Calculate Average Middleware Source

telem.middleware.calcAvg (windowSize?: integer)

Calculates the average of each metric in a collection, observed over a number of cycles. Each average is appended to the collection as a new metric, with an _avg suffix appended to the name, and the source set to middleware.

Name	Type	Default
windowSize	integer	50
Number of cycles to include when calculating the average.

Methods

force

CalcAverageMiddleware:force (): self

Force the middleware to process metrics from other middleware (source = 'middleware'), default is to ignore metrics from other middleware.

Usage

local telem = require 'telem'
local mw = telem.middleware

local backplane = telem.backplane()
  :addInput('random', telem.input.custom(function ()
    return { rand = math.random(1, 2) }
  end))
  :middleware(mw.calcAvg())
  :cycleEvery(0.1)()

This will result in the following collection:

Name	Value	Unit	Adapter	Source
rand	1 or 2		random
rand_avg	~ 1.5			middleware

Observing the value over time shows that the average converges to the expected value: