Merge pull request #280 from aarondav/minor

Minor cleanup for standalone scheduler

See commit messages

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

@@ -61,8 +61,6 @@ private[spark] class Master(host: String, port: Int, webUiPort: Int) extends Act
   val waitingApps = new ArrayBuffer[ApplicationInfo]
   val completedApps = new ArrayBuffer[ApplicationInfo]
 
-  var firstApp: Option[ApplicationInfo] = None
-
   Utils.checkHost(host, "Expected hostname")
 
   val masterMetricsSystem = MetricsSystem.createMetricsSystem("master")
@@ -441,14 +439,6 @@ private[spark] class Master(host: String, port: Int, webUiPort: Int) extends Act
     idToApp(app.id) = app
     actorToApp(app.driver) = app
     addressToApp(appAddress) = app
-    if (firstApp == None) {
-      firstApp = Some(app)
-    }
-    // TODO: What is firstApp?? Can we remove it?
-    val workersAlive = workers.filter(_.state == WorkerState.ALIVE).toArray
-    if (workersAlive.size > 0 && !workersAlive.exists(_.memoryFree >= app.desc.memoryPerSlave)) {
-      logWarning("Could not find any workers with enough memory for " + firstApp.get.id)
-    }
     waitingApps += app
   }
 

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

@@ -18,12 +18,12 @@
 package org.apache.spark.deploy.master
 
 import scala.collection.JavaConversions._
-import scala.concurrent.ops._
 
-import org.apache.spark.Logging
 import org.apache.zookeeper._
-import org.apache.zookeeper.data.Stat
 import org.apache.zookeeper.Watcher.Event.KeeperState
+import org.apache.zookeeper.data.Stat
+
+import org.apache.spark.Logging
 
 /**
  * Provides a Scala-side interface to the standard ZooKeeper client, with the addition of retry
@@ -33,7 +33,7 @@ import org.apache.zookeeper.Watcher.Event.KeeperState
  * informed via zkDown().
  *
  * Additionally, all commands sent to ZooKeeper will be retried until they either fail too many
- * times or a semantic exception is thrown (e.g.., "node already exists").
+ * times or a semantic exception is thrown (e.g., "node already exists").
  */
 private[spark] class SparkZooKeeperSession(zkWatcher: SparkZooKeeperWatcher) extends Logging {
   val ZK_URL = System.getProperty("spark.deploy.zookeeper.url", "")
@@ -103,6 +103,7 @@ private[spark] class SparkZooKeeperSession(zkWatcher: SparkZooKeeperWatcher) ext
           connectToZooKeeper()
         case KeeperState.Disconnected =>
           logWarning("ZooKeeper disconnected, will retry...")
+        case s => // Do nothing
       }
     }
   }
@@ -179,7 +180,7 @@ private[spark] class SparkZooKeeperSession(zkWatcher: SparkZooKeeperWatcher) ext
     } catch {
       case e: KeeperException.NoNodeException => throw e
       case e: KeeperException.NodeExistsException => throw e
-      case e if n > 0 =>
+      case e: Exception if n > 0 =>
         logError("ZooKeeper exception, " + n + " more retries...", e)
         Thread.sleep(RETRY_WAIT_MILLIS)
         retry(fn, n-1)

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

@@ -21,8 +21,8 @@ import akka.actor.ActorRef
 import org.apache.zookeeper._
 import org.apache.zookeeper.Watcher.Event.EventType
 
-import org.apache.spark.deploy.master.MasterMessages._
 import org.apache.spark.Logging
+import org.apache.spark.deploy.master.MasterMessages._
 
 private[spark] class ZooKeeperLeaderElectionAgent(val masterActor: ActorRef, masterUrl: String)
   extends LeaderElectionAgent with SparkZooKeeperWatcher with Logging  {
@@ -105,7 +105,7 @@ private[spark] class ZooKeeperLeaderElectionAgent(val masterActor: ActorRef, mas
         // We found a different master file pointing to this process.
         // This can happen in the following two cases:
         // (1) The master process was restarted on the same node.
-        // (2) The ZK server died between creating the node and returning the name of the node.
+        // (2) The ZK server died between creating the file and returning the name of the file.
         //     For this case, we will end up creating a second file, and MUST explicitly delete the
         //     first one, since our ZK session is still open.
         // Note that this deletion will cause a NodeDeleted event to be fired so we check again for