log4j2: Location for setting Log4jContextSelector system property for asynchronous logging

Question

I am attempting to set up asynchronous logging (for performance reasons) within REST web methods that currently run in a liberty profile server.

In order to do this, I h

Answer 1

There is an undocumented method of setting this value for your project without having to manually pass in the system property value during start up.

Add a file named log4j2.component.properties to your classpath. This can be done in most maven or gradle projects by saving it in src/main/resources.

This is file is simply java.util.Properties file. Set the value for the context selector by adding the following line to the file.

Log4jContextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector

Log4j will attempt to read the system property first. If the system property is null, then it will fall back to the values stored in this file by default.

The code that performs this setup is located at Log4jContextFactory.java:91.