[WIP] SPARK-1676: Cache Hadoop UGIs by default to prevent FileSystem leak

Move the doAs in Executor higher up so that we only have 1 ugi and aren't leaking filesystems.
Fix spark on yarn to work when the cluster is running as user "yarn" but the clients are launched as the user and want to read/write to hdfs as the user.

Note this hasn't been fully tested yet.  Need to test in standalone mode.

Putting this up for people to look at and possibly test.  I don't have access to a mesos cluster.

This is alternative to https://github.com/apache/spark/pull/607

Author: Thomas Graves <tgraves@apache.org>

Closes #621 from tgravescs/SPARK-1676 and squashes the following commits:

244d55a [Thomas Graves] fix line length
44163d4 [Thomas Graves] Rework
9398853 [Thomas Graves] change to have doAs in executor higher up.

4 files changed, 48 insertions, 31 deletions

diff --git a/core/src/main/scala/org/apache/spark/deploy/SparkHadoopUtil.scala b/core/src/main/scala/org/apache/spark/deploy/SparkHadoopUtil.scala
index 498fcc520a..e2df1b8954 100644
--- a/core/src/main/scala/org/apache/spark/deploy/SparkHadoopUtil.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/SparkHadoopUtil.scala
@@ -24,25 +24,36 @@ import org.apache.hadoop.mapred.JobConf
 import org.apache.hadoop.security.Credentials
 import org.apache.hadoop.security.UserGroupInformation
 
-import org.apache.spark.{SparkContext, SparkException}
+import org.apache.spark.{Logging, SparkContext, SparkException}
 
 import scala.collection.JavaConversions._
 
 /**
  * Contains util methods to interact with Hadoop from Spark.
  */
-class SparkHadoopUtil {
+class SparkHadoopUtil extends Logging {
   val conf: Configuration = newConfiguration()
   UserGroupInformation.setConfiguration(conf)
 
-  def runAsUser(user: String)(func: () => Unit) {
+  /**
+   * Runs the given function with a Hadoop UserGroupInformation as a thread local variable
+   * (distributed to child threads), used for authenticating HDFS and YARN calls.
+   *
+   * IMPORTANT NOTE: If this function is going to be called repeated in the same process
+   * you need to look https://issues.apache.org/jira/browse/HDFS-3545 and possibly
+   * do a FileSystem.closeAllForUGI in order to avoid leaking Filesystems
+   */
+  def runAsSparkUser(func: () => Unit) {
+    val user = Option(System.getenv("SPARK_USER")).getOrElse(SparkContext.SPARK_UNKNOWN_USER)
     if (user != SparkContext.SPARK_UNKNOWN_USER) {
+      logDebug("running as user: " + user)
       val ugi = UserGroupInformation.createRemoteUser(user)
       transferCredentials(UserGroupInformation.getCurrentUser(), ugi)
       ugi.doAs(new PrivilegedExceptionAction[Unit] {
         def run: Unit = func()
       })
     } else {
+      logDebug("running as SPARK_UNKNOWN_USER")
       func()
     }
   }
diff --git a/core/src/main/scala/org/apache/spark/executor/CoarseGrainedExecutorBackend.scala b/core/src/main/scala/org/apache/spark/executor/CoarseGrainedExecutorBackend.scala
index 9ac7365f47..e912ae8a5d 100644
--- a/core/src/main/scala/org/apache/spark/executor/CoarseGrainedExecutorBackend.scala
+++ b/core/src/main/scala/org/apache/spark/executor/CoarseGrainedExecutorBackend.scala
@@ -22,8 +22,9 @@ import java.nio.ByteBuffer
 import akka.actor._
 import akka.remote._
 
-import org.apache.spark.{SecurityManager, SparkConf, Logging}
+import org.apache.spark.{Logging, SecurityManager, SparkConf}
 import org.apache.spark.TaskState.TaskState
+import org.apache.spark.deploy.SparkHadoopUtil
 import org.apache.spark.deploy.worker.WorkerWatcher
 import org.apache.spark.scheduler.cluster.CoarseGrainedClusterMessages._
 import org.apache.spark.util.{AkkaUtils, Utils}
@@ -94,25 +95,30 @@ private[spark] class CoarseGrainedExecutorBackend(
 
