The Graph definition is as follows:

[lighttpd]
TITLE lighttpd Requests/Second
YAXIS # reqs/sec
DEF:RPS=lighttpd.rrd:reqpersec:AVERAGE
LINE2:RPS#0000CC:reqs/sec
COMMENT:
GPRINT:RPS:LAST:Requests per Second   : %5.1lf (cur)
GPRINT:RPS:MAX: : %5.1lf (max)
GPRINT:RPS:MIN: : %5.1lf (min)
GPRINT:RPS:AVERAGE: : %5.1lf (avg)

The Xymon scripts source code is:

#!/usr/bin/perl -w
#############################################################################
# $Id: mi-lighttpd.pl 21 2009-05-07 19:22:28Z rar $
#############################################################################

use strict;
use File::Slurp;
use LWP::Simple;
use Data::Dumper;

my $port = 80;
my $bbtest = 'lighttpd';

#############################################################################
## BB and related test constants
#############################################################################

use constant CLEAR  => 'clear';
use constant GREEN =>  'green';
use constant YELLOW => 'yellow';
use constant RED    => 'red';
use constant PURPLE => 'purple';

{

#############################################################################
## Setup Variables
#############################################################################
	my $DATA    = "";
	my $color   = GREEN;
	my $status  = $bbtest . " OK";
	my $previous_run;
	my $current_run;
	my $restarted   = 0;
	my @delta_tests = ( 'total_kbytes', 'total_accesses', 'uptime' );
	my @counter_tests   = ( 'total_accesses', 'total_kbytes', 'uptime', 'reqpersec' );
	my @write_log;
	my $backup_log    = "$ENV{BBTMP}/$ENV{MACHINE}.lighttpd.data";
	my %lighttpd_states = (
		'_' => 'awaiting_conn',
		'.' => 'connect',
		'r' => 'reading_req',
		'R' => 'reading_req_post',
		's' => 'sending_reply',
		'S' => 'sending_reply_end',
		'q' => 'request_start',
		'Q' => 'request_end',
		'W' => 'write',
		'h' => 'handle_request',
		'C' => 'close',
		'E' => 'hard_error',
	);
	my %error_states = (
		'reqpersec' => '100',
		'sending_reply' => '100'
	);

	my %warn_states = (
		'reqpersec' => '75',
		'sending_reply' => '75'
	);

#############################################################################
## Gather previous run data & current data
#############################################################################

	# Get Last Status
	if ( -e $backup_log ) {

		#Split Apart Data
		my @data = read_file($backup_log);
		if (@data) {
			foreach my $line (@data) {
				chomp($line);
				my ( $key, $value ) = split( /=/, $line, 2 );
				$previous_run->{$key} = $value;
			}
		}
		else {
			$previous_run = 0;
		}
	}

	my $status_data = get "http://localhost:$port/server-status?auto";

#############################################################################
## Munge the data up to get what we want
#############################################################################

	if ( defined($status_data) ) {

		my @data = split( /n/, $status_data );
		foreach my $line (@data) {
			chomp($line);
			my ( $key, $value ) = split( /: /, $line );
			$key =~ s/ /_/g;
			$key = lc($key);
			$current_run->{$key} = $value;
		}

		# Create array of new values to save for our next run
		foreach ( keys %{$current_run} ) {
			push @write_log, "$_=$current_run->{$_}n";
		}

		# Calculate Incremental Data
		if ($previous_run) {
			# We need to check if we restarted here to avoid negitives
			if ($current_run->{uptime} > $previous_run->{uptime} ){
				foreach (@delta_tests) {
						$current_run->{$_} = $current_run->{$_} - $previous_run->{$_};
				}
			}
			else {
				$status = $bbtest . " Restarted";
				$color = YELLOW;
				$restarted = 1;
			}
		}

		# Break out scoreboard data
		foreach ( keys %lighttpd_states ) {
			$current_run->{ $lighttpd_states{$_} } = 0;
		}
		foreach ( split( //, $current_run->{scoreboard} ) ) {
			$current_run->{ $lighttpd_states{$_} }++;
		}

		if ( !$restarted ) {
			# Get Req/Sec since last check
			$current_run->{reqpersec} = sprintf "%.2F", ( $current_run->{total_accesses} / $current_run->{uptime} ) if $current_run->{uptime};

			## save our counter tests for the next run incase we
			## lighttpd gets restarted we have some non-zero data to send in
			foreach (@counter_tests) {
				push @write_log, "cur_$_=$current_run->{$_}n";
			}    

			# Check for warning states
			foreach ( keys %warn_states ) {
				if ( $current_run->{$_} > $warn_states{$_} ) {
					$color  = YELLOW;
					$status = $bbtest . " $_ > $warn_states{$_}";
				}
			}

			# Check for error states
			foreach ( keys %error_states ) {
				if ( $current_run->{$_} > $error_states{$_} ) {
					$color  = RED;
					$status = $bbtest . " $_ > $error_states{$_}";
				}
			}
		}
		else {
			## So we restarted, and we don't want to send nothing
			## and we don't want to send negitives on calculated tests
			## since we saved them last run for this purpose, we'll send in
			## our last run stats to keep from having huge drops in the
			## graphs.
			foreach (@counter_tests) {
				$current_run->{$_} = sprintf "%.2F", $previous_run->{ "cur_".$_ };
			}
		}

		# Delete Some Unwanted Data
		delete $current_run->{scoreboard};
		delete $current_run->{uptime};

		# Create Hobbit Data
		foreach ( sort keys %{$current_run} ) {
			$DATA .= "$_:$current_run->{$_}n";
		}

		# Actually Write last run file
		write_file( $backup_log, @write_log );

	}
	else {
		$status = $bbtest . " unable to get server-status";
		$color  = CLEAR;
	}

#############################################################################
## Give data to hobbit
#############################################################################

	# hobbit formatted output
	my $report_date = `/bin/date`;
	chomp($report_date);

	## DEV DEBUG
	#print "$ENV{BB} $ENV{BBDISP} 'status apollo,xipnet,net.$bbtest $color $report_date - $statusnn$DATA'n";
	system("$ENV{BB} $ENV{BBDISP} 'status apollo,xipnet,net.$bbtest $color $report_date - $statusnn$DATA'n");
}