[hobbit] Create RRD ´s

[Henrik Stoerner]

On Mon, May 23, 2005 at 02:12:04PM -0300, GF lists wrote:
> 
> 	It's not about the resolution of RRD file but about the data
> inside it.
> 	Now lard makes the graphics with collected data for the last 5
> minutes, but I need the same graphic with 1 minute ago.
> 
> Where is the file where I can set it!?

You cannot.

The RRD code in Hobbit assumes that your graphs have 576 data items each 
(see hobbitd/do_larrd.c - the "RRA" definitions), and it uses the
default RRDtool "step" value of 300 seconds. There are no "knobs"
defined to tune any of these settings, except that you are free to
rewrite the code any way you please - courtesy of the GPL license.

I have no idea how much work it would be to implement a customizable
resolution for you RRD's, but my feeling is that it would not be a
simple matter. You'll need to look at the hobbitd/do_larrd.c and 
hobbitd/larrd/*.c files for handling the RRD file creation and
updating, and the hobbitd/hobbitgraph.c and web/zoom.js files for the 
graph generation.

Reading up on the rrdcreate and rrdgraph man-pages (from RRDtool) is probably 
a good idea.

But before you do, consider this: Most tests in Hobbit (and BB) run only once 
every 5 minutes - a 1 minute graph doesn't make much sense for something 
that only changes in 5 minute intervals.


Regards,
Henrik