[LOG4J2-1911] DynamicThresholdFilter defaultThreshold is not used to compare against event's level when there's no matching key found.

• Type: Documentation
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.8.2
• Component/s: Filters
• Labels: documentation patch
• Assignee: Ralph Goers
• Reporter: Jerry Chin
• Created: 18/May/17 06:07
• Updated: 27/May/17 06:54
• Resolved: 27/May/17 06:54

Description

The defaultThreshold property is not honored as documented :

defaultThreshold Level of messages to be filtered. If there is no matching key in the key/value pairs then this level will be compared against the event's level.

after carefully examining the source code, I found the following code is called:

DynamicThresholdFilter.java

 private Result filter(Level level, ReadOnlyStringMap contextMap) {
        String value = (String)contextMap.getValue(this.key);
        if(value != null) {
            Level ctxLevel = (Level)this.levelMap.get(value);
            if(ctxLevel == null) {
                ctxLevel = this.defaultThreshold;
            }

            return level.isMoreSpecificThan(ctxLevel)?this.onMatch:this.onMismatch;
        } else {
            return Result.NEUTRAL;
        }
    }

where level is the event's level, when there's no matching key found contextMap, Result.NEUTRAL is mistakenly returned, instead of against this.defaultThreshold.