Message Filtering

In addition to filtering log events based on thresholds that are assigned to loggers or appender definitions, the logging facility enables you to use filter classes to filter log events based on the following:
  • a character string in the message
  • a single threshold
  • a range of thresholds
  • a combination of strings and thresholds
Here is a list of the filter classes:
Filter Class Name
filters repeated log messages
filters messages based on a character string in the message.
filters messages based on a range of thresholds.
filters messages based on a single threshold.
filters messages based on the results of a list of other filters.
denies log events that did not meet the criteria of previous filters in a filter policy.
You can define one or more filters within the <appender> definition in the logging configuration file. Filters are not available in the logging facility language elements for SAS programs.
Filters are processed in the order in which they appear in the <appender> definition, creating a filtering policy for the appender. The filters either accept the filtering criteria and process the log event, deny the filtering criteria and deny the log event, or accept the filtering criteria, and the filtering process checks the next filter in the filtering policy. If the log event has not been denied, and if there are no other filters in the filtering policy, the appender accepts and processes the log event.
For more information, see Filters.