#!/usr/bin/perl -Tw

# Plugin to monitor ZEO connected clients, reads, writes and errors/conflicts
#
# Author: Terry Burton <tez@terryburton.co.uk>
#
# Revisions:
#
# 1.0  2010/07/08  First version
# 1.1  2010/07/09  Split load into reads and writes
#                  Reads has logarithmic scale
#                  Adjust some scaling factors
#                  Support for INET connections, the new default
# 
# Invoke using symlinks to zeo_monitor_ in the form zeo_monitor_{clients,reads,writes,errors}_<storage_name>
#
# This plugin can be configured manually or by autoconf (provided that the ZEO
# monitor runs on the default port 8091.)
#
# root@munin:~ munin-node-configure --shell
# ln -s /usr/share/munin/plugins/zeo_monitor_ /etc/munin/plugins/zeo_monitor_clients_1
# ln -s /usr/share/munin/plugins/zeo_monitor_ /etc/munin/plugins/zeo_monitor_clients_temp
# ln -s /usr/share/munin/plugins/zeo_monitor_ /etc/munin/plugins/zeo_monitor_errors_1
# ln -s /usr/share/munin/plugins/zeo_monitor_ /etc/munin/plugins/zeo_monitor_errors_temp
# ln -s /usr/share/munin/plugins/zeo_monitor_ /etc/munin/plugins/zeo_monitor_reads_1
# ln -s /usr/share/munin/plugins/zeo_monitor_ /etc/munin/plugins/zeo_monitor_reads_temp
# ln -s /usr/share/munin/plugins/zeo_monitor_ /etc/munin/plugins/zeo_monitor_writes_1
# ln -s /usr/share/munin/plugins/zeo_monitor_ /etc/munin/plugins/zeo_monitor_writes_temp
#  
#
# Configuration variables:
#
#       zeomonitoraddr - address:port of the zeo monitor server socket (default 127.0.0.1:8091)
#       zeomonitorsock - path to the zeo monitor server socket
#
#   Note: This plugin will attempt to attach to the network socket given by
#         zeomonitoraddr unless the path to a Unix domain socket is given with
#         zeomonitorsock
#
# Parameters:
#
#       config
#       autoconf
#       suggest
#
# Configuration examples:
#
#   Connect to the monitor server running on TCP/4567
#
#       [zeo_monitor_*]
#       user root
#       env.zeomonitoraddr 127.0.0.1:4567
#
#   Connect to the monitor server running on a Unix domain socket
#
#       [zeo_monitor_*]
#       user root
#       env.zeomonitorsock /var/run/zeo/zeo-monitor.sock
#
# Magic markers (optional - used by munin-config and installation
# scripts):
#
#%# family=auto
#%# capabilities=autoconf suggest

use strict;

# Need to use eval EXPR here. "-T" is used on the command line, and
# munin is not installable in a reasonable way for automated testing.
eval 'use Munin::Plugin; 1;' or die 'Please install Munin::Plugin';

use File::Basename;
use IO::Socket::UNIX qw(SOCK_STREAM);

my $zeomonitoraddr = exists $ENV{'zeomonitoraddr'} ? $ENV{'zeomonitoraddr'} : '127.0.0.1:8091';
($zeomonitoraddr)=$zeomonitoraddr=~/(.*)/;
my $zeomonitorsock = exists $ENV{'zeomonitorsock'} ? $ENV{'zeomonitorsock'} : '';
($zeomonitorsock)=$zeomonitorsock=~/(.*)/;

if (basename($0) !~ /^zeo_monitor_/) {
    die qq(Please ensure that the name of the script and it's symlinks starts with "zeo_monitor_"\n);
}


############
# autoconf #
############

if (defined $ARGV[0] && $ARGV[0] eq 'autoconf') {

    # Capture any croaks on the way

    eval { parse_zeo_monitor(); };

    if ( !$@ ) {
        print "yes\n";
        exit 0;
    }

    chomp $@;
    print "no ($@)\n";
    exit 0;

