#!/usr/bin/perl -w

# gangliahack.pl (c) 18.sep.2003 Antti.Vanne@uku.fi
# Description:
# Quick hack to use ganglia in a cluster with a non-multicasting
# switch. Doesn't scale too well, usable on a 24 cluster though.
# Idea: listen to port $serverPort (8666 as default) for gmetad's
# request for XML data and when connected, gather XML from
# individual nodes from port $queryPort and serve it to gmetad.

# modified 26.03.2004: new header is created every time, otherwise
# the new version of ganglia complains about the non-updated
# cluster local time
#

use strict;
use IO::Socket::INET;

sub getHeader {
  my @argv = @_; 
  my $host = $argv[0];
  my $port = $argv[1];
  my $header; 

  my $remote = new IO::Socket::INET(
				    Proto => "tcp",
				    Timeout => "5",
				    PeerAddr => $host,
				    PeerPort => $port,
				   );

  if ($remote) {
    while (<$remote>) {
      $header .= $_;
      last if (/CLUSTER NAME="Klunga"/); # modify this as needed
    }
  }
  close $remote;
  return $header; 
}

sub getNodeInfo {
  my @argv = @_;
  my $host = $argv[0]; 
  my $port = $argv[1];
  my $nodeInfo;
  
  my $remote = new IO::Socket::INET(
				    Proto => "tcp",
				    Timeout => "5",
				    PeerAddr => $host,
				    PeerPort => $port,
				   );
  
  my $found = 0;
  if ($remote) {
    while (<$remote>) {
      if (/HOST NAME="$host"/) {
	$found = 1;
      };
      if ($found) {
	$nodeInfo .= $_;
      }
      last if ($found && /<\/HOST>/);
    }
    
    close $remote;
  }
  if (!$remote) {
    print "Error in fetching node information!!\n";
    $nodeInfo = "perkele"; 
  }
  return $nodeInfo;
}

# modify these as needed
my $numOfNodes = 24;
my $queryPort = 8649; # port to query xml trees from nodes
my $serverPort = 8666; # port to serve gathered data
my $localip = "193.167.234.240";


my $serverSocket;
my $host;
my $tmp;
my $nodeInfo;
my @hosts;

# modify hostnames as needed
$hosts[0] = "klunga";
my $i = 1; 
for ($i = 1; $i < $numOfNodes; $i++) {
  $hosts[$i] = "node"."$i";
}

my $header; 

my $tailer = "</CLUSTER>\n</GANGLIA_XML>\n";

$serverSocket = new IO::Socket::INET (LocalHost => $localip,
				      LocalPort => $serverPort,
				      Proto     => 'tcp',
				      Listen    => 5,
				      Reuse     => 1
				     );
die "Socket could not be created. Reason: $!" unless $serverSocket;
my $new_sock;
while ($new_sock = $serverSocket->accept()) {
  $nodeInfo = ""; 
  foreach $host (@hosts) {
    $tmp = getNodeInfo($host, $queryPort); 
    $nodeInfo .= $tmp; 
  }
  $header = getHeader("klunga", $queryPort);
  $new_sock->send($header);
  $new_sock->send($nodeInfo);
  $new_sock->send($tailer);
  close $new_sock;
}
close ($serverSocket);