当启用 InnoDB 监控器以进行定期输出时，InnoDB 会将输出写入 mysqld 服务器标准错误输出（stderr），大约每 15 秒一次。When InnoDB monitors are enabled for periodic output, InnoDB writes the output to mysqld server standard error output (stderr) every 15 seconds, approximately.

InnoDB 将监控器输出发送到 stderr，而不是 stdout 或固定大小的内存缓冲区，以避免潜在的缓冲区溢出。InnoDB sends the monitor output to stderr rather than to stdout or fixed-size memory buffers to avoid potential buffer overflows.

在 Windows 上，stderr 会被定向到默认日志文件，除非另行配置。如果您想将输出定向到控制台窗口，而不是错误日志，请在控制台窗口的命令提示符下使用 --console 选项启动服务器。有关更多信息，请参见 Windows 上的默认错误日志目标。On Windows, stderr is directed to the default log file unless configured otherwise. If you want to direct the output to the console window rather than to the error log, start the server from a command prompt in a console window with the --console option. For more information, see Default Error Log Destination on Windows.

在 Unix 及类 Unix 系统中，stderr 通常会被定向到终端，除非另行配置。更多信息，请参见 Unix 和类 Unix 系统的默认错误日志目的地。On Unix and Unix-like systems, stderr is typically directed to the terminal unless configured otherwise. For more information, see Default Error Log Destination on Unix and Unix-Like Systems.

只有在你确实想查看监控信息时才应启用 InnoDB 监控器，因为生成输出会导致一些性能下降。此外，如果监控器输出被定向到错误日志，如果之后忘记禁用监控器，日志可能会变得非常大。InnoDB monitors should only be enabled when you actually want to see monitor information because output generation causes some performance decrement. Also, if monitor output is directed to the error log, the log may become quite large if you forget to disable the monitor later.

InnoDB 监控输出以包含时间戳和监控名称的标题开始。例如：InnoDB monitor output begins with a header containing a timestamp and the monitor name. For example:

=====================================
2014-10-16 18:37:29 0x7fc2a95c1700 INNODB MONITOR OUTPUT
=====================================

标准 InnoDB 监控器（INNODB MONITOR OUTPUT）的标题也用于锁监控器，因为后者产生相同的输出，并附加额外的锁信息。The header for the standard InnoDB Monitor (INNODB MONITOR OUTPUT) is also used for the Lock Monitor because the latter produces the same output with the addition of extra lock information.

innodb_status_output 和 innodb_status_output_locks 系统变量用于启用标准的 InnoDB 监控器和 InnoDB 锁监控器。The innodb_status_output and innodb_status_output_locks system variables are used to enable the standard InnoDB Monitor and InnoDB Lock Monitor.

启用或禁用 InnoDB 监控器需要 PROCESS 权限。The PROCESS privilege is required to enable or disable InnoDB Monitors.

启用标准 InnoDB 监控器Enabling the Standard InnoDB Monitor

通过将 innodb_status_output 系统变量设置为 ON 来启用标准 InnoDB 监控器。Enable the standard InnoDB Monitor by setting the innodb_status_output system variable to ON.

SET GLOBAL innodb_status_output=ON;

要禁用标准的 InnoDB 监控器，请将 innodb_status_output 设置为 OFF。To disable the standard InnoDB Monitor, set innodb_status_output to OFF.

当您关闭服务器时，innodb_status_output 变量会被设置为默认的 OFF 值。When you shut down the server, the innodb_status_output variable is set to the default OFF value.

启用 InnoDB 锁监控器Enabling the InnoDB Lock Monitor

InnoDB 锁监控器的数据随 InnoDB 标准监控器的输出一起打印。必须同时启用 InnoDB 标准监控器和 InnoDB 锁监控器，才能定期打印 InnoDB 锁监控器的数据。InnoDB Lock Monitor data is printed with the InnoDB Standard Monitor output. Both the InnoDB Standard Monitor and InnoDB Lock Monitor must be enabled to have InnoDB Lock Monitor data printed periodically.

要启用 InnoDB 锁监视器，请将 innodb_status_output_locks 系统变量设置为 ON。必须同时启用 InnoDB 标准监视器和 InnoDB 锁监视器，才能定期打印 InnoDB 锁监视器数据：To enable the InnoDB Lock Monitor, set the innodb_status_output_locks system variable to ON. Both the InnoDB standard Monitor and InnoDB Lock Monitor must be enabled to have InnoDB Lock Monitor data printed periodically:

SET GLOBAL innodb_status_output=ON;
SET GLOBAL innodb_status_output_locks=ON;

要禁用 InnoDB 锁监控器，请将 innodb_status_output_locks 设置为 OFF。若要同时禁用 InnoDB 标准监控器，请将 innodb_status_output 设置为 OFF。To disable the InnoDB Lock Monitor, set innodb_status_output_locks to OFF. Set innodb_status_output to OFF to also disable the InnoDB Standard Monitor.

当您关闭服务器时，innodb_status_output 和 innodb_status_output_locks 变量将被设置为默认的 OFF 值。When you shut down the server, the innodb_status_output and innodb_status_output_locks variables are set to the default OFF value.

按需获取标准 InnoDB 监视器输出Obtaining Standard InnoDB Monitor Output On Demand

作为启用标准 InnoDB 监视器以定期输出的替代方法，您可以使用 InnoDB SQL 语句按需获取标准 SHOW ENGINE INNODB STATUS 监视器输出，该语句会将输出提取到您的客户端程序。如果您使用 mysql 交互式客户端，当您将通常的分号语句结束符替换为 \G 时，输出会更易读：As an alternative to enabling the standard InnoDB Monitor for periodic output, you can obtain standard InnoDB Monitor output on demand using the SHOW ENGINE INNODB STATUS SQL statement, which fetches the output to your client program. If you are using the mysql interactive client, the output is more readable if you replace the usual semicolon statement terminator with \G:

mysql> SHOW ENGINE INNODB STATUS\G

SHOW ENGINE INNODB STATUS 的输出还包括 InnoDB 锁监视器数据，如果 InnoDB 锁监视器已启用。SHOW ENGINE INNODB STATUS output also includes InnoDB Lock Monitor data if the InnoDB Lock Monitor is enabled.

将标准 InnoDB 监视器输出重定向到状态文件Directing Standard InnoDB Monitor Output to a Status File

通过在启动时指定 --innodb-status-file 选项，可以启用标准 InnoDB 监视器输出并将其重定向到状态文件。当使用此选项时，InnoDB 会在数据目录中创建一个名为 innodb_status.pid 的文件，并大约每 15 秒将输出写入该文件。Standard InnoDB Monitor output can be enabled and directed to a status file by specifying the --innodb-status-file option at startup. When this option is used, InnoDB creates a file named innodb_status.pid in the data directory and writes output to it every 15 seconds, approximately.

InnoDB 在服务器正常关闭时会移除状态文件。如果发生异常关闭，可能需要手动移除状态文件。InnoDB removes the status file when the server is shut down normally. If an abnormal shutdown occurs, the status file may have to be removed manually.

--innodb-status-file 选项用于临时使用，因为生成输出可能影响性能，而且 innodb_status.pid 文件随着时间可能会变得相当大。The --innodb-status-file option is intended for temporary use, as output generation can affect performance, and the innodb_status.pid file can become quite large over time.