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>