diff options
| -rw-r--r-- | CHANGES | 2 | ||||
| -rw-r--r-- | lib/Smokeping/matchers/Median.pm | 3 | ||||
| -rw-r--r-- | lib/Smokeping/matchers/Medratio.pm | 118 |
3 files changed, 121 insertions, 2 deletions
@@ -1,3 +1,5 @@ +* new matcher Medratio (compare two medians) -- tobi +* fixes for Median matcher -- tobi * make the CGI not croak if a password file is not readable. -- niko * don't die if syslogd is dead -- niko, reported by Christoph Biedl <cbiedl *gmx.de> as Debian bug #395056 diff --git a/lib/Smokeping/matchers/Median.pm b/lib/Smokeping/matchers/Median.pm index 3c8560a..65d71e2 100644 --- a/lib/Smokeping/matchers/Median.pm +++ b/lib/Smokeping/matchers/Median.pm @@ -73,8 +73,7 @@ sub Test($$) my $ac = $self->{param}{old}; my $bc = $self->{param}{new}; my $cc = $ac +$bc; - my $oldm = (sort {$a <=> $b} @{$data->{rtt}}[-$cc..-$bc-1])[int($a/2)]; - $ac++; + my $oldm = (sort {$a <=> $b} @{$data->{rtt}}[-$cc..-$bc-1])[int($ac/2)]; my $newm = (sort {$a <=> $b} @{$data->{rtt}}[-$bc..-1])[int($bc/2)]; return abs($oldm-$newm) > $self->{param}{diff}; } diff --git a/lib/Smokeping/matchers/Medratio.pm b/lib/Smokeping/matchers/Medratio.pm new file mode 100644 index 0000000..e1a4449 --- /dev/null +++ b/lib/Smokeping/matchers/Medratio.pm @@ -0,0 +1,118 @@ +package Smokeping::matchers::Medratio; + +=head1 NAME + +Smokeping::matchers::Medratio - detect changes in the latency median + +=head1 OVERVIEW + +The Medratio matcher establishes a historic median latency over +several measurement rounds. It compares this median, against a second +median latency value again build over several rounds of measurement. + +By looking at the median value this matcher is largly imune against spikes +and will only react to long term developments. + +=head1 DESCRIPTION + +Call the matcher with the following sequence: + + type = matcher + pattern = Medratio(historic=>a,current=>b,comparator=>o,percentage=>p) + +=over + +=item historic + +The number of values to use for building the 'historic' median. + +=item current + +The number of values to use for building the 'current' median. + +=item comparator + +Which comparison operator should be used to compare current/historic with percentage. + +=item percentage + +Right hand side of the comparison. + +=back + + old <--- historic ---><--- current ---> now + +=head1 EXAMPLE + +Take the 12 last median values. Build the median out of the first 10 +and the median from the other 2 values. Divide the results and decide +if it is bigger than 150 percent. + + Medratio(historic=>10,current=>2,comparator=>'>',percentage=>150); + + med(current)/med(historic) > 150/100 + +This means the matcher will activate when the current latency median is +more than 1.5 times the historic latency median established over the last +10 rounds of measurement. + +=head1 COPYRIGHT + +Copyright (c) 2006 by OETIKER+PARTNER AG. All rights reserved. + +=head1 SPONSORSHIP + +The development of this matcher has been paied for by Virtela +Communications, L<http://www.virtela.net/>. + +=head1 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. + +=head1 AUTHOR + +Tobias Oetiker <tobi@oetiker.ch> + +=cut + +use vars qw($VERSION); + + +$VERSION = 1.0; + +use strict; +use base qw(Smokeping::matchers::Avgratio); +use Carp; + +sub Desc ($) { + croak "Detect changes in median latency"; +} + +sub Test($$) +{ my $self = shift; + my $data = shift; # @{$data->{rtt}} and @{$data->{loss}} + my $len = $self->Length; + my $rlen = scalar @{$data->{rtt}}; + return undef + if $rlen < $len + or (defined $data->{rtt}[-$len] and $data->{rtt}[-$len] eq 'S'); + my $ac = $self->{param}{historic}; + my $bc = $self->{param}{current}; + my $cc = $ac +$bc; + my $hm = (sort {$a <=> $b} @{$data->{rtt}}[-$cc..-$bc-1])[int($ac/2)]; + my $cm = (sort {$a <=> $b} @{$data->{rtt}}[-$bc..-1])[int($bc/2)]; + return undef unless $hm and $cm; + return &{$self->{param}{sub}}($cm/$hm,$self->{param}{value}); +} |