From 74a5e683fe65ee624a094de77940a42777ed7a26 Mon Sep 17 00:00:00 2001
From: bibinchundatt <bibinchundatt@apache.org>
Date: Mon, 22 Oct 2018 15:59:14 +0530
Subject: [PATCH] MAPREDUCE-7151. RMContainerAllocator#handleJobPriorityChange
 expects application_priority always. Contributed by Bilwa S T.

---
 .../mapreduce/v2/app/rm/RMContainerAllocator.java  | 14 ++++++++------
 .../v2/app/rm/TestRMContainerAllocator.java        | 14 ++++++++++++++
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/rm/RMContainerAllocator.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/rm/RMContainerAllocator.java
index 9d030b84e98..e459cb52f05 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/rm/RMContainerAllocator.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/rm/RMContainerAllocator.java
@@ -1020,12 +1020,14 @@ public class RMContainerAllocator extends RMContainerRequestor
     }
   }
 
-  private void handleJobPriorityChange(AllocateResponse response) {
-    Priority priorityFromResponse = Priority.newInstance(response
-        .getApplicationPriority().getPriority());
-
-    // Update the job priority to Job directly.
-    getJob().setJobPriority(priorityFromResponse);
+  void handleJobPriorityChange(AllocateResponse response) {
+    Priority applicationPriority = response.getApplicationPriority();
+    if (null != applicationPriority) {
+      Priority priorityFromResponse = Priority
+          .newInstance(applicationPriority.getPriority());
+      // Update the job priority to Job directly.
+      getJob().setJobPriority(priorityFromResponse);
+    }
   }
 
   @Private
diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/rm/TestRMContainerAllocator.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/rm/TestRMContainerAllocator.java
index 427e6ea228f..ad00bd651bd 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/rm/TestRMContainerAllocator.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/test/java/org/apache/hadoop/mapreduce/v2/app/rm/TestRMContainerAllocator.java
@@ -2160,6 +2160,20 @@ public class TestRMContainerAllocator {
     }
   }
 
+  @Test
+  public void testIfApplicationPriorityIsNotSet() {
+    Job mockJob = mock(Job.class);
+    RMCommunicator communicator = mock(RMCommunicator.class);
+    ClientService service = mock(ClientService.class);
+    AppContext context = mock(AppContext.class);
+    AMPreemptionPolicy policy = mock(AMPreemptionPolicy.class);
+    when(communicator.getJob()).thenReturn(mockJob);
+    RMContainerAllocator allocator = new RMContainerAllocator(service, context,
+        policy);
+    AllocateResponse response = Records.newRecord(AllocateResponse.class);
+    allocator.handleJobPriorityChange(response);
+  }
+
   @Test
   public void testReduceScheduling() throws Exception {
     int totalMaps = 10;