Where is the mysql log file?

This article will introduce several log file locations in mysql and how to find them.

Recommended course: MySQL tutorial

Mysql log file query method:

Find the error log file path

show variables like ‘log_error’;

In the mysql database, the error log function is enabled by default. Also, error logging cannot be disabled. By default, error logs are stored in the data files of the mysql database. The error log file is usually named hostname.err. Among them, hostname represents the server host name.

The error log information can be configured by yourself. The information recorded in the error log can be defined through log-error and log-warnings, where log-err is the function and error log that defines whether to enable the error log. The storage location, log-warnings defines whether warning information is also defined in the error log.

By default, the error log probably records the following aspects of information: information during server startup and shutdown (not necessarily error information, such as how mysql starts the InnoDB table space file, how to initialize its own storage engine, etc.), error messages while the server is running, messages generated when the event scheduler runs an event, messages generated when starting a server process from the server.

Find the log file path

show variables like ‘general_log_file’;

The log is an important part of the mysql database. The log file records changes that occur during the operation of the mysql database; that is, it is used to record the client connection status of the mysql database, the execution of SQL statements, and error messages. When the database is accidentally damaged, the cause of the file error can be viewed through the log, and data recovery can be performed through the log file.

Slow query log file path

show variables like ‘slow_query_log_file’;

The slow query log is used to record query statements whose execution time exceeds the specified time. Through the slow query log, you can find out which query statements have low execution efficiency for optimization. It is generally recommended to turn it on. It has minimal impact on server performance, but it can record query statements that have been executed on the mysql server for a long time. Can help us locate performance issues.

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