This rule can actually be omitted because there are no prio  values greater than INFORMATION , so effectively it drops nothing. 

• err_code 

The numeric event error code. In comparisons, the value to test can be specified as a symbolic error name or an integer literal. Error symbols are recognized only in comparisons with the err_code  field and user-defined fields. These comparisons are equivalent: 

IF err_code == ER_ACCESS_DENIED_ERROR THEN ... IF err_code == 1045 THEN ... 

• err_symbol 

The event error symbol, as a string (for example, ’ER_DUP_KEY’ ). err_symbol  values are intended more for identifying particular lines in log output than for use in filter rule comparisons because log_filter_dragnet  does not resolve comparison values specified as strings to the equivalent numeric error code. (For that to occur, an error must be specified using its unquoted symbol.) 

## Optional Field References 

The log_filter_dragnet  grammar at Grammar for log_filter_dragnet Rule Language names the optional fields that filter rules recognize. For general descriptions of these fields, see Section 5.4.2.3, “Error Event Fields” , with which you are assumed to be familiar. The following remarks provide additional information only as it pertains specifically to optional field references as used within log_filter_dragnet  rules. 

• label 

The label corresponding to the prio  value, as a string. Filter rules can change the label for log sinks that support custom labels. label  values are intended more for identifying particular lines in log output than for use in filter rule comparisons because log_filter_dragnet  does not resolve comparison values specified as strings to the equivalent numeric priority. 

• source_file 

The source file in which the event occurred, without any leading path. For example, to test for the sql/ gis/distance.cc  file, write the comparison like this: 

## User-Defined Field References 

IF source_file == "distance.cc" THEN ... 

Any field name in a log_filter_dragnet  filter rule not recognized as a core or optional field name is taken to refer to a user-defined field. 

## 5.4.2.7 Error Logging in JSON Format 

This section describes how to configure error logging using the built-in filter, log_filter_internal , and the JSON sink, log_sink_json , to take effect immediately and for subsequent server startups. For general information about configuring error logging, see Section 5.4.2.1, “Error Log Configuration” . 

To enable the JSON sink, first load the sink component, then modify the log_error_services  value: 

INSTALL COMPONENT ’file://component_log_sink_json’; SET PERSIST log_error_services = ’log_filter_internal; log_sink_json’; 

