Error establishing a database connection to Cloud SQL

Question

please forgive a novice question:

I have Wordpress up and running on my development server with no problems. When I try to upload it using appengine, I get the following error output from WP_DEBUG, where MYSITEID is the name of my site:

Warning: mysqli_connect(): (HY000/2002): Unable to find the socket transport "tcp" -
did you forget to enable it when you configured PHP? in 
/base/data/home/apps/s~MYSITEID/wp.370505361471441320/wordpress/wp-content/db.php on line 176

It goes on:

"This either means that the username and password information in your wp-config.php file is incorrect or we can't contact the database server at :/cloudsql/MYSITEID:wordpress . This could mean your host's database server is down."

My Cloud SQL instance is up and running and I followed the tutorial steps 7 and 8 exactly.

My wp_config db_host section reads:

/** MySQL hostname */
if(isset($_SERVER['SERVER_SOFTWARE']) && strpos($_SERVER['SERVER_SOFTWARE'],'Google App Engine') !== false) {
  define('DB_HOST', ':/cloudsql/MYSITEID:wordpress');
}else{
  define('DB_HOST', 'localhost');
}

From the looks of it my error text is almost verbatim what a phpmyadmin user encountered, but I'm still not sure how to resolve it. Do I need to change something on the DB_HOST line? See phpMyAdmin on GAE - Authentication

Thanks for any help - really appreciate that GAE for PHP exists!

Answer 1

Turns out the issue was in db.php - which I had installed in wp-content per the instructions here: http://wordpress.org/plugins/mysqli/installation/

I'm not sure why I originally installed mysqli instead of using mysql; it seemed to fix an earlier php error I was having on my development server. But after removing db.php both my dev version and the Cloud SQL instance work just fine!