Module ch.qos.logback.classic
Package ch.qos.logback.classic.turbo

Class DynamicThresholdFilter

java.lang.Object
ch.qos.logback.core.spi.ContextAwareBase
ch.qos.logback.classic.turbo.TurboFilter
ch.qos.logback.classic.turbo.DynamicThresholdFilter
All Implemented Interfaces:
ContextAware, LifeCycle
public class DynamicThresholdFilter extends TurboFilter
This filter allows for efficient course grained filtering based on criteria such as product name or company name that would be associated with requests as they are processed.

This filter will allow you to associate threshold levels to a key put in the MDC. This key can be any value specified by the user. Furthermore, you can pass MDC value and level threshold associations, which are then looked up to find the level threshold to apply to the current logging request. If no level threshold could be found, then a 'default' value specified by the user is applied. We call this value 'levelAssociatedWithMDCValue'.

If 'levelAssociatedWithMDCValue' is higher or equal to the level of the current logger request, the decide() method returns the value of onHigherOrEqual, if it is lower than the value of onLower is returned. Both 'onHigherOrEqual' and 'onLower' can be set by the user. By default, 'onHigherOrEqual' is set to NEUTRAL and 'onLower' is set to DENY. Thus, if the current logger request's level is lower than 'levelAssociatedWithMDCValue', then the request is denied, and if it is higher or equal, then this filter decides NEUTRAL letting subsequent filters to make the decision on the fate of the logging request.

The example below illustrates how logging could be enabled for only individual users. In this example all events for logger names matching "com.mycompany" will be logged if they are for 'user1' and at a level higher than equals to DEBUG, and for 'user2' if they are at a level higher than or equal to TRACE, and for other users only if they are at level ERROR or higher. Events issued by loggers other than "com.mycompany" will only be logged if they are at level ERROR or higher since that is all the root logger allows. 

 <configuration>
   <appender name="STDOUT"
             class="ch.qos.logback.core.ConsoleAppender">
     <layout class="ch.qos.logback.classic.PatternLayout">
       <Pattern>TEST %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</Pattern>
     </layout>
   </appender>
   
   <turboFilter class="ch.qos.logback.classic.turbo.DynamicThresholdFilter">
     <Key>userId</Key>
     <DefaultThreshold>ERROR</DefaultThreshold>
     <MDCValueLevelPair>
       <value>user1</value>
       <level>DEBUG</level>
     </MDCValueLevelPair>
     <MDCValueLevelPair>
       <value>user2</value>
       <level>TRACE</level>
     </MDCValueLevelPair>
   </turboFilter>
   
   <logger name="com.mycompany" level="TRACE"/>
   
   <root level="ERROR" >
     <appender-ref ref="STDOUT" />
   </root>
 </configuration>
In the next configuration events from user1 and user2 will be logged regardless of the logger levels. Events for other users and records without a userid in the MDC will be logged if they are ERROR level messages. With this configuration, the root level is never checked since DynamicThresholdFilter will either accept or deny all records. 
 <configuration>
   <appender name="STDOUT"
             class="ch.qos.logback.core.ConsoleAppender">
     <layout class="ch.qos.logback.classic.PatternLayout">
        <Pattern>TEST %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</Pattern>
     </layout>
   </appender>
   
   <turboFilter class="ch.qos.logback.classic.turbo.DynamicThresholdFilter">
     <Key>userId</Key>
     <DefaultThreshold>ERROR</DefaultThreshold>
     <OnHigherOrEqual>ACCEPT</OnHigherOrEqual>
     <OnLower>DENY</OnLower>
     <MDCValueLevelPair>
       <value>user1</value>
       <level>TRACE</level>
     </MDCValueLevelPair>
     <MDCValueLevelPair>
       <value>user2</value>
       <level>TRACE</level>
     </MDCValueLevelPair>
   </turboFilter>
   
   <root level="DEBUG" >
     <appender-ref ref="STDOUT" />
   </root>
 </configuration>
Author:
Ralph Goers, Ceki Gülcü

  • Constructor Details

  • Method Details

    • getKey

      public String getKey()
      Get the MDC key whose value will be used as a level threshold
      Returns:
      the name of the MDC key.

    • setKey

      public void setKey(String key)
      See Also:

    • getDefaultThreshold

      public Level getDefaultThreshold()
      Get the default threshold value when the MDC key is not set.
      Returns:
      the default threshold value in the absence of a set MDC key

    • setDefaultThreshold

      public void setDefaultThreshold(Level defaultThreshold)

    • getOnHigherOrEqual

      public FilterReply getOnHigherOrEqual()
      Get the FilterReply when the effective level is higher or equal to the level of current logging request
      Returns:
      FilterReply

    • setOnHigherOrEqual

      public void setOnHigherOrEqual(FilterReply onHigherOrEqual)

    • getOnLower

      public FilterReply getOnLower()
      Get the FilterReply when the effective level is lower than the level of current logging request
      Returns:
      FilterReply

    • setOnLower

      public void setOnLower(FilterReply onLower)

    • addMDCValueLevelPair

      public void addMDCValueLevelPair(MDCValueLevelPair mdcValueLevelPair)
      Add a new MDCValuePair

    • start

      public void start()
      Specified by:
      start in interface LifeCycle
      Overrides:
      start in class TurboFilter

    • decide

      public FilterReply decide(org.slf4j.Marker marker, Logger logger, Level level, String s, Object[] objects, Throwable throwable)
      This method first finds the MDC value for 'key'. It then finds the level threshold associated with this MDC value from the list of MDCValueLevelPair passed to this filter. This value is stored in a variable called 'levelAssociatedWithMDCValue'. If it is null, then it is set to the
      Specified by:
      decide in class TurboFilter
      Parameters:
      marker -
      logger -
      level -
      s -
      objects -
      throwable -
      Returns:
      FilterReply - this filter's decision