The Error Log 5.4.2.5 Priority-Based Error Log Filtering (log_filter_internal) Verbosity Filtering Suppression-List Filtering The  log_error_suppression_list  system variable applies to events intended for the error log and specifies which events to suppress when they occur with a priority of  WARNING  or  INFORMATION . For example, if a particular type of warning is considered undesirable “noise”  in the error log because it The  log_filter_internal  log filter component implements a simple form of log filtering based on error event priority and error code. To affect how  log_filter_internal  permits or suppresses error, warning, and information events intended for the error log, set the  log_error_verbosity  and log_error_suppression_list  system variables. log_filter_internal  is built in and enabled by default. If this filter is disabled, log_error_verbosity  and  log_error_suppression_list  have no effect, so filtering must be performed using another filter service instead where desired (for example, with individual filter rules when using  log_filter_dragnet ). For information about filter configuration, see Section 5.4.2.1, “Error Log Configuration” . •Verbosity Filtering •Suppression-List Filtering •Verbosity and Suppression-List Interaction Events intended for the error log have a priority of  ERROR ,  WARNING , or  INFORMATION . The log_error_verbosity  system variable controls verbosity based on which priorities to permit for messages written to the log, as shown in the following table. log_error_verbosity Value Permitted Message Priorities 1 ERROR 2 ERROR ,  WARNING 3 ERROR ,  WARNING ,  INFORMATION If  log_error_verbosity  is 2 or greater, the server logs messages about statements that are unsafe for statement-based logging. If the value is 3, the server logs aborted connections and access-denied errors for new connection attempts. See Section B.3.2.9, “Communication Errors and Aborted Connections” . If you use replication, a  log_error_verbosity  value of 2 or greater is recommended, to obtain more information about what is happening, such as messages about network failures and reconnections. If  log_error_verbosity  is 2 or greater on a replica, the replica prints messages to the error log to provide information about its status, such as the binary log and relay log coordinates where it starts its job, when it is switching to another relay log, when it reconnects after a disconnect, and so forth. There is also a message priority of  SYSTEM  that is not subject to verbosity filtering. System messages about non-error situations are printed to the error log regardless of the  log_error_verbosity  value. These messages include startup and shutdown messages, and some significant changes to settings. In the MySQL error log, system messages are labeled as “System” . Other log sinks might or might not follow the same convention, and in the resulting logs, system messages might be assigned the label used for the information priority level, such as “Note”  or “Information” . If you apply any additional filtering or redirection for logging based on the labeling of messages, system messages do not override your filter, but are handled by it in the same way as other messages. 1033