[hobbit] Questions on "howtograph.txt"

[Henrik Stoerner]

Hi Larry,

On Mon, Feb 06, 2006 at 09:55:35AM -0500, Sherman, Larry, GCM wrote:
> 
> I have been attempting to implement NCV graphing in hobbit, on version
> 4.1.2 and have run into a few problems/questions:
> 
> First, the question:  In the "slab" example, you custom test sends the
> string "inode_cache" but in your NCV_slab entry in hobbitserver.cfg, you
> have "inodecache:GAUGE".  How does this work???  

Hobbit silently strips everything except letters and numbers from the 
dataset name. So "inode_cache" is stripped of the underscore, and
becomes "inodecache". Section 4) of the "howtograph.txt" document
explains this:

   4) Arrange for the data to be collected into an RRD file
   ========================================================
   The data is obviously a name-colon-value formatted report, so we'll use the
   NCV module in Hobbit to handle it. Hobbit will find two datasets here:
   The first will be called "inodecache", and the second "dentrycache"
   (note that Hobbit strips off any part of the name that is not a letter
   or a number; Hobbit also limits the length of the dataset name to 19
   letters max. since RRD will not handle longer names).


> Second, the problem:  We have a custom test which checks printer toner
> levels by going to the web page of the printer with lynx.  Our test,
> called "toner" sends data in the format:
> 
>  lj102.toner
> 
> 	black     : 67
> 	cyan      : 56
>       magenta   : 78
>       yellow    : 43
> 
> The data does go into the rrd, but does not appear in the "<last_ds>"
> field, as in your slab example, but rather in the <value> field.  Our
> graph shows up, but there is no data in it.

Could you show us the first part of the "rrdtool dump" output for the
RRD file ?

My guess is that you've accidentally defined the RRD datasets with the
"DERIVE" datatype (the default) instead of "GAUGE" which is what you'll
need for this kind of data.

> PS:  I have been a BB user since 1999, and moved our servers to hobbit
> last Fall.  We absolutely love it.  Thanks Henrik!

You're welcome :-)


Regards,
Henrik