It will utilize commons-logging (it is in dependency tree) according to https://spring.io/blog/2009/12/04/logging-dependencies-in-spring/
"The nice thing about commons-logging is that you don’t need anything else to make your application work. It has a runtime discovery algorithm that looks for other logging frameworks in well known places on the classpath and uses one that it thinks is appropriate (or you can tell it which one if you need to). If nothing else is available you get pretty nice looking logs just from the JDK (java.util.logging or JUL for short). You should find that your Spring application works and logs happily to the console out of the box in most situations, and that’s important." Thanks, Alexey -- Sent from: http://apache-ignite-developers.2346864.n4.nabble.com/
