Fetch 5 minute data from a "large RRA w/out cons.?"

[gm20175]

Hello,

Without issue, we have implemented very large RRAs without consolidation per gandalf's excellent instructions: http://docs.cacti.net/node/54

We are using the yearly RRA parameters as specified, and Cacti provides "high resolution" graphical data wonderfully. Thank you!

One question, how does one FETCH 5 minute data from the RRA for a duration of time greater than a few days?

$ rrdtool fetch [rrd file] AVERAGE -r 1 -s 1month

If, for example. the above syntax is used, 2 hour data is returned.

Any ideas on how to fetch other resolutions from such RRAs?

Appreciate any help! Thanks gandalf for your guidance!

Thank You,
gm20175

[gandalf]

One question, how does one FETCH 5 minute data from the RRA for a duration of time greater than a few days?

$ rrdtool fetch [rrd file] AVERAGE -r 1 -s 1month

If, for example. the above syntax is used, 2 hour data is returned.

What makes you think so?
Perhaps I should add a chapter on my so-called "graphical aggregation"? Remember: When fetching 5 min data for as much as a month, you will get that many data points:
12 (for an hour) * 24 (for a day) * 30 (for a month) = 8640 data points
To graph them independantly, you would need a graph of that pixel width! It would be very, very wide. To keep it within the standard boundaries, rrdttool applies the standard consolidation function (not during fetch operation but during graph operation, which, unfortunately, gives the same results). Using cli, it is possible to force rrdtool to not use AVERAGE as a graphing consolidation function but MAX, MIN or LAST. IMHO, not a single one of those makes more sense than AVERAGE.
Reinhard

[gm20175]

Thanks for your reply Reinhard,

...when the above syntax is used, 2 hour data is returned.

What makes you think so?

Because we have used the above command line syntax on a RRA created with the parameters specified in your document, and 2 hour space'ed data points are returned. Cacti and graphing is fine! We are not trying to graph the data points; we wish to perform calculations on 1 month of data at 5 minute resolution (not 2 hours).

Using cli, it is possible to force rrdtool to not use AVERAGE as a graphing consolidation function...

Really, what is the syntax to mine 5 minute resolution from this RRA (for a month)?

Thank You,
Gregory

[gandalf]

Ah, now I understand better. I was more focused on rrdtool graph and did not read your first post exactly. Sorry for that. Please try

Code: Select all

       --resolution│-r resolution (default is the highest resolution)
               the interval you want the values to have (seconds per value). rrdfetch will try to match your
               request, but it will return data even if no absolute match is possible. NB. See note below.

as an option to "rrdtool fetch". Did not try on my own but may help. More info available from "man rrdfetch".
Reinhard