T.R | Title | User | Personal Name | Date | Lines |
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3768.1 | alarms scheduling is very simple (?) | MOLAR::ROBERTS | Keith Roberts - Network Management Applications | Fri Sep 18 1992 11:24 | 38 |
|
Brad,
If you tell alarms to run every 30 minutes, it polls for data when
you enabled the rule .. and requests the Information Manager to keep
track of the time and let alarms know when the scheduling time is up,
then alarms polls again.
The first poll will require the MM which alarms calls to get loaded
in memory .. this might take a second or two. Then, accessing the
entity might take many seconds or minutes. The time stamp alarms
returns is when alarms actually evaluates the rule. There is also
a timestamp from the polled entity .. which is usually a tiny bit
different from the timestamp alarms returns.
In your example (100 entities polled every 5 minutes) ... If the poll
takes longer than scheduled time, the Information Manager returns a
'time already passed' error to alarms. Alarms will ignore this error
(up to 10 times I think) and just keep calling the IM until the call
goes through .. in your example the timing would be:
schedule time = at every 00:05:00
time 00:00:00 Alarms processes the 100 rules - takes 12 minutes
time 00:10:00 Missed this one
time 00:15:00 The first call took 12 mintues, so the IM waits
for the *next* scheduled time. this takes 12 minutes
time 00:20:00 Missed this one
time 00:25:00 Missed this one too.
time 00:30:00 The second poll took 12 minutes so we missed the 20
and 25 minute schedule .. alarms polls again.
Yuck .. so, your 5 minute scheduling turned into 15 minutes scheduling.
I thought this was going to make things clearer - but rereading it, I
don't know. Did this help?
/keith
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3768.2 | understood, but what if | CTHQ::WOODCOCK | | Fri Sep 18 1992 11:51 | 36 |
| Hi keith,
> Yuck .. so, your 5 minute scheduling turned into 15 minutes scheduling.
>
> I thought this was going to make things clearer - but rereading it, I
> don't know. Did this help?
Yes sir it does, but for a sanity check I added a couple of words to the
example. Does it still look accurate?
schedule time = at every 00:05:00
time 00:00:00 Alarms processes the 100 rules - takes 12 minutes
> time 00:05:00 Missed this one
time 00:10:00 Missed this one
> time 00:15:00 The first call took 12 mintues, so the IM waits
for the *next* scheduled time. the next sceduled time
is the 15 minute marker so alarms polls again here.
this takes 12 minutes
time 00:20:00 Missed this one
time 00:25:00 Missed this one too.
time 00:30:00 The second poll took 12 minutes so we missed the 20
and 25 minute schedule .. alarms polls again.
What happens when an interval is missed? Does the user see the error in any
form (alarm is in batch)? Comments: I certainly wouldn't want to get an
exception for every wildcarded entity polled within the rule (which I don't
think is the case), but I would like to see a single error somewhere, somehow,
someshape. Does an internal event get generated? If the alarm is DOMAIN xxx
RULE yyy will the following rule fire if an interval gets missed?:
expr=(occurs(domain xxx rule * OSI RULE EXCEPTION))
many thanks,
brad...
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3768.3 | No notification is made if a time interval is skipped | MOLAR::ROBERTS | Keith Roberts - Network Management Applications | Fri Sep 18 1992 13:08 | 32 |
| >What happens when an interval is missed? Does the user see the error in any
>form (alarm is in batch)? Comments: I certainly wouldn't want to get an
>exception for every wildcarded entity polled within the rule (which I don't
>think is the case), but I would like to see a single error somewhere, somehow,
>someshape. Does an internal event get generated? If the alarm is DOMAIN xxx
>RULE yyy will the following rule fire if an interval gets missed?:
>
>expr=(occurs(domain xxx rule * OSI RULE EXCEPTION))
Nope 8{
The only time you'll get an indication that a time interval has been
missed is if there are 10 in a row (I think the number is 10).
So, if you said 'at every 00:00:01' ... and it took 11 seconds to
process the rule, you'll get the "time already passed" exception back
from the evaluation process via, I believe, the "Error Condition"
status attribute.
Now you probably want to know:
(Q) "How can I find out when a time interval gets skipped? (other than
when 10 of them are skipped)"
(A) You can't that I can think of.
Might be nice if Alarms maintained a counter attribute: "Time Intervals
Missed". If you saw this counter going up regularly you'd know there
was a problem. Could even imagine getting PA involved to calculate
statistics.
/keith
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3768.4 | Intervals missed=good idea | CTHQ::WOODCOCK | | Fri Sep 18 1992 14:35 | 15 |
| > (A) You can't that I can think of.
Bummer eh...
> Might be nice if Alarms maintained a counter attribute: "Time Intervals
> Missed". If you saw this counter going up regularly you'd know there
> was a problem. Could even imagine getting PA involved to calculate
> statistics.
Interfacing to PA probably isn't worth it but "Time Intervals Missed" would
be a useful counter for figuring out what's amuck when alarms aren't coming
when you think they should be.
thanks,
brad...
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