/**
* {@inheritdoc}
* @see \Scalr\System\Zmq\Cron\TaskInterface::addWorker()
*/
public function addWorker($address = null)
{
$op = [];
$config = $this->config();
$args = '--name=' . ($address ?: $this->name);
exec(Launcher::getStartWorkerCommand() . ' ' . $args . ' ' . ($config->log == '/dev/null' ? '>' : '>>') . ' ' . escapeshellcmd($config->log) . ' 2>&1 & echo $!', $op);
$this->getLogger()->debug("Adding %s worker PID:%d", $address ?: $this->name, intval($op[0]));
return intval($op[0]);
}