From f3a95ed841129624015b23325a2cbb39ce556ce6 Mon Sep 17 00:00:00 2001
From: Karthik Kambatla <kasha@apache.org>
Date: Fri, 7 Mar 2014 21:34:51 +0000
Subject: [PATCH] YARN-1774. FS: Submitting to non-leaf queue throws NPE.
 (Anubhav Dhoot and Karthik Kambatla via kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1575417 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-yarn-project/CHANGES.txt               |  2 ++
 .../scheduler/fair/FairScheduler.java         | 35 +++++++++++++------
 .../scheduler/fair/TestFairScheduler.java     | 16 +++++++++
 3 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index 0e9c7088819..739464ed765 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -398,6 +398,8 @@ Release 2.4.0 - UNRELEASED
     YARN-1768. Fixed error message being too verbose when killing a non-existent
     application
     
+    YARN-1774. FS: Submitting to non-leaf queue throws NPE. (Anubhav Dhoot and
+    Karthik Kambatla via kasha)
 
 Release 2.3.1 - UNRELEASED
 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairScheduler.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairScheduler.java
index 9cc90bc7225..3cdff7f4055 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairScheduler.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/FairScheduler.java
@@ -611,9 +611,6 @@ public class FairScheduler extends AbstractYarnScheduler {
     RMApp rmApp = rmContext.getRMApps().get(applicationId);
     FSLeafQueue queue = assignToQueue(rmApp, queueName, user);
     if (queue == null) {
-      rmContext.getDispatcher().getEventHandler().handle(
-          new RMAppRejectedEvent(applicationId,
-              "Application rejected by queue placement policy"));
       return;
     }
 
@@ -679,27 +676,43 @@ public class FairScheduler extends AbstractYarnScheduler {
         new RMAppAttemptEvent(applicationAttemptId,
             RMAppAttemptEventType.ATTEMPT_ADDED));
   }
-  
+
+  /**
+   * Helper method that attempts to assign the app to a queue. The method is
+   * responsible to call the appropriate event-handler if the app is rejected.
+   */
   @VisibleForTesting
   FSLeafQueue assignToQueue(RMApp rmApp, String queueName, String user) {
     FSLeafQueue queue = null;
+    String appRejectMsg = null;
+
     try {
       QueuePlacementPolicy placementPolicy = allocConf.getPlacementPolicy();
       queueName = placementPolicy.assignAppToQueue(queueName, user);
       if (queueName == null) {
-        return null;
+        appRejectMsg = "Application rejected by queue placement policy";
+      } else {
+        queue = queueMgr.getLeafQueue(queueName, true);
+        if (queue == null) {
+          appRejectMsg = queueName + " is not a leaf queue";
+        }
       }
-      queue = queueMgr.getLeafQueue(queueName, true);
-    } catch (IOException ex) {
-      LOG.error("Error assigning app to queue, rejecting", ex);
+    } catch (IOException ioe) {
+      appRejectMsg = "Error assigning app to queue " + queueName;
     }
-    
+
+    if (appRejectMsg != null && rmApp != null) {
+      LOG.error(appRejectMsg);
+      rmContext.getDispatcher().getEventHandler().handle(
+          new RMAppRejectedEvent(rmApp.getApplicationId(), appRejectMsg));
+      return null;
+    }
+
     if (rmApp != null) {
       rmApp.setQueue(queue.getName());
     } else {
-      LOG.warn("Couldn't find RM app to set queue name on");
+      LOG.error("Couldn't find RM app to set queue name on");
     }
-    
     return queue;
   }
 
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairScheduler.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairScheduler.java
index a9444b8a177..993b3c54a65 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairScheduler.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/TestFairScheduler.java
@@ -704,6 +704,22 @@ public class TestFairScheduler {
     assertEquals(rmApp2.getQueue(), queue2.getName());
     assertEquals("root.notdefault", rmApp2.getQueue());
   }
+
+  @Test
+  public void testAssignToNonLeafQueueReturnsNull() throws Exception {
+    conf.set(FairSchedulerConfiguration.USER_AS_DEFAULT_QUEUE, "true");
+    scheduler.reinitialize(conf, resourceManager.getRMContext());
+
+    scheduler.getQueueManager().getLeafQueue("root.child1.granchild", true);
+    scheduler.getQueueManager().getLeafQueue("root.child2", true);
+
+    RMApp rmApp1 = new MockRMApp(0, 0, RMAppState.NEW);
+    RMApp rmApp2 = new MockRMApp(1, 1, RMAppState.NEW);
+
+    // Trying to assign to non leaf queue would return null
+    assertNull(scheduler.assignToQueue(rmApp1, "root.child1", "tintin"));
+    assertNotNull(scheduler.assignToQueue(rmApp2, "root.child2", "snowy"));
+  }
   
   @Test
   public void testQueuePlacementWithPolicy() throws Exception {