I wonder if it would make sense to replace log4j-1.2.15.jar in the lib directory of the cloud branch with log4j-over-slf4j-1.5.5.jar. SOLR is already using SLF4J for its logging and log4j-over-slf4j bridge would redirect all ZooKeeper log messages into the same SLF4J logging stream. I did it in my setup and and it helped me a lot when I ran into issues with my ZooKeeper configuration.
Thank you, Igor
