Trend Predictions Using RRDtool and Cacti

[TheWitness]

All,

I wanted to upload this in case people have questions relative to using RRDtool for performing trend analysis. It's a great write-up of where you can take a modern Cacti, and I would like to thank the author.

[TheWitness]

Here is also a good article on HoltWinters.

https://www.usenix.org/legacy/events/li ... index.html

and for Prediction:

https://hints.jeb.be/2009/12/04/trend-p ... h-rrdtool/

I'll post additional resources here separate from several others discussions that have taken place on the forums over the years, for example:

viewtopic.php?t=25930

and

viewtopic.php?t=29963

and a plugin, that I have not evaluated.

viewtopic.php?t=48807

and Least Squares

viewtopic.php?f=5&t=23758

[TheWitness]

Okay, after some discussion. Here is a draft plan with assignments.

1. First merge the special data source types from the Least Squares post into mainline (TheWitness - Complete)
2. Second add the HoltWinters Consolidation Functions to the core (TheWitness)
3. Provide Mock-Up for a dynamic interface where you can turn on/off Predictions in any Graph (Petr Macan)
4. Discuss Mock-Up and arrive at a plan that does not radically alter templates, but provides a way to scale up prediction using the Cacti Templating engine if possible. (TBD)
5. Perform raw development of agreed to interface (Petr Macan)

The first release of Forecasting add-on may just be the UI to do live predictions, and second pass to scale out that model. Of course, this post here is to foster the debate.

[TheWitness]

Looking at RAW HoltWinters, it looks like we would require a schema change. We have the following RRA's per the RRDtool documentation:

• RRA:HWPREDICT:rows:alpha:beta:seasonal period[:rra-num]
• RRA:MHWPREDICT:rows:alpha:beta:seasonal period[:rra-num]
• RRA:SEASONAL:seasonal period:gamma:rra-num[:smoothing-window=fraction]
• RRA:DEVSEASONAL:seasonal period:gamma:rra-num[:smoothing-window=fraction]
• RRA:DEVPREDICT:rows:rra-num
• RRA:FAILURES:rows:threshold:window length:rra-num

If we use the Structured SQL, we would need additional columns

• alpha - mandatory for HWPREDICT, MHWPREDICT
• beta - mandatory for HWPREDICT, MHWPREDICT
• seasonal period - mandatory for HWPREDICT, MHWPREDICT, SEASONAL, DEVSEASONAL
• gamma - mandatory for DEVSEASONAL
• smoothing_window - optional for SEASONAL, DEVSEASONAL
• threshold - mandatory for FAILURES
• window_length - mandatory for FAILURES

The RRA number looks like it's mandatory for all but HWPREDICT and MHWPREDICT.