# === Optimized my.cnf configuration for MySQL/MariaSQL (on Ubuntu, CentOS etc. servers) === # # by Fotis Evangelou, developer of Engintron (engintron.com) # # ~ Updated February 2021 ~ # # # The settings provided below are a starting point for a 8-16 GB RAM server with 4-8 CPU cores. # If you have different resources available you should adjust accordingly to save CPU, RAM & disk I/O usage. # # The settings marked with a specific comment or the word "UPD" (after the value) # should be adjusted for your system by using database diagnostics tools like: # # https://github.com/major/MySQLTuner-perl # or # https://github.com/RootService/tuning-primer (supports MySQL up to v5.7) # # Run either of these scripts before optimizing your database, at least 1 hr after the optimization & finally # at least once a day for 3 days (without restarting the database) to see how your server performs and if you need # to re-adjust anything. The more MySQL/MariaDB runs without restarting, the more usage data it gathers, so these # diagnostics scripts will report in mode detail how MySQL/MariaDB performs. # # # IMPORTANT NOTE: If there is NO comment after a setting value, then 99,9% of the times you won't need to adjust it. # # # --- THINGS TO DO AFTER YOU UPDATE MY.CNF - TROUBLESHOOTING --- # # If any terminal commands are mentioned, make sure you execute them as "root" user. # # If MySQL or MariaDB cannot start (or restart), then perform the following actions. # # 1. If the server had the stock database configuration and you added or updated any # "innodb_log_*" settings (as suggested below), then execute these commands ONLY # the first time you apply this configuration: # # $ rm -rvf /var/lib/mysql/ib_logfile* # $ chown -R mysql:mysql /var/lib/mysql # $ service mysql restart # # or use the shorthand command: # $ rm -rvf /var/lib/mysql/ib_logfile*; chown -R mysql:mysql /var/lib/mysql; service mysql restart # # 2. If the setting "bind-address" is not commented out, then make sure the file /etc/hosts is # properly configured. A good example of a "clean" /etc/hosts file is something like this: # # 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 # ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 # 1.2.3.4 hostname.domain.tld hostname # <-- Replace accordingly! # # Finally restart the database service: # # $ service mysql restart # # 3. If the database service cannot restart even after the first 2 steps, make sure the database data folder # (common for either MySQL or MariaDB) "/var/lib/mysql" is owned by the "mysql" user AND group. # Additionally, the folder itself can have 0751 or 0755 file permissions. To fix it, simply do this: # $ chown -R mysql:mysql /var/lib/mysql # $ chmod 0755 /var/lib/mysql # # Finally restart the database service: # # $ service mysql restart # # # ~ FIN ~ [mysql] port = 3306 socket = /var/run/mysqld/mysqld.sock [mysqld] # === Required Settings === basedir = /usr bind_address = 127.0.0.1 # Change to 0.0.0.0 to allow remote connections datadir = /var/lib/mysql max_allowed_packet = 256M max_connect_errors = 1000000 pid_file = /var/run/mysqld/mysqld.pid port = 3306 skip_external_locking skip_name_resolve socket = /var/run/mysqld/mysqld.sock tmpdir = /tmp user = mysql # === SQL Compatibility Mode === # Enable for b/c with databases created in older MySQL/MariaDB versions # (e.g. when using null dates) #sql_mode = ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION,ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES # === InnoDB Settings === default_storage_engine = InnoDB innodb_buffer_pool_instances = 4 # Use 1 instance per 1GB of InnoDB pool size innodb_buffer_pool_size = 4G # Use up to 70-80% of RAM innodb_file_per_table = 1 innodb_flush_log_at_trx_commit = 0 innodb_flush_method = O_DIRECT innodb_log_buffer_size = 16M innodb_log_file_size = 1G innodb_stats_on_metadata = 0 #innodb_temp_data_file_path = ibtmp1:64M:autoextend:max:20G # Control the maximum size for the ibtmp1 file #innodb_thread_concurrency = 4 # Optional: Set to the number of CPUs on your system (minus 1 or 2) to better # contain CPU usage. E.g. if your system has 8 CPUs, try 6 or 7 and check # the overall load produced by MySQL/MariaDB. innodb_read_io_threads = 64 innodb_write_io_threads = 64 #innodb_io_capacity = 1000 # Max is 2000 # === MyISAM Settings === # The following 3 options are ONLY supported by MariaDB & up to MySQL 5.7 # Do NOT un-comment on MySQL 8.x+ #query_cache_limit = 4M # UPD #query_cache_size = 64M # UPD #query_cache_type = 1 # Enabled by default key_buffer_size = 32M # UPD low_priority_updates = 1 concurrent_insert = 2 # === Connection Settings === max_connections = 100 # UPD - Important: high no. of connections = high RAM consumption back_log = 512 thread_cache_size = 100 thread_stack = 192K interactive_timeout = 180 wait_timeout = 180 # For MySQL 5.7+ only (disabled by default) #max_execution_time = 30000 # Set a timeout limit for SELECT statements (value in milliseconds). # This option may be useful to address aggressive crawling on large sites, # but it can also cause issues (e.g. with backups). So use with extreme caution and test! # More info at: https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_max_execution_time # For MariaDB 10.1.1+ only (disabled by default) #max_statement_time = 30 # The equivalent of "max_execution_time" in MySQL 5.7+ (set above) # The variable is of type double, thus you can use subsecond timeout. # For example you can use value 0.01 for 10 milliseconds timeout. # More info at: https://mariadb.com/kb/en/aborting-statements/ # === Buffer Settings === innodb_sort_buffer_size = 2M # UPD join_buffer_size = 4M # UPD read_buffer_size = 3M # UPD read_rnd_buffer_size = 4M # UPD sort_buffer_size = 4M # UPD # === Table Settings === # In systemd managed systems like Ubuntu 16.04+ or CentOS 7+, you need to perform an extra action for table_open_cache & open_files_limit # to be overriden (also see comment next to open_files_limit). # E.g. for MySQL 5.7, please check: https://dev.mysql.com/doc/refman/5.7/en/using-systemd.html # and for MariaDB check: https://mariadb.com/kb/en/library/systemd/ table_definition_cache = 40000 # UPD table_open_cache = 40000 # UPD open_files_limit = 60000 # UPD - This can be 2x to 3x the table_open_cache value or match the system's # open files limit usually set in /etc/sysctl.conf or /etc/security/limits.conf # In systemd managed systems this limit must also be set in: # /etc/systemd/system/mysqld.service.d/override.conf (for MySQL 5.7+) and # /etc/systemd/system/mariadb.service.d/override.conf (for MariaDB) max_heap_table_size = 128M tmp_table_size = 128M # === Search Settings === ft_min_word_len = 3 # Minimum length of words to be indexed for search results # === Logging === log_error = /var/lib/mysql/mysql_error.log log_queries_not_using_indexes = 1 long_query_time = 5 slow_query_log = 0 # Disabled for production slow_query_log_file = /var/lib/mysql/mysql_slow.log [mysqldump] # Variable reference # For MySQL 5.7+: https://dev.mysql.com/doc/refman/5.7/en/mysqldump.html # For MariaDB: https://mariadb.com/kb/en/library/mysqldump/ quick quote_names max_allowed_packet = 512M