geode-core ships with a log4j2.xml at the standard location which means that it is a candidate for bootstraping the logging infrastructure of any app using that library. See also #
This is a problem when embedding this library in application that relies on the absence of such a file to derive a sensible default configuration (typically a Spring Boot app).
In general, the hard dependency on log4j is a bit annoying for the embedded use case. There is more context available here: https://github.com/spring-projects/spring-boot-data-geode/issues/42