#!/usr/bin/perl
# $Id: netconncnt,v 1.3 2007/06/07 21:29:16 cos Exp $
#
# Count web TCP connections in each state, and feed to ganglia
# Run this from cron as often as you want to sample; once/min:
# * * * * * /usr/local/bin/netconncnt
#
# Requires that ganglia-gmond is installed, gmond is running,
# and gmetric is in the path of whatever user runs this script.
# 
# Contributions/suggestions/bugs to: Ofer Inbar <cos@aaaaa.org>
#
# Written at, and donated to the community by, Going.com
# All my scripts distributed under the terms of Larry Wall's excellent
# Artistic License:  http://language.perl.com/misc/Artistic.html


$netstat = "netstat -n -t";
$filter = ":80";

# tcp        0      0 192.168.1.6:56351           192.168.1.2:11211           ESTABLISHED 

%statecount = (
  'CLOSING' => 0,
  'CLOSE_WAIT' => 0,
  'TIME_WAIT' => 0,
  'ESTABLISHED' => 0,
  'FIN_WAIT1' => 0,
  'FIN_WAIT2' => 0,
  'SYN_SENT' => 0,
  'SYN_RECV' => 0,
  'LAST_ACK' => 0
  );

# sleep a random few seconds so we don't count other monitoring scripts
sleep(rand(30));
open NETSTAT, "$netstat |"
    or die "$0: can't run $netstat: $!\n";

<NETSTAT>; <NETSTAT>;

while (<NETSTAT>)
{ my ($src,$dest,$state) = /^tcp\s+\d+\s+\d+\s+(\d\S+)\s+(\d\S+)\s+(\w+)/
      or warn "$0: can't parse $_" and next;
  next unless ($src =~ /$filter/);

  defined($statecount{$state})
      or warn "$0: unknown state: '$state' in $_" and next;
  $statecount{$state}++;
}

foreach $state (keys %statecount)
{ my $metric = "net_port80_" . lc($state);
  my $gmetric = "gmetric --name $metric --value $statecount{$state} --type uint8 --units 'connections'";
  # print "$gmetric\n";
  system($gmetric) and warn "$0: can't run gmetric: $?\n";
 }