MySQL 8.0 Release Notes
MySQL 8.0 Source Code Documentation
[+/-]
- 5.4.2.1 Error Log Component Configuration
- 5.4.2.2 Default Error Log Destination Configuration
- 5.4.2.3 Types of Error Log Filtering
- 5.4.2.4 Priority-Based Error Log Filtering (log_filter_internal)
- 5.4.2.5 Rule-Based Error Log Filtering (log_filter_dragnet)
- 5.4.2.6 Error Logging in JSON Format
- 5.4.2.7 Error Logging to the System Log
- 5.4.2.8 Error Log Message Format
- 5.4.2.9 Error Log File Flushing and Renaming
This section discusses how to configure the MySQL server for logging of diagnostic messages to the error log. For information about selecting the error message character set or language, see Section 10.6, “Error Message Character Set”, or Section 10.11, “Setting the Error Message Language”.
The error log contains a record of mysqld startup and shutdown times. It also contains diagnostic messages such as errors, warnings, and notes that occur during server startup and shutdown, and while the server is running. For example, if mysqld notices that a table needs to be automatically checked or repaired, it writes a message to the error log.
On some operating systems, the error log contains a stack trace if mysqld exits abnormally. The trace can be used to determine where mysqld exited. See Section 29.5, “Debugging and Porting MySQL”.
If used to start mysqld,
mysqld_safe may write messages to the error
log. For example, when mysqld_safe notices
abnormal mysqld exits, it restarts
mysqld and writes a mysqld
restarted message to the error log.
The following sections discuss aspects of configuring error logging.