Munin contributed plugins

#!/usr/bin/perl -w

#

# xen_cpu_v2.pl 1.00

# Script to minitor the CPU usage of Xen domains

# Zoltan HERPAI (c) 2009, wigyori@uid0.hu

#

# Based loosely on Adam Crews' xen_cpu script

#

# This script tries to measure the CPU usage of the Xen guests

# accurately. 

# The problem with the current monitoring script is that these 

# scripts use the CPU output of xentop or xm list, which might be

# inaccurate due to the resources used up at the time of the query by

# the xm or xentop command.

#

# This script stores the previous value of the CPU sec value of the given

# guests in a tempfile, then does some simple calculations to get the real

# CPU usage percentage of the guests.

#

#%# family=auto

#%# capabilities=autoconf

use strict;

use POSIX;

# Define where to find xm tools

my $XM = '/usr/sbin/xm';

my $XMTOP = '/usr/sbin/xentop';

my $curtime = time();

my $basename = `/usr/bin/basename $0`; chop ($basename);

my $TEMPFILE = "/tmp/$basename";

my $debug = 0;

##############

# You should not need to edit anything below here

#

$ENV{PATH} = '/bin:/usr/bin:/usr/sbin';

my $arg;

if ( defined($ARGV[0]) )

{

	if ( $ARGV[0] eq 'config' )

	{

		$arg = 'config';

	}

	if ( $ARGV[0] eq 'autoconf' )

	{

		$arg = 'autoconf';

	}

	if ( $arg eq 'autoconf')

	{

		if ( -e $XM && -e $XMTOP )

		{

			print "yes\n";

			exit 0;

		}

		else

		{

			print "no ($XM and/or $XMTOP not found\n";

			exit 1;

		}

	}

	if ( $arg eq 'config' )

	{

		my %cnf;

		%cnf = (

			'graph_title' => 'Xen Domain CPU Usage v2',

			'graph_args' => '--base 1000 -l 0 --upper-limit 100 --rigid',

			'graph_vlabel' => 'Percent (%)',

			'graph_category' => 'xen',

			'graph_info' => 'Display the % of CPU Usage for each domain',

		);

		my @domains = `$XM list`;

		my $cnt = 0;

		shift(@domains); # we dont need the header line

		foreach my $domain ( @domains )

		{

			my ($dom,undef) = split(/\s/, $domain, 2);

			$dom =~ s/[-.]/_/g;

			$cnf{ "$dom" . '.label' } = "$dom";

			$cnf{ "$dom" . '.draw' } = 'STACK';

			$cnf{ "$dom" . '.min' } = '0';

			$cnf{ "$dom" . '.max' } = '100';

			$cnf{ "$dom" . '.info' } = '% CPU used for ' . "$dom";

#			$cnf{ "$dom" . '.draw' } = 'AREA';

			if ( $cnt == 0 )

			{

				$cnf{ "$dom" . '.draw' } = 'AREA';

			}

			$cnt++;

		}

		foreach my $key (sort(keys(%cnf)))

		{

			print "$key $cnf{$key}\n";

		}

		exit 0;

	}

}

my @xmlist = `$XM list`;

shift (@xmlist);

my %dom; my $name; my $oldtime;

# Read old data

if ( -e $TEMPFILE )

{

	open(FH, "<", $TEMPFILE) or die $!;

	$oldtime = <FH>;

	if ( $debug )

	{

		print "Oldtime: $oldtime\n";

	}

	while (<FH>)

	{

		# Get the guest name and its CPU usage, and store it in $dom

		$_ =~ /(\S+)\s+\S+\s+\S+\s+\d+\s+\S+\s+(\S+)/;

		$dom{$1}->{'oldtime'} = $2;

	}

	close FH;

}

my $diff; my $cpusum = 0;

foreach my $domain ( @xmlist )

{

	# Get the domains' name and current CPU usage, store it in $dom

	$domain =~ /(\S+)\s+\S+\s+\S+\s+\d+\s+\S+\s+(\S+)/;

	$dom{$1}->{'newtime'} = $2;

	$diff = $dom{$1}->{'newtime'} - $dom{$1}->{'oldtime'};

	$diff = sprintf("%.2f", $diff);

	# Calc the diff between old and new cputime, or reset the counter

	if ( $diff < 0 )

	{

		$diff = $dom{$1}->{'newtime'};

	}

	$dom{$1}->{'diff'} = $diff;

	# Calc a sum CPU usage

	$cpusum = $cpusum + $diff;

}

my $numcpus = `$XM info |grep nr_cpus |cut -d \: -f 2`;

my $timediff = $curtime - $oldtime;

my $tcpuavail = $numcpus * $timediff;

if ( $debug )

{

	print "UsedCPUtime sum: $cpusum\n";

	print "CPUs: $numcpus\n";

	print "Timediff: $timediff\n";

	print "Total CPU time available: $tcpuavail\n";

}

my $key; my $value;

while (($key, $value) = each %dom)

{

	# Calc a percentage based on the used CPU time sum

	my $tmp = 0;

	$tmp = ( $dom{$key}->{'diff'} / $cpusum ) * 100;

	$dom{$key}->{'pc_time'} = sprintf("%.2f", $tmp);

	# Calc a percentage based on the _total_ available CPU time

	$tmp = 0;

	$tmp = ( $dom{$key}->{'diff'} / $tcpuavail ) * 100;

	$dom{$key}->{'pc_tcpu'} = sprintf("%.2f", $tmp);

	if ( $debug )

	{

		print "$key newtime: ".$dom{$key}->{'newtime'}.", oldtime: ".$dom{$key}->{'oldtime'}.", diff: ".$dom{$key}->{'diff'}.", pc_bytime ".$dom{$key}->{'pc_time'}.", pc_bytcpu ".$dom{$key}->{'pc_tcpu'}."\n";

	}

	print "$key.value ".$dom{$key}->{'pc_tcpu'}."\n";

}

# We'll need to log out the current "xm list" output, and the current time also.

open(FH, ">", $TEMPFILE) or die $!;

print FH $curtime."\n";

print FH @xmlist;

close FH;