HDFS-13556. TestNestedEncryptionZones does not shut down cluster. Contributed by Anbang Hu.

(cherry picked from commit a97a2042f210e9db97646baad6f56064d672f447)

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNestedEncryptionZones.java

@@ -35,6 +35,7 @@ import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.ToolRunner;
 import org.apache.log4j.Level;
 import org.apache.log4j.Logger;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -111,6 +112,14 @@ public class TestNestedEncryptionZones {
     DFSTestUtil.createKey(NESTED_EZ_KEY, cluster, conf);
   }
 
+  @After
+  public void tearDown() throws Exception {
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
+  }
+
   @Test(timeout = 60000)
   public void testNestedEncryptionZones() throws Exception {
     initTopEZDirAndNestedEZDir(new Path(rootDir, "topEZ"));