Merge pull request #351 from pwendell/maven-fix

Add log4j exclusion rule to maven.

To make this work I had to rename the defaults file. Otherwise
maven's pattern matching rules included it when trying to match
other log4j.properties files.

I also fixed a bug in the existing maven build where two
<transformers> tags were present in assembly/pom.xml
such that one overwrote the other.

assembly/pom.xml

@@ -108,12 +108,12 @@
                 <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                   <resource>META-INF/services/org.apache.hadoop.fs.FileSystem</resource>
                 </transformer>
-              </transformers>
-              <transformers>
-                <transformer implementation="org.apache.maven.plugins.shade.resource.ServicesResourceTransformer" />
                 <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                   <resource>reference.conf</resource>
                 </transformer>
+                <transformer implementation="org.apache.maven.plugins.shade.resource.DontIncludeResourceTransformer">
+                  <resource>log4j.properties</resource>
+                </transformer>
               </transformers>
             </configuration>
           </execution>

core/src/main/scala/org/apache/spark/Logging.scala

@@ -104,13 +104,15 @@ trait Logging {
     // If Log4j doesn't seem initialized, load a default properties file
     val log4jInitialized = LogManager.getRootLogger.getAllAppenders.hasMoreElements
     if (!log4jInitialized) {
-      val defaultLogProps = "org/apache/spark/default-log4j.properties"
+      val defaultLogProps = "org/apache/spark/log4j-defaults.properties"
       val classLoader = this.getClass.getClassLoader
       Option(classLoader.getResource(defaultLogProps)) match {
-        case Some(url) => PropertyConfigurator.configure(url)
-        case None => System.err.println(s"Spark was unable to load $defaultLogProps")
+        case Some(url) => 
+          PropertyConfigurator.configure(url)
+          log.info(s"Using Spark's default log4j profile: $defaultLogProps")
+        case None => 
+          System.err.println(s"Spark was unable to load $defaultLogProps")
       }
-      log.info(s"Using Spark's default log4j profile: $defaultLogProps")
     }
     Logging.initialized = true
 

examples/pom.xml

@@ -203,6 +203,9 @@
                 <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                   <resource>reference.conf</resource>
                 </transformer>
+                <transformer implementation="org.apache.maven.plugins.shade.resource.DontIncludeResourceTransformer">
+                  <resource>log4j.properties</resource>
+                </transformer>
               </transformers>
             </configuration>
           </execution>