I inherited a mysql server, and so I've started with running the MySQLTuner.pl script. I am not a MySQL expert but I can see that there is definitely a mess here. I'm not looking to go after every single thing that needs fixing and tuning, but I do want to grab the major, low hanging fruit.
Total Memory on the system is: 512MB. Yes, I know it's low, but it's what we have for the time being.
Here's what the script had to say:
General recommendations: Run OPTIMIZE TABLE to defragment tables for better performance MySQL started within last 24 hours - recommendations may be inaccurate Enable the slow query log to troubleshoot bad queries When making adjustments, make tmp_table_size/max_heap_table_size equal Reduce your SELECT DISTINCT queries without LIMIT clauses Increase table_cache gradually to avoid file descriptor limits Your applications are not closing MySQL connections properly Variables to adjust: query_cache_limit (> 1M, or use smaller result sets) tmp_table_size (> 16M) max_heap_table_size (> 16M) table_cache (> 64) innodb_buffer_pool_size (>= 326M)
For the variables that it recommends that I adjust, I don't even see most of them in the mysql.cnf file.
[client] port = 3306 socket = /var/run/mysqld/mysqld.sock [mysqld_safe] socket = /var/run/mysqld/mysqld.sock nice = 0 [mysqld] innodb_buffer_pool_size = 220M innodb_flush_log_at_trx_commit = 2 innodb_file_per_table = 1 innodb_thread_concurrency = 32 skip-locking big-tables max_connections = 50 innodb_lock_wait_timeout = 600 slave_transaction_retries = 10 innodb_table_locks = 0 innodb_additional_mem_pool_size = 20M user = mysql socket = /var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp skip-external-locking bind-address = localhost key_buffer = 16M max_allowed_packet = 16M thread_stack = 192K thread_cache_size = 4 myisam-recover = BACKUP query_cache_limit = 1M query_cache_size = 16M log_error = /var/log/mysql/error.log expire_logs_days = 10 max_binlog_size = 100M skip-locking innodb_file_per_table = 1 big-tables [mysqldump] quick quote-names max_allowed_packet = 16M [mysql] [isamchk] key_buffer = 16M !includedir /etc/mysql/conf.d/