[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

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