Munin contributed plugins

#! /usr/bin/perl

# Varnish cache hit ratio logger/plugin

# anders@fupp.net, 2007-09-19

# Log/data file

# These must have write permission to the user the plugin runs as

# On FreeBSD, that is nobody

# Comment $mylog out to skip logging

# Set to 1 if you want to show unknown requsts (client requests which are

# neither hits nor misses):

$showunknown = 1;

$mydat = "/var/tmp/varnish_cachehitratio.dat";

#$mylog = "/var/log/varnish_cachehitratio.log";

%stat = ();

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

open(VV, "varnishstat -V 2>&1 |");

while (<VV>) {

	if (/^varnishstat/) { $vversion = $_; }

}

close(VV);

chomp($vversion);

$vversion =~ s@varnishstat\s*@@;

$vversion =~ s@\(@@; 

$vversion =~ s@\)@@;

$vversion =~ s@varnish-@@;

use Date::Format;

sub popstat10 {

	foreach $line (`varnishstat -1`) {

	chomp($line);

		if ($line =~ /^\s+(\d+)\s+(.*)$/) {

			$val = $1;

			$key = $2;

			$key =~ s@\s@_@g;

			$key =~ tr@A-Z@a-z@;

			$stat{"$key"} = $val;

		}

	}

}

sub popstat {

	foreach $line (`varnishstat -1`) {

	chomp($line);

		if ($line =~ /^\w+\s+(\d+)\s+[\d\.]+\s+(.*)$/) {

			$val = $1;

			$key = $2;

			$key =~ s@\s@_@g;

			$key =~ tr@A-Z@a-z@;

			$stat{"$key"} = $val;

		}

	}

}

sub printconfig {

	print "graph_title Cache hit/miss ratio\n";

	print "graph_args --upper-limit 100 -l 0\n";

	print "graph_vlabel % of requests\n";

	print "graph_category varnish\n";

	print "graph_info This graph shows the ratio of requests found in the cache and not\n";

	if ($showunknown) {

		print "graph_order hitratio missratio unknownratio\n";

	} else {

		print "graph_order hitratio missratio\n";

	}

	print "graph_scale no\n";

	print "hitratio.label hits\n";

	print "hitratio.type GAUGE\n";

	print "hitratio.graph yes\n";

	print "hitratio.min 0\n";

	print "hitratio.max 100\n";

	print "hitratio.draw AREA\n";

	print "missratio.label misses\n";

	print "missratio.type GAUGE\n";

	print "missratio.graph yes\n";

	print "missratio.min 0\n";

	print "missratio.max 100\n";

	print "missratio.draw STACK\n";

	if ($showunknown) {

		print "unknownratio.label unknown\n";

		print "unknownratio.type GAUGE\n";

		print "unknownratio.graph yes\n";

		print "unknownratio.min 0\n";

		print "unknownratio.max 100\n";

		print "unknownratio.draw STACK\n";

	}

}

sub findvalues {

	$nrequests = (defined $stat{"client_requests_received"}) ? $stat{"client_requests_received"} : 0;

	$nhits = (defined $stat{"cache_hits"}) ? $stat{"cache_hits"} : 0;

	$nmisses = (defined $stat{"cache_misses"}) ? $stat{"cache_misses"} : 0;

	open(OVAL, $mydat);

	$tmpstr = <OVAL>;

	close(OVAL);

	chomp($tmpstr);

	($orequests,$ohits,$omisses) = split(/ /, $tmpstr, 3);

	$hits = $nhits - $ohits;

	$requests = $nrequests - $orequests;

	$misses = $nmisses - $omisses;

}

sub printvalues {

	if ($requests > 0) {

		$hitratio = sprintf("%.2f", $hits / $requests * 100);

		$missratio = sprintf("%.2f", $misses / $requests * 100);

	} else {

		# Assume cache hit ratio = 100% if requests < 0

		$hitratio = sprintf("%.2f", 100);

		$missratio = sprintf("%.2f", 0);

	}

	if ($hits > 0 || $misses > 0) {

		$xhitratio = sprintf("%.2f", $hits / ($hits+$misses)*100);

		$xmissratio = sprintf("%.2f", $misses / ($hits+$misses)*100);

	} else {

		$xhitratio = sprintf("%.2f", 100);

		$xmissratio = sprintf("%.2f", 0);

	}

	if (($hitratio + $missratio) > 100) {

		# Rounding foo, hit+miss ratio is higher than 100

		$missratio = sprintf("%.2f", 100 - $hitratio);

		$unknownratio = sprintf("%.2f", 0);

	} else {

		# Unknown = rest, hit+miss ratio is upto or 100

		$unknownratio = sprintf("%.2f", 100 - ($hitratio + $missratio));

	}

	if ($showunknown) {

		print "hitratio.value $hitratio\n";

	} else {

		print "hitratio.value $xhitratio\n";

	}

	print "missratio.value $missratio\n";

	if ($showunknown) {

		print "unknownratio.value $unknownratio\n";

	}

	if ($mylog ne "") {

		open(LOG, ">>$mylog");

		if ($showunknown) {

			print LOG "hitratio=$hitratio missratio=$missratio unknown=$unknownratio hits=$hits misses=$misses requests=$requests [" . time2str("%Y-%m-%d %H:%M:%S", time) . "]\n";

		} else {

			print LOG "hitratio=$hitratio missratio=$missratio hits=$hits misses=$misses requests=$requests [" . time2str("%Y-%m-%d %H:%M:%S", time) . "]\n";

		}

		close(LOG);

	}

}

sub writevalues {

	open(OVAL, ">$mydat");

	# xhitratio is hitratio considering only hits and misses, not client

	# requests

	print OVAL "$nrequests $nhits $nmisses $hitratio $xhitratio\n";

	close(OVAL);

}

if ($ARGV[0] eq "autoconf") {

	print "yes\n";

} elsif ($ARGV[0] eq "config") {

	printconfig;

} else {

	if ($vversion =~ /^1\.0/) {

		popstat10;

	} else {

		popstat;

	}

	findvalues;

	printvalues;

	writevalues;

}