This is a wildcard plugin that takes the name of a MySQL slave status variable, and plots it.

The MySQL manual says what the variables mean.

To use it, append the name of a slave status variable -- "mv mysql_slave_status_ mysql_slave_status_seconds_behind_master".

#!/usr/bin/perl

use strict;
use warnings;

use File::Basename;

my $variable = basename $0;
$variable =~ s/^mysql_slave_status_//;
$variable or die "no variable";

if ($ARGV[0] && $ARGV[0] eq 'config') {
   print <<END;
graph_title MySQL $variable
graph_vlabel $variable
$variable.label $variable
END

   exit;
}

open(MYSQL, '/usr/bin/mysql --batch -e "show slave status" |') or die $!;

chomp (my $keys = lc <MYSQL>);
my @keys = split /\t/, $keys;

chomp (my $values = <MYSQL>);
my @values = split /\t/, $values;

my %hash;
@hash{@keys} = @values;

if (defined $hash{$variable}) {
   printf("%s.value %d\n", $variable, $hash{$variable});
}