}


###########
# suggest #
###########

if (defined $ARGV[0] and $ARGV[0] eq 'suggest') {

    my @storage_names;

    eval { @storage_names=parse_zeo_monitor(); };
    exit 0 if ( $@ );

    print "clients_$_\nreads_$_\nwrites_$_\nerrors_$_\n" foreach @storage_names;
    exit 0;

}


# From now on we require the mode and storage name to be given
(my $mode,my $storage_name)=$0=~/zeo_monitor_(.+)_(.+)$/;
die qq(Symlink to this script by appending a mode and storage name such as "zeo_monitor_load_temp"\n) unless defined $storage_name;


##########
# config #
##########

if ( $ARGV[0] and $ARGV[0] eq "config") {
  
  print <<"EOF";
graph_title ZEO $mode for storage $storage_name
graph_args --base 1000 --lower-limit 0
graph_vlabel events per \${graph_period}
graph_category zeo
graph_info ZEO performance monitoring
EOF

if ($mode eq 'clients') {
  print <<EOF;
clients.label Clients
clients.type GAUGE
EOF
}

if ($mode eq 'reads') {
  print <<EOF;
graph_args --logarithmic --lower-limit 1
loads.label Loads
loads.type DERIVE
loads.min 0
EOF
}

if ($mode eq 'writes') {
  print <<EOF;
commits.label Commits (x10)
commits.type DERIVE
commits.min 0
commits.cdef commits,10,*
stores.label Stores
stores.type DERIVE
stores.min 0
EOF
}

if ($mode eq 'errors') {
  print <<EOF;
aborts.label Aborts (x10)
aborts.type DERIVE
aborts.min 0
aborts.cdef aborts,10,*
conflicts.label Conflicts (x10)
conflicts.type DERIVE
conflicts.min 0
conflicts.cdef conflicts,10,*
conflictsres.label Conflicts Resolved
conflictsres.type DERIVE
conflictsres.min 0
EOF
}

  exit 0;

}


########
# main #
########

my %stats=parse_zeo_monitor($storage_name);

if ($mode eq 'clients') {
  print <<"EOF";
clients.value $stats{clients}
EOF
}

if ($mode eq 'reads') {
  print <<"EOF";
loads.value $stats{loads}
EOF
}

if ($mode eq 'writes') {
  print <<"EOF";
commits.value $stats{commits}
stores.value $stats{stores}
EOF
}

if ($mode eq 'errors') {
  print <<"EOF";
aborts.value $stats{aborts}
conflicts.value $stats{conflicts}
conflictsres.value $stats{conflictsres}
EOF
}

exit 0;


####

# Read the zeo-monitor socket and parse the result. If a storage name is given
# then return the stats for it. Otherwise return a list of available storage
# names.

sub parse_zeo_monitor {

  my $storage_name=shift;

  my $socket;
  if ($zeomonitorsock ne '') {
    $socket=IO::Socket::UNIX->new(Type=>SOCK_STREAM,Peer=>$zeomonitorsock) or die("Can't connect to socket: $!\n");
  } else {
    $socket=IO::Socket::INET->new(Proto=>"tcp",PeerAddr=>$zeomonitoraddr) or die("Can't connect to port: $!\n");
  }
  my $response=join('',<$socket>);
  close $socket;

  # If no storage name is given then return list of all storage names
  if (!defined $storage_name) {
    return map {/: (.*)/} (grep /^Storage: /, split(/\n/,$response));
  }

  # Otherwise, read the stats for the given storage name
  (my $stats)=$response=~/
    (
      Storage:\ $storage_name\n
      .*?
      \n
    )
    \n
  /sx;
  
  my %name_var=(
    'Clients'               => 'clients',
    'Commits'               => 'commits',
    'Aborts'                => 'aborts',
    'Loads'                 => 'loads',
    'Stores'                => 'stores',
    'Conflicts'             => 'conflicts',
    'Conflicts resolved'    => 'conflictsres',
  );
  
  my %stats=();
  foreach (split /\n/, $stats) {
    (my $name,my $value)=split ': ',$_,2;
    my $var=$name_var{$name};
    next unless $var;
    $stats{$var}=$value;
  }
  
  return %stats;

}