merge -c r1460064 from trunk to branch-2 for YARN-417. Addendum patch (Sandy Ryza via bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1460065 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -394,6 +394,10 @@ public class ApplicationMaster {
         "container_memory", "10"));
     numTotalContainers = Integer.parseInt(cliParser.getOptionValue(
         "num_containers", "1"));
+    if (numTotalContainers == 0) {
+      throw new IllegalArgumentException(
+          "Cannot run distributed shell with no containers");
+    }
     requestPriority = Integer.parseInt(cliParser
         .getOptionValue("priority", "0"));
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-unmanaged-am-launcher/src/test/java/org/apache/hadoop/yarn/applications/unmanagedamlauncher/TestUnmanagedAMLauncher.java

@@ -91,7 +91,7 @@ public class TestUnmanagedAMLauncher {
     return envClassPath;
   }
 
-  @Test
+  @Test(timeout=10000)
   public void testDSShell() throws Exception {
     String classpath = getTestRuntimeClasspath();
     String javaHome = System.getenv("JAVA_HOME");
@@ -110,7 +110,7 @@ public class TestUnmanagedAMLauncher {
         javaHome
             + "/bin/java -Xmx512m "
             + "org.apache.hadoop.yarn.applications.distributedshell.ApplicationMaster "
-            + "--container_memory 128 --num_containers 0 --priority 0 --shell_command ls" };
+            + "--container_memory 128 --num_containers 1 --priority 0 --shell_command ls" };
 
     LOG.info("Initializing Launcher");
     UnmanagedAMLauncher launcher = new UnmanagedAMLauncher(new Configuration(