[rrd-users] Newby questions

[Tobias Oetiker]

Today Pablo Chacin wrote:

> Greetings all
>
> I'm new to rrdtools. I'm actually still evaluating it as as tool for
> storing monitoring metrics.
> After reading the documentation and several discussions in this list and
> also in other forums
> I'm still confused about a couple of things.
> 1. How are subsecond timestamt reported? In several places it is
> mentioned the existence of these timestamps, but can't find any example
> of how to specify it in the update command, except when using "N" as
> timestamp.

  rrdtool update 1351545246.3897:394.33

> 2. Supposing subsecond timestamps are supported by rrdtools, are they
> also supported by rrdcached?

  I think the version on github does support it ... the released
  version not.
>
> 3. Finally, is there any patch to add SUM function for totalizing a
> metric over a period. This is a very important requirement as we need to
> count the total number of certain events for minute, hour and day. I'm
> aware of the approach of using the average and multiplying by the
> reporting period, but this will lead to a approximated value.

  everything in rrdtool is a 'rate' so even if there was such a
  function the math would still be the same ... can yo elaborate in
  what way you expect the result of the calculation to be an
  aproximation?

> Even when
> I understand the concerns about it not working properly in all
> situations, I think is a very common requirement. Simply can't believe
> nobody has done this ever, unless I'm completely wrong about the need of
> such function.

cheers
tobi

> many thanks in advance
>
>
>

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch tobi at oetiker.ch ++41 62 775 9902 / sb: -9900