[rrd-users] value and name both

Simon Hobson linux at thehobsons.co.uk
Mon Nov 21 19:56:10 CET 2011

Shabnam Shahreza wrote:

>Imagine this is one of the printed outputs which I got by using 
>"AVERAGE 1" comparing file1/2/3:
>	print[10] = "7.843519 \n"
>This search fails to show me which one of file1/2/3 has this value:
>rrdtool fetch -s -1y file1 AVERAGE 1 | grep 843519
>rrdtool fetch -s -1y file2 AVERAGE 1 | grep 843519
>rrdtool fetch -s -1y file3 AVERAGE 1 | grep 843519
>Even I dumped the output but still unable to locate the value....
>Is this due to some normalization or something?

Almost certainly.

rrdtool fetch simply returns the data stored in the database - it 
does **NOT** do any data manipulation. rrdgraph on the other hand 
will resample the data to fit your graph unless you take care to make 
this a null operation.

Even if you use rrdtool graph, I would not try finding data like that 
- it only takes a very small change in conditions for that exact 
value to not appear.

However, in the example I gave, you did not have to look for a value 
(at least not in a separate run) - what you printed was an index to 
the data set that gave rise to the value you were after. Ie, you 
wouldn't get something like 7.843519 and have to find where it came 
from, you'd get (for example) 1, 2, or 3 - signifying source 1, 2, or 
3 respectively.
And BTW - please don't try and take threads off-list unless asked to. 
It's impolite both to the person your asking for one-to-one help from 
and to the rest of the people on the list who may well be able to 
assist. Also, it means the conversation doesn't go into the list 
archives for the benefit of others looking for answers later.

Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.

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