MySQL :: MySQL 8.0 Reference Manual :: 5.1.1 Configuring the Server

5.1.1 Configuring the Server

The MySQL server, mysqld, has many command options and system variables that can be set at startup to configure its operation. To determine the default command option and system variable values used by the server, execute this command:

shell> mysqld --verbose --help

The command produces a list of all mysqld options and configurable system variables. Its output includes the default option and variable values and looks something like this:

abort-slave-event-count           0allow-suspicious-udfs             FALSEarchive                           ONauto-increment-increment          1auto-increment-offset             1autocommit                        TRUEautomatic-sp-privileges           TRUEavoid-temporal-upgrade            FALSEback-log                          80basedir                           /home/jon/bin/mysql-8.0/...tmpdir                            /tmptransaction-alloc-block-size      8192transaction-isolation             REPEATABLE-READtransaction-prealloc-size         4096transaction-read-only             FALSEtransaction-write-set-extraction  OFFupdatable-views-with-limit        YESvalidate-user-plugins             TRUEverbose                           TRUEwait-timeout                      28800

To see the current system variable values actually used by the server as it runs, connect to it and execute this statement:

mysql> SHOW VARIABLES;

To see some statistical and status indicators for a running server, execute this statement:

mysql> SHOW STATUS;

System variable and status information also is available using the mysqladmin command:

shell> mysqladmin variablesshell> mysqladmin extended-status

For a full description of all command options, system variables, and status variables, see these sections:

• Section 5.1.7, “Server Command Options”

• Section 5.1.8, “Server System Variables”

• Section 5.1.10, “Server Status Variables”

More detailed monitoring information is available from the Performance Schema; see Chapter 26, MySQL Performance Schema. In addition, the MySQL sys schema is a set of objects that provides convenient access to data collected by the Performance Schema; see Chapter 27, MySQL sys Schema.

If you specify an option on the command line for mysqld or mysqld_safe, it remains in effect only for that invocation of the server. To use the option every time the server runs, put it in an option file. See Section 4.2.2.2, “Using Option Files”.