Tiemout after 5 seconds

  // normal option you'd also expect when using e.g., Python's `requests` library.

  curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

  // If the FS server is down on a network level, curl will wait until timeout before responding with a failure.

  // We set the timeout to 5s (maybe lower would be better), to still give a fast (albeit negative) response

  // when the FS server is down.

  curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 5);

  // Append the handle to the array of handles (we need it later to get the response code) and add

  // it to the multi handle (which we need to make the requests in batch).

  $handles[] = $ch;