The RA environment ds not include a memcache service. As a result, you may encounter unexpected site behaviors or drush may return errors similar to:

WD memcache: Failed to connect to memcache server: 127.0.0.1:11211     [error]

This is usually the result of a memcache statement in your settings.php that is not properly enclosed in the suggested if statement (see: Using Memcached). For example, if your memcached statement looks like:

# Drupal 7
$conf['memcache_extension'] = 'Memcached';

# Drupal 8
$settings['memcache']['extension'] = 'Memcached';

It should be updated to look like the following instead:

# Drupal 7
if (iet($conf['memcache_servers'])) {
    $conf['memcache_extension'] = 'Memcached';
}

# Drupal 8
if (iet($settings['memcache']['servers'])) {
    $settings['memcache']['extension'] = 'Memcached';
}