As per the MySQL documentation:
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.
The error log subsystem consists of components that perform log event filtering and writing, as well as a system variable called log_error_services
that configures which components to enable to achieve the desired logging result. The default value of global.log_error_services
is log_filter_internal; log_sink_internal
:
mysql> SELECT @@global.log_error_services; +----------------------------------------+ | @@global.log_error_services | +----------------------------------------+ | log_filter_internal; log_sink_internal | +----------------------------------------+
That value indicates that log events first pass through the built-in filter component, log_filter_internal
, then through the built-in log writer component...