Mysql notes

Notes on MySQL:

I generally store my MySQL password in an environment variable (like MYSQL_PASSWORD) and then have all of the mysql commands aliased to use the password, e.g.:

 alias mysql="mysql -p$MYSQL_PASSWORD"
 alias mysqladmin="mysqladmin -p$MYSQL_PASSWORD"

Tuning MySQL

Look at the system load. If mysqld is not consuming 100% of the system load, then it is disk-bound, not CPU bound. You need to increase the buffers.

In the file my.cnf, try editing these values and making them larger until the system is CPU bound:

 key_buffer              = 8192M
 innodb_buffer_pool_size = 1024M
 sort_buffer_size = 100M
 read_buffer_size = 100M
 read_rnd_buffer_size = 100M
 myisam_sort_buffer_size = 100M
 query_cache_size = 1024M

 # Try number of CPU's*2 for thread_concurrency
 thread_concurrency = 8

Try these commands:

 mysql> SHOW INNODB STATUS\G

See also:

• http://www.mysqlperformanceblog.com/2007/11/01/innodb-performance-optimization-basics/
• http://www.mysqlperformanceblog.com/

General

Useful admin commands

 mysqladmin shutdown

MacOS Server

MySQL is built in. I find it easier to use Apple's provided server, rather than building my own:

To restart the server (for some reason, launchctl doesn't stop the MySQL server):

 mysqladmin shutdown
 sudo launchctl start org.mysql.mysqld

Linux

Restart MySQL:

 sudo /etc/init.d/mysql restart