YARN-4354. Public resource localization fails with NPE. Contributed by Jason Lowe.

(cherry picked from commit 855d52927b)

hadoop-yarn-project/CHANGES.txt

@@ -1129,6 +1129,9 @@ Release 2.7.2 - UNRELEASED
     YARN-4320. TestJobHistoryEventHandler fails as AHS in MiniYarnCluster no longer
     binds to default port 8188. (Varun Saxena via ozawa)
 
+    YARN-4354. Public resource localization fails with NPE. (Jason Lowe via 
+    junping_du)
+
 Release 2.7.1 - 2015-07-06
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/localizer/LocalResourcesTrackerImpl.java

@@ -185,14 +185,22 @@ public synchronized void handle(ResourceEvent event) {
       break;
     }
 
+    if (rsrc == null) {
+      LOG.warn("Received " + event.getType() + " event for request " + req
+          + " but localized resource is missing");
+      return;
+    }
     rsrc.handle(event);
 
     // Remove the resource if its downloading and its reference count has
     // become 0 after RELEASE. This maybe because a container was killed while
     // localizing and no other container is referring to the resource.
+    // NOTE: This should NOT be done for public resources since the
+    //       download is not associated with a container-specific localizer.
     if (event.getType() == ResourceEventType.RELEASE) {
       if (rsrc.getState() == ResourceState.DOWNLOADING &&
-          rsrc.getRefCount() <= 0) {
+          rsrc.getRefCount() <= 0 &&
+          rsrc.getRequest().getVisibility() != LocalResourceVisibility.PUBLIC) {
         removeResource(req);
       }
     }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/localizer/TestLocalResourcesTrackerImpl.java

@@ -141,12 +141,12 @@ public void test() {
       tracker.handle(rel21Event);
 
       dispatcher.await();
-      verifyTrackedResourceCount(tracker, 1);
+      verifyTrackedResourceCount(tracker, 2);
 
       // Verify resource with non zero ref count is not removed.
       Assert.assertEquals(2, lr1.getRefCount());
       Assert.assertFalse(tracker.remove(lr1, mockDelService));
-      verifyTrackedResourceCount(tracker, 1);
+      verifyTrackedResourceCount(tracker, 2);
 
       // Localize resource1
       ResourceLocalizedEvent rle =
@@ -161,7 +161,7 @@ public void test() {
 
       // Verify resources in state LOCALIZED with ref-count=0 is removed.
       Assert.assertTrue(tracker.remove(lr1, mockDelService));
-      verifyTrackedResourceCount(tracker, 0);
+      verifyTrackedResourceCount(tracker, 1);
     } finally {
       if (dispatcher != null) {
         dispatcher.stop();
@@ -899,6 +899,56 @@ public void testResourcePresentInGoodDir() throws IOException {
     }
   }
 
+  @Test
+  @SuppressWarnings("unchecked")
+  public void testReleaseWhileDownloading() throws Exception {
+    String user = "testuser";
+    DrainDispatcher dispatcher = null;
+    try {
+      Configuration conf = new Configuration();
+      dispatcher = createDispatcher(conf);
+      EventHandler<LocalizerEvent> localizerEventHandler =
+          mock(EventHandler.class);
+      EventHandler<LocalizerEvent> containerEventHandler =
+          mock(EventHandler.class);
+      dispatcher.register(LocalizerEventType.class, localizerEventHandler);
+      dispatcher.register(ContainerEventType.class, containerEventHandler);
+
+      ContainerId cId = BuilderUtils.newContainerId(1, 1, 1, 1);
+      LocalizerContext lc = new LocalizerContext(user, cId, null);
+
+      LocalResourceRequest req =
+          createLocalResourceRequest(user, 1, 1, LocalResourceVisibility.PUBLIC);
+      LocalizedResource lr = createLocalizedResource(req, dispatcher);
+      ConcurrentMap<LocalResourceRequest, LocalizedResource> localrsrc =
+          new ConcurrentHashMap<LocalResourceRequest, LocalizedResource>();
+      localrsrc.put(req, lr);
+      LocalResourcesTracker tracker =
+          new LocalResourcesTrackerImpl(user, null, dispatcher, localrsrc,
+              false, conf, new NMNullStateStoreService(), null);
+
+      // request the resource
+      ResourceEvent reqEvent =
+          new ResourceRequestEvent(req, LocalResourceVisibility.PUBLIC, lc);
+      tracker.handle(reqEvent);
+
+      // release the resource
+      ResourceEvent relEvent = new ResourceReleaseEvent(req, cId);
+      tracker.handle(relEvent);
+
+      // download completing after release
+      ResourceLocalizedEvent rle =
+          new ResourceLocalizedEvent(req, new Path("file:///tmp/r1"), 1);
+      tracker.handle(rle);
+
+      dispatcher.await();
+    } finally {
+      if (dispatcher != null) {
+        dispatcher.stop();
+      }
+    }
+  }
+
   private boolean createdummylocalizefile(Path path) {
     boolean ret = false;
     File file = new File(path.toUri().getRawPath().toString());

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/localizer/TestResourceLocalizationService.java

@@ -487,8 +487,8 @@ public void testResourceRelease() throws Exception {
         Assert.assertEquals("Incorrect reference count", 0, lr.getRefCount());
         pubRsrcs.remove(lr.getRequest());
       }
-      Assert.assertEquals(2, pubRsrcs.size());
-      Assert.assertEquals(0, pubRsrcCount);
+      Assert.assertEquals(0, pubRsrcs.size());
+      Assert.assertEquals(2, pubRsrcCount);
 
       appRsrcCount = 0;
       for (LocalizedResource lr : appTracker) {