Re: [CCAMP] Opsdir last call review of draft-ietf-ccamp-alarm-module-07

[stefan vallin <[e-mail]>]

Hi Joe!
Thanks for your review and comments!
See inline

br Stefan


> 
> I have been assigned to review this draft on behalf of the OPS DIR.  Overall, I
> found the draft ready with some nits.  I found relatively easy to read and
> well-thought-through.  Broadly speaking, I found the term "Alarm Shelving" to
> be confusing.  You do define this, but it is not something that many operators
> are familiar with.  I had originally thought alarm suppression was better, but
> after I read more, I see what you're trying to do with this.
Good :)
> 
> Additionally, some of the features like alarm-history and alarm-shelving have a
> potential operational impact with respect to local server resources, and
> perhaps that's worth calling out.
Good comment: suggested edits 
(could of course go somewhere else than in the feature desc)

     feature alarm-history {
       description
         "This feature indicates that server maintains a history of
          state changes for each alarm.  For example, if an alarm
          toggles between cleared and active 10 times, these state
          changes are present in a separate list in the alarm.
ADDED:
          The alarm-history feature has an impact on server memory 
          resources.         
          ";
     }


     feature alarm-shelving {
       description
         "This feature indicates that the system supports shelving
          (blocking) alarms.
ADDED:
          Alarm shelving has an impact on server processing resources
          in order to match alarms against shelf criterion";
     }


> 
> The leaf "has-clear" seems like it would read better as "has-cleared" from an
> English standpoint.  Thoughts?
Note well that this leaf is for the alarm *inventory*, not the alarm itself.
For the alarm itself the leaf is called "is-cleared".
The alarm inventory lists all candidate alarms and it is important for
operations to know if the server/instrumentation is capable of detecting
and generating alarm clear. So "has-clear" states that a specific alarm-type
will be cleared by the instrumentation when the alarm condition disappears.
I guess "has-clear" works in this context?
> 
> Finally, I can see where it might be desirable to suppress alarm notifications
> without shelving them per se.  That is, the alarm remains in the list, but
> notifications are not sent.  That doesn't seem possible, and I'm wondering if
> it's worth considering.
It is possible using the /alarms/control/notify-status-changes choice:
 leaf notify-all-state-changes {
             type empty;
             description
               "Send notifications for all status changes.";
           }
           leaf notify-raise-and-clear {
             type empty;
             description
               "Send notifications only for raise, clear, and re-raise.
                Notifications for severity level changes or alarm text
                changes are not sent.";
           }
           leaf notify-severity-level {
             type severity;
             description
               "Only send notifications for alarm state changes crossing
                the specified level.  Always send clear notifications.";
           }

You could consider turning all of by adding another leaf:
leaf notify-none {
   type empty;
   description
     "Don't send any notifications.";
 }
Not sure if that would make sense, recommend to leave that out for further study.
Note well that you can always stop to subscribe to the notification stream.


> 
> My per-section nits (typos) are found below.
Thanks!
Will correct


> 
> Section 3.2
> 
> s/an hierarchy/a hierarchy/
> 
> ===
> 
> Section 3.5.1
> 
> In the example, ((GigabitEthernet0/25, link-
>   alarm,""), false, T, major, "Interface GigabitEthernet0/25 down"), maybe
>   replace 'T' with a sample timestamp.  It took me a few seconds to grok that
>   as I was associating it with a boolean.
> 
> ===
> 
> Section 3.5.2
> 
> s/criteria/criterion/
> 
> ===
> 
> Section 3.6
> 
> s/the the disk full/the disk full/
> 
> ===
> 
> Section 3.7
> 
> s/this criteria/these criteria/
> 
> ===
> 
> Section 4.7
> 
> s/alarn/alarm/
> 
> ===
> 
> YANG Module section
> 
> s/identifiying/identifying/
> 
> s/exampla/example/
> 
> s/alarm is not longer active using other/alarm is no longer active using other/
>