small changes with sean owen's comments

Author: liyezhang556520

core/src/main/scala/org/apache/spark/deploy/master/Master.scala

@@ -764,9 +764,10 @@ private[spark] class Master(
       val replayBus = new ReplayListenerBus()
       val ui = SparkUI.createHistoryUI(new SparkConf, replayBus, new SecurityManager(conf),
         appName + status, HistoryServer.UI_PATH_PREFIX + s"/${app.id}")
+      val maybeTruncated = eventLogFile.endsWith(EventLoggingListener.IN_PROGRESS)
       try {
         replayBus.replay(logInput, eventLogFile, 
-          eventLogFile.endsWith(EventLoggingListener.IN_PROGRESS))
+          maybeTruncated)
       } finally {
         logInput.close()
       }

core/src/main/scala/org/apache/spark/scheduler/ReplayListenerBus.scala

@@ -41,13 +41,13 @@ private[spark] class ReplayListenerBus extends SparkListenerBus with Logging {
    *
    * @param logData Stream containing event log data.
    * @param sourceName Filename (or other source identifier) from whence @logData is being read
-   * @param sourceTruncated Indicate whether log file might be truncated (some abnormal situation 
-   *        encountered, log file not finish writing) or not
+   * @param maybeTruncated Indicate whether log file might be truncated (some abnormal situations 
+   *        encountered, log file might not finished writing) or not
    */
   def replay(
       logData: InputStream,
       sourceName: String,
-      sourceTruncated: Boolean = false): Unit = {
+      maybeTruncated: Boolean = false): Unit = {
     var currentLine: String = null
     var lineNumber: Int = 1
     try {
@@ -59,11 +59,11 @@ private[spark] class ReplayListenerBus extends SparkListenerBus with Logging {
         } catch {
           case jpe: JsonParseException =>
             // We can only ignore exception from last line of the file that might be truncated
-            if (!sourceTruncated || lines.hasNext) {
+            if (!maybeTruncated || lines.hasNext) {
               throw jpe
             } else {
-              logWarning(s"Get json parse exception from log file $sourceName" + 
-                s" in line $lineNumber, the file might not finished writing.")
+              logWarning(s"Got JsonParseException from log file $sourceName" + 
+                s" at line $lineNumber, the file might not have finished writing cleanly.")
             }
         }
         lineNumber += 1