 private[spark] object CoarseGrainedExecutorBackend {
   def run(driverUrl: String, executorId: String, hostname: String, cores: Int,
-          workerUrl: Option[String]) {
-    // Debug code
-    Utils.checkHost(hostname)
-
-    val conf = new SparkConf
-    // Create a new ActorSystem to run the backend, because we can't create a SparkEnv / Executor
-    // before getting started with all our system properties, etc
-    val (actorSystem, boundPort) = AkkaUtils.createActorSystem("sparkExecutor", hostname, 0,
-      indestructible = true, conf = conf, new SecurityManager(conf))
-    // set it
-    val sparkHostPort = hostname + ":" + boundPort
-    actorSystem.actorOf(
-      Props(classOf[CoarseGrainedExecutorBackend], driverUrl, executorId,
-        sparkHostPort, cores),
-      name = "Executor")
-    workerUrl.foreach{ url =>
-      actorSystem.actorOf(Props(classOf[WorkerWatcher], url), name = "WorkerWatcher")
+    workerUrl: Option[String]) {
+
+    SparkHadoopUtil.get.runAsSparkUser { () =>
+        // Debug code
+        Utils.checkHost(hostname)
+
+        val conf = new SparkConf
+        // Create a new ActorSystem to run the backend, because we can't create a
+        // SparkEnv / Executor before getting started with all our system properties, etc
+        val (actorSystem, boundPort) = AkkaUtils.createActorSystem("sparkExecutor", hostname, 0,
+          indestructible = true, conf = conf, new SecurityManager(conf))
+        // set it
+        val sparkHostPort = hostname + ":" + boundPort
+        actorSystem.actorOf(
+          Props(classOf[CoarseGrainedExecutorBackend], driverUrl, executorId,
+            sparkHostPort, cores),
+          name = "Executor")
+        workerUrl.foreach {
+          url =>
+            actorSystem.actorOf(Props(classOf[WorkerWatcher], url), name = "WorkerWatcher")
+        }
+        actorSystem.awaitTermination()
+
     }
-    actorSystem.awaitTermination()
   }
 
   def main(args: Array[String]) {
diff --git a/core/src/main/scala/org/apache/spark/executor/Executor.scala b/core/src/main/scala/org/apache/spark/executor/Executor.scala
index 272bcda5f8..98e7e0be81 100644
--- a/core/src/main/scala/org/apache/spark/executor/Executor.scala
+++ b/core/src/main/scala/org/apache/spark/executor/Executor.scala
@@ -128,8 +128,6 @@ private[spark] class Executor(
   // Maintains the list of running tasks.
   private val runningTasks = new ConcurrentHashMap[Long, TaskRunner]
 
-  val sparkUser = Option(System.getenv("SPARK_USER")).getOrElse(SparkContext.SPARK_UNKNOWN_USER)
-
   def launchTask(context: ExecutorBackend, taskId: Long, serializedTask: ByteBuffer) {
     val tr = new TaskRunner(context, taskId, serializedTask)
     runningTasks.put(taskId, tr)
@@ -172,7 +170,7 @@ private[spark] class Executor(
       }
     }
 
-    override def run(): Unit = SparkHadoopUtil.get.runAsUser(sparkUser) { () =>
+    override def run() {
       val startTime = System.currentTimeMillis()
       SparkEnv.set(env)
       Thread.currentThread.setContextClassLoader(replClassLoader)
diff --git a/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala b/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala
index 64e24506e8..9b56f711e0 100644
--- a/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala
+++ b/core/src/main/scala/org/apache/spark/executor/MesosExecutorBackend.scala
@@ -23,10 +23,10 @@ import com.google.protobuf.ByteString
 import org.apache.mesos.{Executor => MesosExecutor, ExecutorDriver, MesosExecutorDriver, MesosNativeLibrary}
 import org.apache.mesos.Protos.{TaskStatus => MesosTaskStatus, _}
 
-import org.apache.spark.Logging
-import org.apache.spark.TaskState
+import org.apache.spark.{Logging, TaskState}
 import org.apache.spark.TaskState.TaskState
 import org.apache.spark.util.Utils
+import org.apache.spark.deploy.SparkHadoopUtil
 
 private[spark] class MesosExecutorBackend
   extends MesosExecutor
@@ -95,9 +95,11 @@ private[spark] class MesosExecutorBackend
  */
 private[spark] object MesosExecutorBackend {
   def main(args: Array[String]) {
-    MesosNativeLibrary.load()
-    // Create a new Executor and start it running
-    val runner = new MesosExecutorBackend()
-    new MesosExecutorDriver(runner).run()
+    SparkHadoopUtil.get.runAsSparkUser { () =>
+        MesosNativeLibrary.load()
+        // Create a new Executor and start it running
+        val runner = new MesosExecutorBackend()
+        new MesosExecutorDriver(runner).run()
+    }
   }
 }