Prediction Framework

A prediction unit, or a forecast unit, refers to an executable, say my_regression_model.sh, that must be named $PWD/future_models/my_regression_model.sh, where $PWD is the working directory where habbix is run.

Input

These units are invoked by habbix sync. In stdin, the unit receives a JSON object (dubbed as an Event):

{ "value_type" : 0               // items.value_type (usually 0 or 3)
, "clocks" : [<epochs>]          // list of epoch times (x values)
, "values" : [<values>]          // y values
, "last"   : [<epoch>,<value>]   // (time, value) of last tick in history
, "draw_future" : [<epochs>]     // Requested value of "clocks"
, "params" :
  { "stop_lower": <epoch>        // start of prediction range (negative
                                 // units relative to current time) (optional)
  , "stop_upper": <epoch>        // End of prediction range in data (optional) 
  , "predict_length": <days>     // User's requested length for predictions
                                    (saved in DB) (if null, default: one week)
  , ...                          // Extra forecast-unit specific params (optional)
  }
}

Additionally, the name of the model is passed as the first command line parameter.

Output

In exchange, another JSON object (dubbed Result) is expected in the stdout:

{ "clocks"  : [<epochs>]         // Extrapolated clock-value pairs
, "values"  : [...]
, "details" : {<obj>}            // Forecast-specific details (R^2 etc.), Format is free
}

These (clocks, values) are inserted to the future of the original item.

clocks is a list of epoch timestamps (numbers). values are also numbers (unsigned integers if value_type == 3, decimals with a precision of 4 (.1234) if value_type == 0).

stderr is ignored.

Add predictions to habbix

habbix configure -e <file> registers the file future_models/<file> as a prediction unit and assigns it a model id.

habbix models lists all registered models.

habbix configure -i itemid -m <model>

habbix sync --syncall adds default item_futures to every item that does not have any with some rndm modelid taken from the model table (after syncing other zabbix tables to local db). Obviously adding the futures fails if no model had been registered. (the tables are copied though).

Run predictions

habbix execute -p '{...}' <n>

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