title: log4j warning after `homebrew install zookeeper`
body: <p>I'm running Mac OS X 10. I just did <code>brew install zookeeper</code>.</p>
  
  <p>Then I created <code>/usr/local/etc/zookeeper/zoo.cfg</code> based on <code>/usr/local/etc/zookeeper/zoo_sample.cfg</code>.</p>
  
  <p>Then <code>zkServer start</code> works just fine.</p>
  
  <p>But, when trying to connect to Zookeeper from Clojure, which uses the Zookeeper Java client, I get this error:</p>
  
  <pre><code>log4j:WARN No appenders could be found for logger (org.apache.zookeeper.ZooKeeper).
  log4j:WARN Please initialize the log4j system properly.
  log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
  </code></pre>
  
  <p>My <code>log4j.properties</code> file:</p>
  
  <pre><code>log4j.rootCategory=WARN, zklog
  log4j.appender.zklog = org.apache.log4j.FileAppender
  log4j.appender.zklog.File = /usr/local/var/log/zookeeper/zookeeper.log
  log4j.appender.zklog.Append = true
  log4j.appender.zklog.layout = org.apache.log4j.PatternLayout
  log4j.appender.zklog.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss} %c{1} [%p] %m%n
  </code></pre>
  
  <p>So, my questions are:</p>
  
  <ol>
  <li>What is a reasonable log4j configuration for my situation?</li>
  <li>What could homebrew do, out of the box, to prevent this warning from happening?</li>
  </ol>