From e26be1d85c1f01b764f13a3c912446c935e620a5 Mon Sep 17 00:00:00 2001
From: Xuan <xgong@apache.org>
Date: Wed, 5 Nov 2014 18:26:07 -0800
Subject: [PATCH] YARN-2813. Fixed NPE from MemoryTimelineStore.getDomains.
 Contributed by Zhijie Shen

---
 hadoop-yarn-project/CHANGES.txt                               | 2 ++
 .../hadoop/yarn/server/timeline/MemoryTimelineStore.java      | 4 ++++
 .../hadoop/yarn/server/timeline/TimelineStoreTestUtils.java   | 4 ++++
 3 files changed, 10 insertions(+)

diff --git a/hadoop-yarn-project/CHANGES.txt b/hadoop-yarn-project/CHANGES.txt
index 63eb6f2e551..8c7882fd7e1 100644
--- a/hadoop-yarn-project/CHANGES.txt
+++ b/hadoop-yarn-project/CHANGES.txt
@@ -845,6 +845,8 @@ Release 2.6.0 - UNRELEASED
     FatalEventDispatcher try to transition RM to StandBy at the same time.
     (Rohith Sharmaks via jianhe)
 
+    YARN-2813. Fixed NPE from MemoryTimelineStore.getDomains. (Zhijie Shen via xgong)
+
 Release 2.5.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-applicationhistoryservice/src/main/java/org/apache/hadoop/yarn/server/timeline/MemoryTimelineStore.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-applicationhistoryservice/src/main/java/org/apache/hadoop/yarn/server/timeline/MemoryTimelineStore.java
index 2d126b48a01..af714b17b80 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-applicationhistoryservice/src/main/java/org/apache/hadoop/yarn/server/timeline/MemoryTimelineStore.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-applicationhistoryservice/src/main/java/org/apache/hadoop/yarn/server/timeline/MemoryTimelineStore.java
@@ -241,6 +241,10 @@ public class MemoryTimelineStore
   public TimelineDomains getDomains(String owner)
       throws IOException {
     List<TimelineDomain> domains = new ArrayList<TimelineDomain>();
+    Set<TimelineDomain> domainsOfOneOwner = domainsByOwner.get(owner);
+    if (domainsOfOneOwner == null) {
+      return new TimelineDomains();
+    }
     for (TimelineDomain domain : domainsByOwner.get(owner)) {
       TimelineDomain domainToReturn = createTimelineDomain(
           domain.getId(),
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-applicationhistoryservice/src/test/java/org/apache/hadoop/yarn/server/timeline/TimelineStoreTestUtils.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-applicationhistoryservice/src/test/java/org/apache/hadoop/yarn/server/timeline/TimelineStoreTestUtils.java
index 868838e61d9..242478cafa9 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-applicationhistoryservice/src/test/java/org/apache/hadoop/yarn/server/timeline/TimelineStoreTestUtils.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-applicationhistoryservice/src/test/java/org/apache/hadoop/yarn/server/timeline/TimelineStoreTestUtils.java
@@ -946,6 +946,10 @@ public class TimelineStoreTestUtils {
     assertEquals(2, actualDomains.getDomains().size());
     verifyDomainInfo(domain3, actualDomains.getDomains().get(0));
     verifyDomainInfo(domain1, actualDomains.getDomains().get(1));
+
+    // owner without any domain
+    actualDomains = store.getDomains("owner_4");
+    assertEquals(0, actualDomains.getDomains().size());
   }
 
   private static void verifyDomainInfo(