Minor style clean-up

core/src/main/scala/org/apache/spark/deploy/client/DriverClient.scala

@@ -101,6 +101,8 @@ object DriverClient {
   def main(args: Array[String]) {
     val driverArgs = new DriverClientArguments(args)
 
+    // TODO: See if we can initialize akka so return messages are sent back using the same TCP
+    //       flow. Else, this (sadly) requires the DriverClient be routable from the Master.
     val (actorSystem, boundPort) = AkkaUtils.createActorSystem(
       "driverClient", Utils.localHostName(), 0)
 

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

@@ -185,7 +185,7 @@ private[spark] class Master(host: String, port: Int, webUiPort: Int) extends Act
         schedule()
 
         // TODO: It might be good to instead have the submission client poll the master to determine
-        //       the current status of the driver. Since we may already want to expose this.
+        //       the current status of the driver. For now it's simply "fire and forget".
 
         sender ! SubmitDriverResponse(true, "Driver successfully submitted")
       }
@@ -611,7 +611,6 @@ private[spark] class Master(host: String, port: Int, webUiPort: Int) extends Act
     }
   }
 
-  /** Generate a new driver ID given a driver's submission date */
   def newDriverId(submitDate: Date): String = {
     val appId = "driver-%s-%04d".format(DATE_FORMAT.format(submitDate), nextDriverNumber)
     nextDriverNumber += 1

core/src/main/scala/org/apache/spark/deploy/master/ui/IndexPage.scala

@@ -106,20 +106,20 @@ private[spark] class IndexPage(parent: MasterWebUI) {
           </div>
         </div>
 
-          <div class="row-fluid">
-            <div class="span12">
-              <h4> Active Drivers </h4>
+        <div class="row-fluid">
+          <div class="span12">
+            <h4> Active Drivers </h4>
 
-              {activeDriversTable}
-            </div>
+            {activeDriversTable}
           </div>
+        </div>
 
-          <div class="row-fluid">
-            <div class="span12">
-              <h4> Completed Drivers </h4>
-              {completedDriversTable}
-            </div>
-          </div>;
+        <div class="row-fluid">
+          <div class="span12">
+            <h4> Completed Drivers </h4>
+            {completedDriversTable}
+          </div>
+        </div>;
     UIUtils.basicSparkPage(content, "Spark Master at " + state.uri)
   }
 

core/src/main/scala/org/apache/spark/deploy/worker/DriverRunner.scala

@@ -32,7 +32,7 @@ import org.apache.spark.deploy.master.DriverState
 import org.apache.spark.util.Utils
 
 /**
- * Manages the execution of one driver process.
+ * Manages the execution of one driver, including automatically restarting the driver on failure.
  */
 private[spark] class DriverRunner(
     val driverId: String,
@@ -133,7 +133,7 @@ private[spark] class DriverRunner(
     localJarFilename
   }
 
-  /** Continue launching the supplied command until it exits zero. */
+  /** Continue launching the supplied command until it exits zero or is killed. */
   def runCommandWithRetry(command: Seq[String], envVars: Seq[(String, String)], baseDir: File) = {
     // Time to wait between submission retries.
     var waitSeconds = 1

core/src/main/scala/org/apache/spark/deploy/worker/Worker.scala

@@ -254,17 +254,14 @@ private[spark] class Worker(
 
     case KillDriver(driverId) => {
       logInfo(s"Asked to kill driver $driverId")
-
       drivers.find(_._1 == driverId) match {
         case Some((id, runner)) =>
           runner.kill()
         case None =>
           logError(s"Asked to kill unknown driver $driverId")
       }
-
     }
 
-
     case DriverStateChanged(driverId, state, exception) => {
       state match {
         case DriverState.FAILED =>

examples/src/main/scala/org/apache/spark/examples/DriverSubmissionTest.scala

@@ -39,6 +39,7 @@ object DriverSubmissionTest {
     properties.filter{case (k, v) => k.toString.contains("spark.test")}.foreach(println)
 
     for (i <- 1 until numSecondsToSleep) {
+      println(s"Alive for $i out of $numSecondsToSleep seconds")
       Thread.sleep(1000)
     }
   }