tomcat_jvm

#!/usr/bin/perl
# -*- perl -*-

=head1 NAME

tomcat_jvm - Plugin to monitor the memory of the JVM in Tomcat
servers.

=head1 CONFIGURATION

The following environment variables are used by this plugin:

=over 4

=item timeout

Connection timeout

=item url

Override default status-url

=item port

HTTP port number

=item user

Manager username

=item password

Manager password

=back

=head1 USAGE

Needs access to http://<user>:<password>@localhost:8080/manager/status?XML=true (or modify the address for another host). 

Tomcat 7.0 or higher.

A munin-user in $CATALINA_HOME/conf/tomcat-users.xml should be set up for this to work.

Tip: To see if it's already set up correctly, just run this plugin with the parameter "autoconf". If you get a "yes", everything should work like a charm already.

tomcat-users.xml example:
 <user username="munin" password="<set this>" roles="manager-status"/>

=head1 AUTHOR

Rune Nordbøe Skillingstad <runesk@linpro.no>

=head1 LICENSE

GPLv2

=head1 MAGIC MARKERS

 #%# family=manual
 #%# capabilities=autoconf

=cut

use strict;

my $ret = undef;

if(!eval "require LWP::UserAgent;") {
    $ret = "LWP::UserAgent not found";
}

if(!eval "require XML::Simple;") {
    $ret .= "XML::Simple not found";
}

my $URL      = exists $ENV{'url'}      ? $ENV{'url'}      : "http://%s:%s\@%s:%d/manager/status?XML=true";
my $PORT     = exists $ENV{'port'}     ? $ENV{'port'}     : exists $ENV{'ports'} ? $ENV{'ports'} : 8080;
my $HOST     = exists $ENV{'host'}     ? $ENV{'host'}     : "127.0.0.1";
my $USER     = exists $ENV{'user'}     ? $ENV{'user'}     : "munin";
my $PASSWORD = exists $ENV{'password'} ? $ENV{'password'} : "munin";
my $TIMEOUT  = exists $ENV{'timeout'}  ? $ENV{'timeout'}  : 30;

my $url = sprintf $URL, $USER, $PASSWORD, $HOST, $PORT;

if(exists $ARGV[0] and $ARGV[0] eq "autoconf") {
    if($ret) {
	print "no ($ret)\n";
	exit 0;
    }
    my $au = LWP::UserAgent->new(timeout => $TIMEOUT);
    my $repsonse = $au->request(HTTP::Request->new('GET',$url));
    if($repsonse->is_success and $repsonse->content =~ /<status>.*<\/status>/im) {
	print "yes\n";
	exit 0;
    } else {
	print "no (no tomcat status)\n";
	exit 0;
    }
}

if(exists $ARGV[0] and $ARGV[0] eq "config") {
    print "graph_title Tomcat JVM memory\n";
    print "graph_args --base 1024 -l 0\n";
    print "graph_vlabel Bytes\n";
    print "graph_category tomcat\n";
    print "graph_order free used max\n";
    print "free.label free bytes\n";
    print "free.draw AREA\n";
    print "used.label used bytes \n";
    print "used.draw STACK\n";
    print "max.label maximum bytes\n";
    print "max.draw LINE2\n";
    exit 0;
}

my $ua = LWP::UserAgent->new(timeout => $TIMEOUT);
my $xs = new XML::Simple;
my $response = $ua->request(HTTP::Request->new('GET',$url));
my $xml = $xs->XMLin($response->content);

if($xml->{'jvm'}->{'memory'}->{'free'} && 
    $xml->{'jvm'}->{'memory'}->{'total'} &&
    $xml->{'jvm'}->{'memory'}->{'max'}) {
    print "free.value " . $xml->{'jvm'}->{'memory'}->{'free'} . "\n";
    print "used.value " . 
	  ($xml->{'jvm'}->{'memory'}->{'total'} - 
	      $xml->{'jvm'}->{'memory'}->{'free'}) . "\n";
    print "max.value " . $xml->{'jvm'}->{'memory'}->{'max'} . "\n";
} else {
    print "free.value U\n";
    print "used.value U\n";
    print "max.value U\n";
}

# vim:syntax=perl