Predictive Threshold

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VERSION 8

Created on: Sep 14, 2009 1:32 PM by rocketman110 - Last Modified: Oct 15, 2012 1:56 PM by Ryan Matte

Submitted by:

Eric J. Edgar

Updated by:

Jane Curry

Description:

This ZenPack adds a new Predictive Threshold type for determining when to trigger an event. The threshold uses the Holt-Winters Forecasting from RRDTool.

Retrofitting data exists in the Predictive Threshold. It renames the original .rrd with a .old extension. The RemoveHoltData.py script packaged with the ZenPack is a command line tool for converting RRD data back to regular RRD files if you want to convert them back to standard thresholds.

Holt Winters Parameters

Alpha = 0.1 # 0-1 , value closer to 1 means more recent observation carries more weight, baseline
Beta = 0.0035 # 0-1 , value closer to 1 means more recent observation carries more weight, linear trend
Gamma = 0.1 # 0-1 , value closer to 1 means more recent observation carries more weight, seasonal trend
Rows = 1440 # rows >=season, 5days, 300second_intervals * 1440 points
Season = 288 # 1day, 288points * 300second_intervals
Window = 6 # window length .. (eg 6 observations for alerting)
Threshold = 3 # number of periods it has to fail in a window before alert sent
Delta = 2 # of standard deviations away from predicted value (for alerting)
Prediction Color = Color of the predicted value line
Confidence Band Color = Color of the confidence bands placed at delta standard deviations from prediction line
Tick Color = color of vertical line indicating threshold has been crossed at that value

Screenshots: