Feedback.

core/src/main/scala/org/apache/spark/deploy/history/FsHistoryProvider.scala

@@ -126,7 +126,7 @@ private[history] class FsHistoryProvider(conf: SparkConf, clock: Clock)
 
   private val storePath = conf.get(LOCAL_STORE_DIR)
 
-  private val listing = storePath.map { path =>
+  private val listing: KVStore = storePath.map { path =>
     val dbPath = new File(path, "listing.ldb")
 
     def openDB(): LevelDB = new LevelDB(dbPath, new KVStoreScalaSerializer())
@@ -334,10 +334,13 @@ private[history] class FsHistoryProvider(conf: SparkConf, clock: Clock)
   }
 
   override def stop(): Unit = {
-    listing.close()
-    if (initThread != null && initThread.isAlive()) {
-      initThread.interrupt()
-      initThread.join()
+    try {
+      if (initThread != null && initThread.isAlive()) {
+        initThread.interrupt()
+        initThread.join()
+      }
+    } finally {
+      listing.close()
     }
   }
 
@@ -362,7 +365,6 @@ private[history] class FsHistoryProvider(conf: SparkConf, clock: Clock)
             SparkHadoopUtil.get.checkAccessPermission(entry, FsAction.READ) &&
             recordedFileSize(entry.getPath()) < entry.getLen()
         }
-        .flatMap { entry => Some(entry) }
         .sortWith { case (entry1, entry2) =>
           entry1.getModificationTime() > entry2.getModificationTime()
         }
@@ -788,7 +790,7 @@ private[history] class AppListingListener(log: FileStatus, clock: Clock) extends
 
   def applicationInfo: Option[ApplicationInfoWrapper] = {
     if (app.id != null) {
-      Some(app.toView(List(attempt.toView())))
+      Some(app.toView())
     } else {
       None
     }
@@ -802,10 +804,10 @@ private[history] class AppListingListener(log: FileStatus, clock: Clock) extends
     var coresPerExecutor: Option[Int] = None
     var memoryPerExecutorMB: Option[Int] = None
 
-    def toView(attempts: List[AttemptInfoWrapper]): ApplicationInfoWrapper = {
+    def toView(): ApplicationInfoWrapper = {
       val apiInfo = new v1.ApplicationInfo(id, name, coresGranted, maxCores, coresPerExecutor,
         memoryPerExecutorMB, Nil)
-      new ApplicationInfoWrapper(apiInfo, attempts)
+      new ApplicationInfoWrapper(apiInfo, List(attempt.toView()))
     }
 
   }