WordPress and PHP tend to hide a very important problem, that can get on your nerves.
Complains typically sound like this:
- My WordPress is stuck, When I log in I see only blank screen, I can’t do anything!
And it can be very tricky, because for some type of users WordPress can show admin panel, but for others, just a blank screen.
Then you ask developer to check errors, he examines the web server (e.g. apache) error log and does not find any fatal error, that could cause the blank screen of death for WordPress.
So the problem PHP and WordPress hide, is insufficient memory dedicated to a single script. This is the directive in php.ini that is responsible for memory allocated for each script “memory_limit”. Look for it in php.ini and increase it to solve the memory issue.
memory_limit = 128M
Increase of memory consumption by WordPress is mostly related to plugins that used to keep their data in the wp_options table. Because whatever plug-ins keep in that table, WordPress automatically loads to memory upon each run.
One example of this is Nextend Facebook connect plugin, that enables visitors to log-in via Facebook account. Be aware that for each user it keeps 4 recored in the wp_options table, and if you have 10.000 users, speed of your WordPress will degrade significantly.
To solve this issue, just run this command with cron job every hour
$wpdb->query(“DELETE FROM `wp_options` WHERE `option_name` LIKE (‘%_transient_%’)”);