Merge -r 1362721:1362722 from trunk to branch. FIXES: MAPREDUCE-4422

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1362723 13f79535-47bb-0310-9956-ffa450edef68

hadoop-mapreduce-project/CHANGES.txt

@@ -1,5 +1,8 @@
 Hadoop MapReduce Change Log
 
+    MAPREDUCE-4422. YARN_APPLICATION_CLASSPATH needs a documented default value in 
+    YarnConfiguration. (ahmed via tucu)
+
 Release 2.1.0-alpha - Unreleased 
 
   INCOMPATIBLE CHANGES

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-common/src/main/java/org/apache/hadoop/mapreduce/v2/util/MRApps.java

@@ -171,8 +171,9 @@ public class MRApps extends Apps {
       }
 
       // Add standard Hadoop classes
-      for (String c : conf.get(YarnConfiguration.YARN_APPLICATION_CLASSPATH)
-          .split(",")) {
+      for (String c : conf.getStrings(
+          YarnConfiguration.YARN_APPLICATION_CLASSPATH,
+          YarnConfiguration.DEFAULT_YARN_APPLICATION_CLASSPATH)) {
         Apps.addToEnvironment(environment, Environment.CLASSPATH.name(), c
             .trim());
       }

hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/main/java/org/apache/hadoop/yarn/applications/distributedshell/Client.java

@@ -508,8 +508,9 @@ public class Client {
     // For now setting all required classpaths including
     // the classpath to "." for the application jar
     StringBuilder classPathEnv = new StringBuilder("${CLASSPATH}:./*");
-    for (String c : conf.get(YarnConfiguration.YARN_APPLICATION_CLASSPATH)
-        .split(",")) {
+    for (String c : conf.getStrings(
+        YarnConfiguration.YARN_APPLICATION_CLASSPATH,
+        YarnConfiguration.DEFAULT_YARN_APPLICATION_CLASSPATH)) {
       classPathEnv.append(':');
       classPathEnv.append(c.trim());
     }

hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/conf/YarnConfiguration.java

@@ -541,10 +541,25 @@ public class YarnConfiguration extends Configuration {
   public static final long DEFAULT_NM_PROCESS_KILL_WAIT_MS =
       2000;
 
-  /** Standard Hadoop classes */
+  /**
+   * CLASSPATH for YARN applications. A comma-separated list of CLASSPATH
+   * entries
+   */
   public static final String YARN_APPLICATION_CLASSPATH = YARN_PREFIX
       + "application.classpath";
 
+  /**
+   * Default CLASSPATH for YARN applications. A comma-separated list of
+   * CLASSPATH entries
+   */
+  public static final String[] DEFAULT_YARN_APPLICATION_CLASSPATH = {
+      "$HADOOP_CONF_DIR", "$HADOOP_COMMON_HOME/share/hadoop/common/*",
+      "$HADOOP_COMMON_HOME/share/hadoop/common/lib/*",
+      "$HADOOP_HDFS_HOME/share/hadoop/hdfs/*",
+      "$HADOOP_HDFS_HOME/share/hadoop/hdfs/lib/*",
+      "$YARN_HOME/share/hadoop/mapreduce/*",
+      "$YARN_HOME/share/hadoop/mapreduce/lib/*"};
+
   /** Container temp directory */
   public static final String DEFAULT_CONTAINER_TEMP_DIR = "./tmp";
 

hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-common/src/main/resources/yarn-default.xml

@@ -538,16 +538,9 @@
   </property>
 
   <property>
-    <description>Classpath for typical applications.</description>
+    <description>CLASSPATH for YARN applications. A comma-separated list
+    of CLASSPATH entries</description>
      <name>yarn.application.classpath</name>
-     <value>
-        $HADOOP_CONF_DIR,
-        $HADOOP_COMMON_HOME/share/hadoop/common/*,
-        $HADOOP_COMMON_HOME/share/hadoop/common/lib/*,
-        $HADOOP_HDFS_HOME/share/hadoop/hdfs/*,
-        $HADOOP_HDFS_HOME/share/hadoop/hdfs/lib/*,
-        $YARN_HOME/share/hadoop/mapreduce/*,
-        $YARN_HOME/share/hadoop/mapreduce/lib/*
-     </value>
+     <value>$HADOOP_CONF_DIR,$HADOOP_COMMON_HOME/share/hadoop/common/*,$HADOOP_COMMON_HOME/share/hadoop/common/lib/*,$HADOOP_HDFS_HOME/share/hadoop/hdfs/*,$HADOOP_HDFS_HOME/share/hadoop/hdfs/lib/*,$YARN_HOME/share/hadoop/mapreduce/*,$YARN_HOME/share/hadoop/mapreduce/lib/*</value>
   </property>
 </configuration>