Shaun Haber

We have over 100 sites setup in a multi-site shared code-base environment. Cron runs every 10 minutes on every site. In order to prevent saturating our bandwidth with frequent cron calls, we setup a command-line php script that bootstraps Drupal and invokes cron. This has very little overhead since it bypasses HTTP.

You can place the file in the drupal root, then run it by calling:
> php cron-cli.php mysite.com

Here’s what the code looks like:

<?php
if (!$_SERVER['argc']) {
  die("No arguments.");
}

$_SERVER['HTTP_HOST'] = $_SERVER['argv'][1];
$_SERVER['SCRIPT_NAME'] = '/'.$_SERVER['SCRIPT_NAME'];

ini_set('memory_limit', '256M');
ini_set('max_execution_time', 300); // Needed for feedapi to work!

include_once './includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);

$semaphore = variable_get('cron_semaphore', FALSE);
if ($semaphore) {
  if (time() - $semaphore > 1200) {
      // Either cron has been running for more than 20 min or the semaphore
      // was not reset due to a database error.

      // Release cron semaphore
      variable_del('cron_semaphore');
    }
  else {
    die("Attempting to re-run cron while it is already running. $semaphore\n");
  }
}

// Lock cron semaphore
variable_set('cron_semaphore', time());

echo $_SERVER['HTTP_HOST']."\n";

$modules = module_implements('cron');

foreach($modules as $module) {
  echo "Invoking cron for $module... ";
  module_invoke($module,'cron');
  $time = time();
  echo $time."\n";
  flush();
}

variable_set('cron_last', $time);
echo "\n";

// Release cron semaphore
variable_del('cron_semaphore');