spring boot fails to set logging level correctly while using log4j2 instead of logback

[c3y28]

• Spring Boot 2.1.x.RELEASE
• JUL as logging API
• Oracle JDK 11.0.4 or Oracle JDK 1.8.0_221

setting logging level to TRACE in application.properties but not take effect. Actually logging.properties under working JAVA_HOME takes effect

if using default logging.properties, we will find missing these level items in log(config, fine, finer, finest)

please find the attached for a simple demo to reproduce the issue.
spring-boot-logging-demo.zip

[wilkinsona]

Thank you for the sample. To route all JUL logging into Log4j2 you need to set a system property as described in the usage section of their documentation. There's a mention of this in Boot's documentation as well. Given the use of a system property I'm still (#2923 (comment)) wary of enabling this by default so I don't think there's much more that we can do here.