[rrd-users] rrd at the ragged edge (updates every second)
Simon Hobson
linux at thehobsons.co.uk
Tue Apr 19 19:41:40 CEST 2011
Rick Jones wrote:
> > AIUI, if you use "N" (now) for the update time, then internally RRD
>> uses sub-second timing and you can update more frequently. It does
>> mean that your update "happens" when you submit the call rather than
>> when you take the timestamp, but for your setup I doubt that's a huge
> > issue.
> > you can input time with millisecond precision, then this will not
>> happen
>>
>> 1303164367.002
> > 1303164367.393
>is there any additional subtle differences between the two I should know
>about before picking one or the other?
"N" means the time you make the call, nnn.nnn means a specific time
which may be different to when you make the call. It's particularly
important if the script that collects data and prepares the update
takes a long time between collection and update (perhaps some complex
conversions). If the script takes very little time to run, the two
options are near enough the same in effect.
When I wrote the above I wasn't aware you could use decimals in an update time.
--
Simon Hobson
Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
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