MySQLTuning

mysqltuner

Run mysqltuner to get some initial recommendations:

# Install mysqltuner if you haven't already
sudo apt-get install mysqltuner

# Run mysqltuner
sudo mysqltuner

/etc/mysql/my.cnf vs /etc/mysql/conf.d/

Implement mysqltuner's recommendations in /etc/mysql/my.cnf or create a new file in /etc/mysql/conf.d/ with the changes. We recommend /etc/mysql/conf.d/ so that your changes don't get overwritten during MySQL package upgrades.

Restart MySQL

Changes don't take effect until MySQL is restarted and you should ensure that Sguil and other services aren't using MySQL before shutting it down.

Variables

The first variable that you'll probably need to tune is open-files-limit: error_code_24 out-of-resources

Here are some other common variables that will probably need to be tuned for your system:

• table_cache
• key_buffer
• max_connections

MySQL slow to start on boot

At boot time, MySQL checks all tables, which can take a long time. If you wish to disable this check, comment out check_for_crashed_tables in /etc/mysql/debian-start.