NAME

       Smokeping::matchers::Median - Find persistant changes in latency

OVERVIEW

       The idea behind this matcher is to find sustained changes in latency.

       The median matcher takes a number of past median latencies. It splits the latencies into
       two groups (old and new) and again finds the median for each groups. If the difference
       between the two medians is bigger than a certain value, it will give a match.

DESCRIPTION

       Call the matcher with the following sequence:

        type = matcher
        pattern =  Median(old=>x,new=>y,diff=>z)

       This will create a matcher which consumes x+y latency-datapoints, builds the two medians
       and the matches if the difference between the median latency is larger than z seconds.

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>