29.12.21.1 The setup_loggers Table

The setup_loggers table lists the registered loggers and their logging level:

mysql>  select * from performance_schema.setup_loggers;
+------------------------+-------+-------------------------+
| NAME                   | LEVEL | DESCRIPTION             |
+------------------------+-------+-------------------------+
| logger/sql/error_log   | info  | MySQL error logger      |
| logger/sql/slow_log    | info  | MySQL slow query logger |
| logger/sql/general_log | info  | MySQL general logger    |
+------------------------+-------+-------------------------+

• NAME: The name of the logger.

  This can be one of the following:

  • logger/sql/error_log

  • logger/sql/general_log

    The General log does not have a log level. All logs are instrumented using INFO. It is also independent of the existing configuration. For example, if log_output or general_log is disabled, general OpenTelemetry logging continues.

  • logger/sql/slow_log

    The Slow Query log does not have a log level. All logs are instrumented using WARN. It is also independent of the existing configuration. For example, if log_output or slow_query_log is disabled, Slow Query OpenTelemetry logging continues. Similarly, on replicas, if log_slow_replica_statements is disabled, Slow query OpenTelemetry logging continues on the replica.

• LEVEL: The log level. This can be set to one of the following values:

  • none

  • error

  • warn

  • info

  • debug

• DESCRIPTION: A text description of the logger.

Server Configuration Command Line

This section describes the logger-related command line configuration options.

• performance-schema-logger: defines the default values for loggers. This can be defined multiple times, similarly to --performance-schema-instrument.

  In the following example, all loggers are configured with the error level ERROR, except foo and bar which are configured to error level INFO and WARNING, respectively:

                --performance-schema-logger = 'logger/% = Level:ERROR' --performance-schema-logger = 'logger/foo/% = Level:INFO' 
                --performance-schema-logger = 'logger/bar/% = Level:WARNING'

  To see the configured loggers, run the following:

  select * from performance_schema.setup_loggers;
  +------------------------+-------+-------------------------+
  | NAME                   | LEVEL | DESCRIPTION             |
  +------------------------+-------+-------------------------+
  | logger/sql/error_log   | info  | MySQL error logger      |
  | logger/sql/slow_log    | info  | MySQL slow query logger |
  | logger/sql/general_log | info  | MySQL general logger    |
  +------------------------+-------+-------------------------+

  This example shows the default MySQL error logger. This can be set to one of the following values:

  • none

  • error

  • warn

  • info

  • debug

  The following example changes the error logging level to WARNING:

  mysql> UPDATE performance_schema.setup_loggers
         SET LEVEL='WARN'

• performance_schema_max_logger_classes: this system variable can also be set from the command line. For example:

                --performance_schema_max_logger_classes=100

  Editing this value requires a server restart.