YARN-6221. Entities missing from ATS when summary log file info got returned to the ATS before the domain log. Contributed by Xiaomin Zhang

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timeline-pluginstorage/src/main/java/org/apache/hadoop/yarn/server/timeline/EntityGroupFSTimelineStore.java

@@ -808,11 +808,12 @@ public class EntityGroupFSTimelineStore extends CompositeService
       LogInfo log;
       if (isDomainLog) {
         log = new DomainLogInfo(attemptDirName, filename, owner);
+        summaryLogs.add(0, log);
       } else {
         log = new EntityLogInfo(attemptDirName, filename, owner);
-      }
         summaryLogs.add(log);
       }
+    }
 
     private synchronized void addDetailLog(String attemptDirName,
         String filename, String owner) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timeline-pluginstorage/src/test/java/org/apache/hadoop/yarn/server/timeline/TestEntityGroupFSTimelineStore.java

@@ -226,6 +226,31 @@ public class TestEntityGroupFSTimelineStore extends TimelineStoreTestUtils {
     }
   }
 
+  @Test
+  public void testAppLogsDomainLogLastlyScanned() throws Exception {
+    EntityGroupFSTimelineStore.AppLogs appLogs =
+            store.new AppLogs(mainTestAppId, mainTestAppDirPath,
+                    AppState.COMPLETED);
+    Path attemptDirPath = new Path(new Path(testActiveDirPath,
+            mainTestAppId.toString()),
+            getAttemptDirName(mainTestAppId));
+    //Delete the domain log from AppDirPath so first scan won't find it
+    fs.delete(new Path(attemptDirPath, TEST_DOMAIN_LOG_FILE_NAME), false);
+    appLogs.scanForLogs();
+    List<LogInfo> summaryLogs = appLogs.getSummaryLogs();
+    assertEquals(1, summaryLogs.size());
+    assertEquals(TEST_SUMMARY_LOG_FILE_NAME, summaryLogs.get(0).getFilename());
+
+    //Generate the domain log
+    FSDataOutputStream out = fs.create(
+            new Path(attemptDirPath, TEST_DOMAIN_LOG_FILE_NAME));
+    out.close();
+
+    appLogs.scanForLogs();
+    assertEquals(2, summaryLogs.size());
+    assertEquals(TEST_DOMAIN_LOG_FILE_NAME, summaryLogs.get(0).getFilename());
+  }
+
   @Test
   public void testMoveToDone() throws Exception {
     EntityGroupFSTimelineStore.AppLogs appLogs =