[rrd-users] can't sanity-check rrdtool with sample data ...please help

[Marc Powell]

> -----Original Message-----
> From: rrd-users-bounces at lists.oetiker.ch [mailto:rrd-users-
> bounces at lists.oetiker.ch] On Behalf Of Gore Jarold
> Sent: Wednesday, June 27, 2007 3:14 PM
> To: Simon Hobson; rrd-users at lists.oetiker.ch
> Subject: Re: [rrd-users] can't sanity-check rrdtool with sample data
> ...please help


> 
> So this is the other problem - and I'll just make the
> question easy:
> 
> If my update command is:
> 
> rrdtool update hits.rrd 1141286400:1 1141372800:10
> 1141459200:10 1141545600:12 1141632000:12
> 1141718400:12
> 
> and I want my output with fetch to give me:
> 
> 1,10,10,12,12,12
> 
> Then what is wrong with my 'rrdtool create' statement:
> 
> rrdtool create hits.rrd --start 1141200000 --step
> 86400 DS:hits:GAUGE:172800:0:U RRA:MAX:0.5:1:3650
> 
> because right now, instead of the 1,10,10,12,12,12
> that I put in, I am getting:
> 
> 1141257600: 1.0000000000e+00
> 1141344000: 7.0000000000e+00
> 1141430400: 1.0000000000e+01
> 1141516800: 1.1333333333e+01
> 1141603200: 1.2000000000e+01
> 1141689600: 1.2000000000e+01
> 
> when I fetch it back out ... (1,7,10,11.3,12,12)

Your insert timestamps are not even multiples of your step from the
epoch. As you can see, rrdtool is adjusting the data so that they are.
It does this by interpolating what the data would be at that timestamp
based on the rate of change. If you want to get the exact same data out,
you need to insert with a 00:00:00 GMT timestamp. 

--
Marc