YARN-3793. Several NPEs when deleting local files on NM recovery. Contributed by Varun Saxena

(cherry picked from commit b5cdf78e8e)

hadoop-yarn-project/CHANGES.txt

@@ -550,6 +550,9 @@ Release 2.7.2 - UNRELEASED
 
   BUG FIXES
 
+    YARN-3793. Several NPEs when deleting local files on NM recovery (Varun
+    Saxena via jlowe)
+
 Release 2.7.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/main/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/logaggregation/AppLogAggregatorImpl.java

@@ -276,10 +276,10 @@ public class AppLogAggregatorImpl implements AppLogAggregator {
             aggregator.doContainerLogAggregation(writer, appFinished);
         if (uploadedFilePathsInThisCycle.size() > 0) {
           uploadedLogsInThisCycle = true;
+          this.delService.delete(this.userUgi.getShortUserName(), null,
+              uploadedFilePathsInThisCycle
+                  .toArray(new Path[uploadedFilePathsInThisCycle.size()]));
         }
-        this.delService.delete(this.userUgi.getShortUserName(), null,
-          uploadedFilePathsInThisCycle
-            .toArray(new Path[uploadedFilePathsInThisCycle.size()]));
 
         // This container is finished, and all its logs have been uploaded,
         // remove it from containerLogAggregators.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-nodemanager/src/test/java/org/apache/hadoop/yarn/server/nodemanager/containermanager/logaggregation/TestLogAggregationService.java

@@ -31,6 +31,7 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
@@ -280,6 +281,41 @@ public class TestLogAggregationService extends BaseContainerManagerTest {
     verifyLocalFileDeletion(logAggregationService);
   }
 
+  /* Test to verify fix for YARN-3793 */
+  @Test
+  public void testNoLogsUploadedOnAppFinish() throws Exception {
+    this.delSrvc = new DeletionService(createContainerExecutor());
+    delSrvc = spy(delSrvc);
+    this.delSrvc.init(conf);
+    this.conf.set(YarnConfiguration.NM_LOG_DIRS, localLogDir.getAbsolutePath());
+    this.conf.set(YarnConfiguration.NM_REMOTE_APP_LOG_DIR,
+        this.remoteRootLogDir.getAbsolutePath());
+
+    LogAggregationService logAggregationService = new LogAggregationService(
+        dispatcher, this.context, this.delSrvc, super.dirsHandler);
+    logAggregationService.init(this.conf);
+    logAggregationService.start();
+
+    ApplicationId app = BuilderUtils.newApplicationId(1234, 1);
+    File appLogDir = new File(localLogDir, ConverterUtils.toString(app));
+    appLogDir.mkdir();
+    LogAggregationContext context =
+        LogAggregationContext.newInstance("HOST*", "sys*");
+    logAggregationService.handle(new LogHandlerAppStartedEvent(app, this.user,
+        null, ContainerLogsRetentionPolicy.ALL_CONTAINERS, this.acls, context));
+
+    ApplicationAttemptId appAttemptId =
+        BuilderUtils.newApplicationAttemptId(app, 1);
+    ContainerId cont = BuilderUtils.newContainerId(appAttemptId, 1);
+    writeContainerLogs(appLogDir, cont, new String[] { "stdout",
+        "stderr", "syslog" });
+    logAggregationService.handle(new LogHandlerContainerFinishedEvent(cont, 0));
+    logAggregationService.handle(new LogHandlerAppFinishedEvent(app));
+    logAggregationService.stop();
+    delSrvc.stop();
+    // Aggregated logs should not be deleted if not uploaded.
+    verify(delSrvc, times(0)).delete(user, null);
+  }
 
   @Test
   public void testNoContainerOnNode() throws Exception {