[rrd-users] Re: 95th Percentile - Values stored inside RRD file

Hwee Khoon, Neo hweekhoon.neo at pacific.net.sg
Thu Mar 24 09:59:08 MET 2005


Thanks Serge, I've changed it to Counter type and I now see that the output
of rrdfetch is in transfer rates.

Basically the router is returning me the amount of bytes that has been
transferred for every 300 seconds of SNMP poll. Because this value is
cumulative, there will come a time where it's being resetted to 0 due to
overflow.

I'm curious if rrd is capable of detecting that the value has wrapped around
and compute the value correctly. Do I need to specify somewhere (like during
the creation of the rrd file) that the max value is (2^64-1)

Thanks.
HK

The Counter64 class represents a 64bit unsigned integer type. It is used for
monotonically increasing values that wrap around at 2^64-1
(18446744073709551615).


-----Original Message-----
From: rrd-users-bounce at list.ee.ethz.ch
[mailto:rrd-users-bounce at list.ee.ethz.ch]On Behalf Of Serge Maandag
Sent: Friday, March 18, 2005 12:13 AM
To: Hwee Khoon, Neo; Rrd-Users
Subject: [rrd-users] Re: 95th Percentile - Values stored inside RRD file


> > 3) I noticed the raw data inside RRD file contains the
> > cumulative figure (e.g. the octet count is always
> > increasing). Is it possible for me to configure RRD such that
> > it computes the transfer speed and then store them into the
> > file? Instead of dumping the exact figure to the file.
>
> I did a rrdfetch and here's a sample of what I got:
>
> 1111047600:  4.1100088879e+08  4.0569527413e+08
> 1111047900:  4.1204431180e+08  4.0673533156e+08
> 1111048200:  4.1280187560e+08  4.0748254008e+08
>
> my rrd file is created with the option:
> 	"-s 300",
> 	"DS:ioct:GAUGE:600:0:U",	#input traffic datasource
> 	"DS:ooct:GAUGE:600:0:U",	#output traffic datasource
> 	"RRA:AVERAGE:0.5:1:28800"
>
> because the value (InOctets) is always inreasing, I choose
> GAUGE thinking
> that it will help me compute the average and store them in
> the rrd file.

If the input keeps increasing, then is probably is a COUNTER value.
As in an snmp byte counter. If you query it every 300 seconds, then
you get the amount of bytes that have passed during that 300 seconds.

I see no advantage in storing that as a gsuge value in your rrd
database. The only interesting value is the amount of bps that have
passed and that would be automatically computed is you use a counter
ds type.

What everage do you want to compute?

serge.

-------------
Op de inhoud van dit e-mailbericht en de daaraan gehechte bijlagen is de
inhoud van de volgende disclaimer van toepassing:
http://www.zeelandnet.nl/disclaimer.php

--
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


--
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