[LOG4J2-2130] AppenderRef 'level' vs 'ThresholdFilter'

• Type: Question
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 2.10.0
• Component/s: Appenders
• Assignee: Unassigned
• Reporter: Joris van Heesch
• Created: 27/Nov/17 08:33
• Updated: 27/Nov/17 08:57

Description

Is there a significant difference between the following two configurations, i.e. are there certain elements to consider in choosing one over the other?
1.

<AppenderRef ref="out">
    <ThresholdFilter level="anyValidLevel"/>
</AppenderRef>

2.

<AppenderRef ref="out" level="anyValidLevel"/>

I looked at the class AppenderControl, and noticed that - to my surprise - shouldSkip() checks isFilteredByAppenderControl() before isFilteredByLevel().
I also noticed both these methods are annotated with @PerformanceSensitive, but I don't know if any of this is relevant.