public function onShutdown(swoole_server $server)
    {
        if (file_exists($this->pidFile)) {
            unlink($this->pidFile);
        }

        $this->console(sprintf('Server <info>%s</info> Master[<info>%s</info>] is shutdown ', $this->name, $server->master_pid), OutputInterface::VERBOSITY_DEBUG);
    }