[rrd-users] Tutorial Question

[David Eisner]

I'm an rrdtool neophyte. I've been experimenting with simulated data
and am also working through the rrdtutorial. [1]

According to the tutorial:

--snip_begin--
We can now retrieve the data from our database using "rrdtool fetch":

 rrdtool fetch test.rrd AVERAGE --start 920804400 --end 920809200

It should return the following output:

                          speed

 920804700: nan
 920805000: 4.0000000000e-02
 920805300: 2.0000000000e-02
 920805600: 0.0000000000e+00
 920805900: 0.0000000000e+00
 920806200: 3.3333333333e-02
 920806500: 3.3333333333e-02
 920806800: 3.3333333333e-02
 920807100: 2.0000000000e-02
 920807400: 2.0000000000e-02
 920807700: 2.0000000000e-02
 920808000: 1.3333333333e-02
 920808300: 1.6666666667e-02
 920808600: 6.6666666667e-03
 920808900: 3.3333333333e-03
 920809200: nan

If it doesn't, something may be wrong.  ...
--snip_end--


When I do this (using rrdtool 1.4.4), however, I get an extra NaN
value at the end:

--snip_begin--
$ rrdtool fetch test.rrd AVERAGE --start 920804400 --end 920809200
                          speed

 920804700: nan
 920805000: 4.0000000000e-02
 920805300: 2.0000000000e-02
 920805600: 0.0000000000e+00
 920805900: 0.0000000000e+00
 920806200: 3.3333333333e-02
 920806500: 3.3333333333e-02
 920806800: 3.3333333333e-02
 920807100: 2.0000000000e-02
 920807400: 2.0000000000e-02
 920807700: 2.0000000000e-02
 920808000: 1.3333333333e-02
 920808300: 1.6666666667e-02
 920808600: 6.6666666667e-03
 920808900: 3.3333333333e-03
 920809200: nan
 920809500: nan
--snip_end--

Is there a bug in the tutorial, in rrdtool, or in my brain?

Thanks.

-David

[1] http://www.mrtg.org/rrdtool/tut/rrdtutorial.en.html


-- 
David Eisner     http://cradle.brokenglass.com