title: Mule Logging slf4j
body: <p>The Mule 3.3.x documentation here ( <a href="http://www.mulesoft.org/documentation/display/33X/Configuring+Logging" rel="nofollow">http://www.mulesoft.org/documentation/display/33X/Configuring+Logging</a> ) says that Mule uses slf4j as a facade for logging. Based on that, I expected to be able to delete log4j-1.2.16.jar from mule\lib\boot and add in log4j-api-2.0-beta7, log4j-core-2.0-beta7, log4j-slf4j-impl-2.0-beta7 to take advantage of log4j 2.0.  </p>
  
  <p>When I do this, I get an exception that org/apache/log4j/or/RendererMap cannot be found.</p>
  
  <p>Looking further, I do not find slf4j-api.jar anywhere in the Mule installation, a library I thought required to use slf4j.</p>
  
  <p>Is the Mule documentation incorrect or is there something else I need to do?</p>
  
  <p>Here's the truncated stacktrace from Mule.  For some reason, uncommenting the "-Dmule.verbose.exceptions=true" option in wrapper.conf isn't giving me full stacktraces.</p>
  
  <pre><code>Error in WrapperListener.start callback.  java.lang.NoClassDefFoundError: org/apache/log4j/or/RendererMap
  java.lang.NoClassDefFoundError: org/apache/log4j/or/RendererMap
      at org.apache.log4j.Hierarchy.&lt;init&gt;(Hierarchy.java:97)
      at org.apache.log4j.LogManager.&lt;clinit&gt;(LogManager.java:82)
      at org.apache.log4j.Logger.getLogger(Logger.java:117)
      at org.mule.module.launcher.log4j.ApplicationAwareRepositorySelector.&lt;init&gt;(ApplicationAwareRepositorySelector.java:44)
      at org.mule.module.launcher.MuleContainer.&lt;clinit&gt;(MuleContainer.java:85)
      at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
      at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
          at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
      at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
      at org.mule.module.reboot.MuleContainerWrapper.start(MuleContainerWrapper.java:54)
      at org.tanukisoftware.wrapper.WrapperManager$12.run(WrapperManager.java:2788)
  Caused by: java.lang.ClassNotFoundException: org.apache.log4j.or.RendererMap
      at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
      at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
      at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
      ... 11 more
  &lt;-- Wrapper Stopped
  </code></pre>