[rrd-users] rrd fetch changes between 1.0 and 1.2

[Tobias Oetiker]

Hi Gergely,

not realy ...


note that the entry at 1170422700: contans data valid between:
1170422400 and 1170422700.

You could argue that in this case 1.2 is giving too much data back
by also returning the data for the interval following 1170423300
this is right, BUT all rrdtool fetch garantees you is that it will
return as much data as is required to 'cover' the time frame
specified with start and end ...

note that there have bben some adjustments to the algorithm during
the 1.2 life cycle, so make sure you use the latest version.

cheers
tobi


 Madarasz wrote:

> Hello,
>
> I just found that rrdtool fetch works differently in 1.0 and 1.2:
>
>
> 1.0:
>
> # rrdtool fetch some.rrd AVERAGE --start 1170422400 --end 1170423300
> timestamp    42
>
> 1170422400:  1.0666666667e-03
> 1170422700:  2.6133333333e-02
> 1170423000:  1.0471937984e-01
> 1170423300:  2.6379611625e-01
>
> 1.2:
>
> # rrdtool fetch some.rrd AVERAGE --start 1170422400 --end 1170423300
>                              42
>
> 1170422700: 2.6133333333e-02
> 1170423000: 1.0471937984e-01
> 1170423300: 2.6379611625e-01
> 1170423600: nan
>
>
> So 1.0 actually gives data corresponding to the interval asked in the
> command line, while 1.2 gives an off-by-one result. Can someone please
> tell me what is the reason for this? An url is fine if already discussed,
> I just couldn't find any good search terms for it.
>
>

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten
http://it.oetiker.ch tobi at oetiker.ch ++41 62 213 9902