source: scripts/online.php

<?php

// Script executed by cron every 5 minutes

include('../includes/config.php');

$Database = new mysqli($db_config['host'], $db_config['user'], $db_config['pass'], $db_config['name']);

if(mysqli_connect_errno()) 
{
  printf("Connect failed: %s\n", mysqli_connect_error());
  exit();
}

function CheckPortStatus($Ip, $Port)
{
  $Timeout = 1;
  if($Socket = @fsockopen($Ip, $Port, $ErrorNumber, $ErrorString, $Timeout))
  {
    fclose($Socket);
    return(1);
  } else
  {
    return(0);
  }
}

$TextState = array('Offline', 'Online');

echo("Kontroluji stav serveru...<br>\n");
$PlayersCount = 0;
$OnlineCount = 0;
$OfflineCount = 0;
$Servers = $Database->query("SELECT `id`,`ip`,`port`,`name` FROM `servers`");
while($Server = $Servers->fetch_array())
{
  echo($Server['name'].' - ');
  $MeasureStart = microtime(TRUE);
  $OnlineState = CheckPortStatus($Server['ip'], $Server['port']);
  $Latency = (microtime(TRUE) - $MeasureStart) * 1000;
  $OnlineCount += $OnlineState;
  $OfflineCount += 1 - $OnlineState;
  // Insert new online state
  $Database->query("INSERT INTO `servers_online` (`server`, `time`, `state`, `players_count`, `latency`) VALUES (".$Server['id'].", NOW() , ".$OnlineState.", ".$PlayersCount.", ".$Latency.")");

  // Delete old records
  $Database->query("DELETE FROM `servers_online` WHERE `server` = ".$Server['id']." AND time < DATE_SUB(NOW(), INTERVAL ".$Config['OnlineStatePeriodLength']." DAY)");
 
  // Calculate latency average 
  $DbResult = $Database->query("SELECT COALESCE(AVG(`latency`), 0) as `latency` FROM `servers_online` WHERE `server` = ".$Server['id']." AND `state` = 1 AND `latency` != 0");
  $DbRow = $DbResult->fetch_array();
  $Latency = $DbRow['latency'];
  $DbResult->free();

  // Calculate cached percentage online state
  $DbResult = $Database->query("SELECT COALESCE(COUNT(*), 1) as `count`, COALESCE(SUM(`state`), 0) as `online` FROM `servers_online` WHERE `server` = ".$Server['id']);
  $DbRow = $DbResult->fetch_array();

  // Update servers info
  $Database->query("UPDATE `servers` SET `online` = ".round($DbRow['online'] / $DbRow['count'] * 100, 2).", `latency` = ".$Latency." WHERE `id` = ".$Server['id']);
  $DbResult->free();
  echo($TextState[$OnlineState]."<br>\n");
  flush();
}
$Servers->free();

echo('Total: '.($OnlineCount + $OfflineCount).', Online: '.$OnlineCount.', Offline: '.$OfflineCount."<br>\n");

?>