The HTTP Parallel Request & Threading Library (HTTPRL) module may require some special configuration to use on Cloud Platform. The default HTTPRL configuration assumes that SSL requests are handled by the web infrastructure; on Cloud Platform, SSL requests are handled by the load balancer or Elastic Load Balancer. As a result, you may see an error like this:

Error
 HTTPRL - Core   drupal_http_request()
 Your system or network configuration does not allow Drupal to access web
 pages. This could be due to your webserver configuration or PHP settings.

This error does not interfere with the normal operation of your Drupal application on Cloud Platform, but it is a good idea to configure your application so that it doesn’t generate errors that don’t actually indicate that a problem exists.

To eliminate this error message, set the httprl_server_addr variable to -1, so that the HTTPRL module uses the host name instead of an IP address for self-infrastructure requests. To do this, use one of the following methods:

• Add the following line to your settings.php file:

  $conf['httprl_server_addr'] = -1;
  // If set to -1 httprl will use the host name
  // instead of an IP address for self-server requests.
  

• Set the following variable using Drush:

  drush ev 'variable_set("httprl_server_addr", -1);'