Major Description
Poking around the code I noticed that HBase uses log4j while most of crunch-core, crunch-spark use commons-logging. If the variation is justified that is fine but for consumer wanting to consistently configure logging for Crunch jobs it would be nice to use a consistent API and then let them configure it one way.
Our options are possibly to converge on one implementation or move to something like slf4j and allow consumers to swap out the impl at assembly time.