2 files changed, 17 insertions, 1 deletions
diff --git a/yarn/src/main/scala/org/apache/spark/deploy/yarn/Client.scala b/yarn/src/main/scala/org/apache/spark/deploy/yarn/Client.scala
index a2c4bc2f54..8c53c24a79 100644
--- a/yarn/src/main/scala/org/apache/spark/deploy/yarn/Client.scala
+++ b/yarn/src/main/scala/org/apache/spark/deploy/yarn/Client.scala
@@ -86,7 +86,11 @@ private[spark] class Client(
   private val fireAndForget = isClusterMode &&
     !sparkConf.getBoolean("spark.yarn.submit.waitAppCompletion", true)
 
-  def stop(): Unit = yarnClient.stop()
+  def stop(): Unit = {
+    yarnClient.stop()
+    // Unset YARN mode system env variable, to allow switching between cluster types.
+    System.clearProperty("SPARK_YARN_MODE")
+  }
 
   /**
    * Submit an application running our ApplicationMaster to the ResourceManager.
diff --git a/yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnSparkHadoopUtilSuite.scala b/yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnSparkHadoopUtilSuite.scala
index 49bee0866d..e1c67db765 100644
--- a/yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnSparkHadoopUtilSuite.scala
+++ b/yarn/src/test/scala/org/apache/spark/deploy/yarn/YarnSparkHadoopUtilSuite.scala
@@ -30,6 +30,7 @@ import org.scalatest.Matchers
 import org.apache.hadoop.yarn.api.records.ApplicationAccessType
 
 import org.apache.spark.{Logging, SecurityManager, SparkConf, SparkException, SparkFunSuite}
+import org.apache.spark.deploy.SparkHadoopUtil
 import org.apache.spark.util.Utils
 
 
@@ -233,4 +234,15 @@ class YarnSparkHadoopUtilSuite extends SparkFunSuite with Matchers with Logging
       }
     assert(caught.getMessage === "Can't get Master Kerberos principal for use as renewer")
   }
+
+  test("check different hadoop utils based on env variable") {
+    try {
+      System.setProperty("SPARK_YARN_MODE", "true")
+      assert(SparkHadoopUtil.get.getClass === classOf[YarnSparkHadoopUtil])
+      System.setProperty("SPARK_YARN_MODE", "false")
+      assert(SparkHadoopUtil.get.getClass === classOf[SparkHadoopUtil])
+    } finally {
+      System.clearProperty("SPARK_YARN_MODE")
+    }
+  }
 }