[Xymon] Green status during a total blackout

[Henrik Størner]

On 27-07-2011 13:05, L.M.J wrote:
> On Wed, 27 Jul 2011 11:54:04 +0100, Neil Simmonds wrote:
>> If your Xymon server was down how could it recognise that it had not
>> received any data?
>
> Yes, but when it restarted, can't it see any data/graphs has been update
> for hours ? What about updating rrd graphs with a 6h hole ?
> It turns purple when no data has been reported since 30min ? Xymon turns
> itself to purple without having notification, doesn't it ?

You have a valid point, but Xymon is - by design - essentially 
event-driven when it comes to updates: It won't update anything unless 
it receives some sort of notification that something has changed. And 
when it is down, it doesn't receive anything.

Yes, Xymon could look at the RRD files and see that they haven't been 
updated. There might be other reasons for that, though - e.g. the 
xymond_rrd module might have crashed, but the rest of Xymon has been 
running fine.

And what happens if all your tests go purple immediately when Xymon is 
brought back on-line ? You'll potentially fire off all the alerts you 
have configured. At a time when things are really running OK...

So it's a design choice to behave the way it does. If your entire 
datacenter has been down because of a power outage, people will know. 
They don't need the Xymon history to learn about that.


Regards,
Henrik