NAME

       Smokeping::sorters::base - Base Class for implementing SmokePing Sorters

OVERVIEW

       Sorters are at the core of the SmokePing Charts feature, where the most interesting graphs are presented
       on a single page. The Sorter decides which graphs are considered interesting.

       Every sorter must inherit from the base class and provide it's own methods for the 'business' logic.

       In order to maintain a decent performance the sorters activity is split into two parts.

       The first part is active while the smokeping daemon gathers its data.  Whenever data is received, the
       sorter is called to calculate a 'value' for the present data. On every 'query round' this information is
       stored in the sorter store directory. Each smokeping process stores it's own information.  Since
       smokeping can run in multiple instances at the same time, the data may be split over several files

       The second part of the sorter is called from smokeping.cgi. It loads all the information from the sorter
       store and integrates it into a single 'tree'. It then calls each sorter with the pre-calculated data to
       get it sorted and to and to select the interesting information.

DESCRIPTION

       Every sorter 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.

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

   SortTree
       Returns an array of 'targets'. It is up to the sorter to decide how many entries the list should contain.
       If the list is empty, the whole entry will be suppressed in the webfrontend.

       The method gets access to all the targets in the system, together with the last data set acquired for
       each target.

   CalcValues
       Figure out the current sorting value using te following input.

        $info = { uptime => w,
                  loss   => x,
                  median => y,
                  alert  => z, # (0/1)
                  pings  => [qw(a b c d)] }

       The output can have any structure you want. It will be returned to the sorter method for further
       processing.

COPYRIGHT

       Copyright (c) 2007 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>