On Wed, Jul 07, 2004 at 06:14:13PM +0200, ciaran deignan wrote: > The RRD documentation "reccomends" setting MIN and MAX values for > all data-sources when creating the RRD files. But all the examples > show this with a GUAGE DS-type, where MAX is obviously the biggest value > the counter can ever hold.
Rates, not datasources. > How is MAX interpreted for a COUNTER DS-type? Does it represent the > maximum increment over the previous data-point? What if the previous > data-point is two "steps" back in time? Is the MAX a maximum per-step > increment? Or is it configured as a rate directly and multiplied by > the step interval and the number of steps? Everything in an RRA is a rate. DSes are used to compute the rate. A DS of GAUGE (note: not GUAGE) means the number already _is_ a rate. For a COUNTER: If you skip a step or two, and if heartbeat allows to update anyway, the rate is still computed as (counter_now-counter_then)/(time_now-time_then). For all DSes: The resulting rate, after normalization, is checked against min and max. > For example, I'm just starting to experiment with RRD, and I'm logging > sysUpTime from SNMP as a sanity check. The rate-of-change of the counter > is one-second-per-second ;) Should I declare the DS as > > rrdtool create --step 60 DS:sysUpTime:COUNTER:360:0:60 > or > rrdtool create --step 60 DS:sysUpTime:COUNTER:360:0:1 > ??? Is uptime in seconds? If so, I guess 1 is the appropriate value, however I would add a few percent to cope with rounding errors. HTH Alex -- I ask you to respect any "Reply-To" and "Mail-Follow-Up" headers. If you reply to me off-list, you'd better tell me you're doing so. If you don't, and if I reply to the list, that's your problem, not mine. -- Unsubscribe mailto:[EMAIL PROTECTED] Help mailto:[EMAIL PROTECTED] Archive http://www.ee.ethz.ch/~slist/rrd-users WebAdmin http://www.ee.ethz.ch/~slist/lsg2.cgi
