smokeping_matchers_avgratio(3) [debian man page]

..::lib::Smokeping::matchers::Avgratio(3)			     SmokePing				 ..::lib::Smokeping::matchers::Avgratio(3)

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>

2.6.8								    2012-02-26				 ..::lib::Smokeping::matchers::Avgratio(3)

..::lib::Smokeping::matchers::base(3)				     SmokePing				     ..::lib::Smokeping::matchers::base(3)

NAME

       Smokeping::matchers::base - Base Class for implementing SmokePing Matchers

OVERVIEW

       This is the base class for writing SmokePing matchers. Every matcher must inherit from the base class and provide it's own methods for the
       'business' logic.

       Note that the actual matchers must have at least one capital letter in their name, to differentiate them from the base class(es).

DESCRIPTION

       Every matcher must provide the following methods:

   new
       The new method expects hash elements as an argument eg new({x=>'d+',y=>'d+'},x=>1,y=>2). The first part is a syntax rule for the
       arguments it should expect and the second part are the arguments itself. The first part will be supplied by the child class as it calls the
       parent method.

   Length
       The Length method returns the number of values the matcher will expect from SmokePing. This method must be overridden by the children of
       the base class.

   Desc
       Simply return the description of the function. This method must be overwritten by a children of the base class.

   Test
       Run the matcher and return true or false. The Test method is called with a hash containing two arrays giving it access to both rtt and loss
       values.

	 my $data=shift;
	 my @rtt = @{$data->{rtt}};
	 my @loss = @{$data->{loss}};

       The arrays are ordered from old to new.

	 @rdd[old..new]

       There may be more than the expected number of elements in this array. Address them with $x[-1] to $x[-max].

       There's also a key called 'prevmatch' in the hash. It contains the value returned by the previous call of the 'Test' method. This allows
       for somewhat more intelligent alerting due to state awareness.

	 my $prevmatch = $data->{prevmatch};

COPYRIGHT

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

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>

2.6.8								    2012-02-26				     ..::lib::Smokeping::matchers::base(3)