[rrd-users] Re: Adding "0" instead of nothing when there's no data

Rejo Zenger subs-rrd-users at sisterray.xs4all.nl
Wed Sep 18 21:11:53 MEST 2002

++ 18/09/02 18:47 +0200 - Alex van den Bogaerdt:
>>                         "DS:articles:ABSOLUTE:50400:U:U",
>>                         "DS:bytes:ABSOLUTE:50400:U:U",
>ABSOLUTE: real number of {articles|bytes} divided by delta time.
>Example:  you enter "6000:1200000", the resulting rates will be
>6000/60 and 1200000/60.  100 Articles/sec, 200000 bytes/sec.

Ok, I got that right. :)

Just keep in mind that I'm talking about the Dutch nl.* hierarchy only,
it's about 130 groups big and has a total volume of 12 to 14 Mb per day
only. The number of articles per group per minute are low.

>50400: Updates received 50400 seconds apart result in unknowns.
>This is "a bit" high.  What do you try to achieve?

If there's no data coming in, there is no feed. That should be reflected
with just a simple "0¨ articles and "0" bytes. I want to use the unknown
part to show abnormal long time no feed only. I do not recall how I got
to that number, but 10080 would be usefull (7 days no feed: there must
be a problem somewhere).

>>                         "RRA:AVERAGE:0.5:1:600",
>600 CPDs of 1 PDP per CDP  --> 600 minutes.

I find these abreviations confusing. But even without the abreviations I
find it hard to understand the meaning of each of the fields. The first
one is obvious. The second also, but ony if it is AVERAGE. What exactly
the MAX, MIN and LOW function do is unclear to me (or at least, not
*that* clear, and the manpage doesn't really help there).

If I understand this correct, the fourth field says how many data is
used for every point in the graph. The fifth field tells you how many of
those points are used for the entire graph. Right?

So, if you use 5 datapoints for a total of 600 graph points, this would
be perfectly for a graph with a timespan with a timespan of 3000 minutes
(if step was set to 60 seconds). Right?

Then function of this third field, I'm complete gone.

>> I'm not sure if those RRA's fit my goals.
>This depends on your goals.  If you want to show graphs that display
>1,5,30,120 or 1440 PDPs in each pixel, you did the right thing.
>This equals: 1 pixel==1 minute, 1 pixel==5 minutes, 1 pixel==30 minutes
>and so on.

Well. I want to create graphs of 600 pixels wide. I want to have an
hourly, daily, weekly, monthly and a yearly graph. Thus, for the daily I
would need 1440 graphpoints of each 1 datapoints (resulting in a total
of 1440 minutes of data, which equals 24 hours). Is this way of thinking

>> - How to get these two average lines, I don't know how to compute them
>>   and how to place them.
>You already start with averages, RRDtool continues to work with
>averages, your consolidation factor is averages.  You have nothing
>but averages.

I understand and this would give me the perfect average for an AREA.
But, on top of that I would like to have a two more lines. So, in the
yearly graph there should be an average of postings per day, one line
with an average computed as the average of postings when looking at a
timewindow of 30 days and an average computed as the average of postings
when looking at a timewindow of 90 days.

>> - On the preliminary graphs I have created already, the numbers to the
>>   left say "<number> m". It's not clear to me where this "m" is coming
>>   from. I have read the "Grpahics with some maths" section in the
>>   tutorial, but still don't get it in the relation to my numbers.
>That's mili.  One article in a minute results in 1/60 articles per
>second which will be displayed as 16.667 mili-articles per second.

Ok. So, so if I want to have it displayed as articles per second I have
to add the line "CDEF:art_avg_2=art_avg,60,*" to the graph? If, at a
certain point, there were 2 postings in one minute, this would show as a
line at "2.0". It looks to be good now, I just want to be certain... :)

>Try using "CDEF:perminute=persecond,60,*" and display that.

Hehehe. Note to self: first read entire message, than comment. :)

Thank you! I have probably some more days to go before the results are
the way I want them, bit this is looking promissing...

# Rejo Zenger
# rejo at sisterray.xs4all.nl, pgp: see headers, http://www.xs4all.nl/~sister

Unsubscribe mailto:rrd-users-request at list.ee.ethz.ch?subject=unsubscribe
Help        mailto:rrd-users-request at list.ee.ethz.ch?subject=help
Archive     http://www.ee.ethz.ch/~slist/rrd-users
WebAdmin    http://www.ee.ethz.ch/~slist/lsg2.cgi

More information about the rrd-users mailing list