf-entity.yang defines a hierarchy of entities) 
it is easy to display a hierarchical view of all entities and their associated 
alarms.

In our model, entries in the all-alarms list can only be added when resources 
are added to the system, and can only be deleted when resources are removed 
from the system.



Other comments:
* is-cleared feels like a double negation (false means "this alarm is not not 
raised"); I would like to see it changed to is-raised
* I would like to see a YANG feature for past status changes, or perhaps this 
part moved to a separate module augmenting ietf-alarms.
* has-clear doesn't need to be a union of only one type
* The meanings of "impacted resource" and "root cause resource" are unclear. 
* "This list is used to shelf alarms" should be "... to shelve alarms"
* "Shelv alarms for ..." should be "Shelve alarms for ..." (multiple 
occurrences)


Alex

________________________________________
From: netmod <[email protected]> on behalf of Martin Bjorklund 
<[email protected]>
Sent: Thursday, 6 October 2016 1:26 a.m.
To: [email protected]
Subject: [netmod] New Version Notification for  
draft-vallin-netmod-alarm-module-00.txt

Hi,

We have posted a new version of the alarm module.  The previous
document was called draft-vallin-alarm-yang-module-00, this new
version is called draft-vallin-netmod-alarm-module (hence it is also a
-00).

This updated version incorporates comments on the previous docuement,
and adds support for alarm shelving.

It would be good to know if people in this WG are interested in this
work.


/martin and stefan




A new version of I-D, draft-vallin-netmod-alarm-module-00.txt
has been successfully submitted by Martin Bjorklund and posted to the
IETF repository.

Name:           draft-vallin-netmod-alarm-module
Revision:       00
Title:          YANG Alarm Module
Document date:  2016-10-05
Group:          Individual Submission
Pages:          58
URL:            
https://www.ietf.org/internet-drafts/draft-vallin-netmod-alarm-module-00.txt
Status:         
https://datatracker.ietf.org/doc/draft-vallin-netmod-alarm-module/
Htmlized:       https://tools.ietf.org/html/draft-vallin-netmod-alarm-module-00


Abstract:
   This document defines a YANG module for alarm management.  It
   includes functions for alarm list management, alarm shelving and
   notifications to inform management systems.  There are also RPCs to
   manage the operator state of an alarm and administrative alarm
   procedures.  The module carefully maps to relevant alarm standards.

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