---
name: "Smokeping::matchers::Avgratio"
section: "3"
platform: "linux"
package: "smokeping"
version: "2.3.6-5+squeeze1"
release: "Debian 6.0 (Squeeze)"
platforms: ["linux"]
url: "https://new.carta.tech/Smokeping::matchers::Avgratio"
---

# Smokeping::matchers::Avgratio(3)

detect changes in average median latency

## NAME

Smokeping::matchers::Avgratio - detect changes in average median latency

## OVERVIEW

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

## DESCRIPTION

Call the matcher with the following sequence:

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

- historic

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

- current

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

- comparator

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

- percentage

  Right hand side of the comparison.

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

## EXAMPLE

Take build the average median latency over 10 samples, use this to divide the current average latency built over 2 samples and check if it is bigger than 150%.

```
 Avgratio(historic=>10,current=>2,comparator=>'>',percentage=>150);
 avg(current)/avg(historic) > 150/100
```

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

## COPYRIGHT

Copyright (c) 2004 by OETIKER+PARTNER AG. All rights reserved.

## SPONSORSHIP

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

## LICENSE

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

## AUTHOR

Tobias Oetiker \<tobi@oetiker.ch\>