Smokeping_matchers_Medratio3

Overview

The Medratio matcher establishes a historic median latency over several measurement rounds. It compares this median, against a second median latency value again build over several rounds of measurement.

By looking at the median value this matcher is largely immune against spikes and will only react to long term developments.

Overview

Call the matcher with the following sequence:

 type = matcher
 pattern =  Medratio(historic=>a,current=>b,comparator=>o,percentage=>p)

historic

The number of values to use for building the 'historic' median.

current

The number of values to use for building the 'current' median.

comparator

Which comparison operator should be used to compare current/historic with percentage.

percentage

Right hand side of the comparison.

  old <--- historic ---><--- current ---> now

Examples

Take the 12 last median values. Build the median out of the first 10 and the median from the other 2 values. Divide the results and decide if it is bigger than 150 percent.

 Medratio(historic=>10,current=>2,comparator=>'>',percentage=>150);
 med(current)/med(historic) > 150/100

This means the matcher will activate when the current latency median is more than 1.5 times the historic latency median established over the last 10 rounds of measurement.

Sponsorship

The development of this matcher has been paid for by Virtela Communications, <http://www.virtela.net/>.