One can specify "-Dlog4j.configuration=<log4j.xml>" or "-Dlog4j.configuration=<log4j.properties>". Is there any preference to using one over other?
All the spark documentation talks about using "log4j.properties" only ( http://spark.apache.org/docs/latest/configuration.html#configuring-logging). So is only "log4j.properties" officially supported?
