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.
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>