/usr/share/munin/plugins/mysql_threads is in munin-node 1.4.6-3ubuntu3.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78  | #!/bin/sh
# -*- sh -*-
: << =cut
=head1 NAME
mysql_threads - Plugin to monitor the number of threads on a mysql-server.
=head1 CONFIGURATION
Configuration parameters for /etc/munin/mysql_threads, if you
need to override the defaults below:
 [mysql_threads]
  env.mysqlopts    - Options to pass to mysql
=head2 DEFAULT CONFIGURATION
 [mysql_threads]
  env.mysqlopts
=head1 AUTHOR
Unknown author
=head1 LICENSE
Unknown license
=head1 MAGIC MARKERS
=begin comment
These magic markers are used by munin-node-configure when installing
munin-node.
=end comment
 #%# family=manual
 #%# capabilities=autoconf
=cut
MYSQLOPTS="$mysqlopts"
MYSQLADMIN=${mysqladmin:-mysqladmin}
if [ "$1" = "autoconf" ]; then
        $MYSQLADMIN --version 2>/dev/null >/dev/null
        if [ $? -eq 0 ]
        then
                $MYSQLADMIN $MYSQLOPTS status 2>/dev/null >/dev/null
                if [ $? -eq 0 ]
                then
                        echo yes
                        exit 0
                else
                        echo "no (could not connect to mysql)"
                fi
        else
                echo "no (mysqladmin not found)"
        fi
        exit 0
fi
if [ "$1" = "config" ]; then
	echo 'graph_title MySQL threads'
	echo 'graph_vlabel threads'
	echo 'graph_category mysql'
	echo 'graph_info Note that this is a old plugin which is no longer installed by default.  It is retained for compatability with old installations.'
	
	echo 'threads.label mysql threads'
	echo 'graph_args --base 1000'
	exit 0
fi
/usr/bin/printf "threads.value "
($MYSQLADMIN $MYSQLOPTS status 2>/dev/null || echo 'a a a U') | awk '{print $4}'
 |