The MySQL server, mysqld, has many command options and system variables that can be set at startup to configure its operation. MySQL服务器mysqld有许多命令选项和系统变量，可以在启动时设置这些选项和变量来配置其操作。To determine the default command option and system variable values used by the server, execute this command:要确定服务器使用的默认命令选项和系统变量值，请执行以下命令：

shell> mysqld --verbose --help

The command produces a list of all mysqld options and configurable system variables. 该命令生成所有mysqld选项和可配置系统变量的列表。Its output includes the default option and variable values and looks something like this:其输出包括默认选项和变量值，如下所示：

abort-slave-event-count           0
allow-suspicious-udfs             FALSE
archive                           ON
auto-increment-increment          1
auto-increment-offset             1
autocommit                        TRUE
automatic-sp-privileges           TRUE
avoid-temporal-upgrade            FALSE
back-log                          80
basedir                           /home/jon/bin/mysql-8.0/
...
tmpdir                            /tmp
transaction-alloc-block-size      8192
transaction-isolation             REPEATABLE-READ
transaction-prealloc-size         4096
transaction-read-only             FALSE
transaction-write-set-extraction  XXHASH64
updatable-views-with-limit        YES
validate-user-plugins             TRUE
verbose                           TRUE
wait-timeout                      28800

To see the current system variable values actually used by the server as it runs, connect to it and execute this statement:要查看服务器运行时实际使用的当前系统变量值，请连接到服务器并执行以下语句：

mysql> SHOW VARIABLES;

To see some statistical and status indicators for a running server, execute this statement:要查看正在运行的服务器的一些统计和状态指示器，请执行以下语句：

mysql> SHOW STATUS;

System variable and status information also is available using the mysqladmin command:使用mysqladmin命令还可以获得系统变量和状态信息：

shell> mysqladmin variables
shell> mysqladmin extended-status

For a full description of all command options, system variables, and status variables, see these sections:有关所有命令选项、系统变量和状态变量的完整说明，请参见以下部分：

More detailed monitoring information is available from the Performance Schema; see Chapter 27, MySQL Performance Schema. 更详细的监控信息可从性能模式获得；参见第27章，“MySQL性能模式”。In addition, the MySQL sys schema is a set of objects that provides convenient access to data collected by the Performance Schema; see Chapter 28, MySQL sys Schema.此外，MySQL sys架构是一组对象，提供了对性能模式收集的数据的方便访问；参见第28章，MySQL sys 架构。

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. 如果在命令行中为mysqld或mysqld_safe指定一个选项，则该选项仅对服务器的该调用有效。To use the option every time the server runs, put it in an option file. 要在每次服务器运行时使用该选项，请将其放入选项文件中。See Section 4.2.2.2, “Using Option Files”.参见第4.2.2.2节，“使用选项文件”。