Alternate page for mysql connection error

Question

I have a drupal 7 site. Recently I changed my mysql password but forgot to update the settings.php file. My website showed Cannot connect to mysql server for 3 days before I noticed and changed the settings.php file. My question is

Is there a way to display a custom HTML page (Like a maintenance page) when there is a mysql connection error ? Is there a module for that purpose ?

Answer 1

Having a look in drupal_bootstrap() for D7 it looks like hook_boot comes after the database "phase" so you'd need to put something in the cache phase or the configuration phase if you want to trigger a redirect before Drupal tries to bootstrap the database.

Easiest way would probably be to attempt to open a connection to the database yourself near the bottom of settings.php with the connection string defined earlier in settings.php and then if you detect a fail adapt this approach for "fast 404 pages" - http://2bits.com/drupal-planet/reducing-server-resource-utilization-busy-sites-implementing-fast-404s-drupal.html

You could print some html straight to the screen and exit().

Answer 2

As per David Meister's answer I've posted the code below for those who are new to Drupal. Copy and paste it at the bottom of the settings.php file. I know this is not a very elegant code but it gets the job done. If you have a better code please post your answer below.

$mysqli = new mysqli($databases['default']['default']['host'],$databases['default']['default']['username'],$databases['default']['default']['password'],$databases['default']['default']['database']);

    if (mysqli_connect_error()) {
     echo "Your HTML here";
     exit();
    }

Answer 3

I have added this code in settings.php and working fine.

try {
  require_once DRUPAL_ROOT . '/includes/database/database.inc';
  Database::getConnection();
}
  catch (Exception $e) {
  header("Location: $base_url/YOUR_HTML_PAGE.html");
  die;
}