I have a WordPress install on a dedicated server with decent memory (upwards of 8GB).
The stack is LAMP - CentOS 6.3, Apache 2.4.4, Percona MySQL, PHP-FPM.
I have been quite stupid, and didn't set up a test or staging server.
Everything was running fine till I updated to WordPress 3.8, and also updated several plugins at the same time.
I didn't pay attention at the time, but all my widgets got messed up, and so did any sort of navigation etc.
I enabled error_log for a bit, i.e.
ini_set('log_errors',TRUE); ini_set('error_reporting', E_ALL); ini_set('error_log', dirname(__FILE__) . '/error_log.txt');
This resulted in an immense file - basically the error_log grows by about a GB every 4 minutes or so.
The primary error I found in the error log was database server disconnect, better known as
MySQL server has gone away
As suggested at Rackspace, I edited my.cnf to add
wait_timeout = 60
Also added caching to my.cnf
query_cache_type = 1 query_cache_limit = 8M query_cache_size = 512M
(and yes, I restarted mysql every time I edited my.cnf)
Also tried the method suggested here: In wp-db.php before
$this->select( $this->dbname, $this->dbh );
$this->query("set session wait_timeout=600" );
I'm at my wit's end. Please help!