[rrd-users] RRDtool spread values by time on rrd, how to turn off this behavior?
linux at thehobsons.co.uk
Mon Apr 16 20:22:22 CEST 2012
Daniel Hilst wrote:
what must be the most frequently asked question on this list
>2) The feed it with:
>rrdtool update test.rrd 1334578211:10
>rrdtool update test.rrd 1334578221:0
Terse answer: This is normal behaviour, it is **EXACTLY** how RRD is
intended to work, and no you can't turn it off.
RRD is designed to do one thing well, normalise and store data at
specified resolutions, in an economic way. It is not a general
purpose database - if you want to store arbitrary data for arbitrary
times and get the original data out then you should use a regular
**ALL** data is normalised and consolidated according to the
parameters used when creating the database. With some care* it is
possible to make the normalisation a null operation, and using a
consolidation process of one data point consolidated into one
consolidated data point will make the consolidation a null operation
as well - but both processes are still performed.
Alex has an excellent set of tutorials at
In particular, see "Rates, normalizing and consolidating"
* To make normalisation a null operation, you must supply data values
every step time, and they must be timestamped **exactly** on the step
time boundary. These boundaries are always an integer multiple of
step time since unix epoch (midnight, Jan 1, 1970 UTC) and this
cannot be changed.
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