How to disable/turn-off drupal 7 caching permanently, to not to mess with module's operations?
As per Suppress caching (for development), you can add the following to your settings.php file

if (!class_exists('DrupalFakeCache')) {
  $conf['cache_backends'][] = 'includes/cache-install.inc';
}
// Default to throwing away cache data
$conf['cache_default_class'] = 'DrupalFakeCache';
// Rely on the DB cache for form caching - otherwise forms fail.
$conf['cache_class_cache_form'] = 'DrupalDatabaseCache';


I'd recommend you don't just blindly add that, though. Instead, take the time to think what you do need to cache, and what you don't need to cache, and come up with a proper strategy. For example, it's hardly likely that you need rebuild the cache of hook implementations on every single page load, regardless of how highly available the site is.