Upgrade Openssl Fixes Heartbleed but results in Magento MySQL Error

Question

After updating and upgrading the heartbleed bug on our Ubuntu 12.04 server, I've encountered a MySQL error displaying on our Magento hosted sites' landing pages only:

SQLSTATE[HY000]: General error: 23 Out of resources when opening file '/tmp/#sql_360_0.MYD' (Errcode: 24)

Before we started, we backed up everything. Then I executed the following commands:

sudo apt-get clean
sudo apt-get update
sudo apt-get install openssl libssl1.0.0
reboot

According to https://filippo.io/Heartbleed/, the openssl was successfully patched. Now all Magento 1.8 sites are broken with the same error (above) but the Joomla sites seem to be unaffected. All sites are using MySQL 5.5.35.

To see if it was a dependency version issue, I've also tried the following commands but it resulted in no change:

sudo apt-get upgrade
reboot

I've also cleared the Magento cache and session folders.

Answer 1

Based on some limited internet research, it sounds like

General error: 23 Out of resources when opening file

Is MySQL's way of saying

I need to open more files than the operating system will allow.

So, the OpenSLL update, or some other thing that happened since the last time you rebooted the server (or restarted MySQL?) restricted the number of files an application is allowed to open.

Based on some old blog posts, it sounds like you'll want to edit the number of allowed files in

/etc/security/limits.conf

Looking for the lines

and add:
mysql soft nofile ....
mysql hard nofile ....

Where .... is the current number of files you're allowed to have open. It also sounds like you may want to FLUSH TABLES on your MySQL server to clear out any old files MySQL is holding open for MyISAM's partition tables.