HDFS-9515. NPE when MiniDFSCluster#shutdown is invoked on uninitialized reference. (Contributed by Wei-Chiu Chuang)

2015-12-17 13:43:27 -08:00 · 2015-12-17 13:43:27 -08:00 · c0733db768
parent a40ff6d4fb
commit c0733db768
137 changed files with 320 additions and 68 deletions
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@ -1645,6 +1645,9 @@ Release 2.8.0 - UNRELEASED
    HDFS-9570. Minor typos, grammar, and case sensitivity cleanup in
    HdfsPermissionsGuide.md's (Travis Campbell via aw)

+    HDFS-9515. NPE when MiniDFSCluster#shutdown is invoked on uninitialized
+    reference. (Wei-Chiu Chuang via Arpit Agarwal)
+
 Release 2.7.3 - UNRELEASED

  INCOMPATIBLE CHANGES
--- a/hadoop-hdfs-project/hadoop-hdfs/src/contrib/bkjournal/src/test/java/org/apache/hadoop/contrib/bkjournal/TestBootstrapStandbyWithBKJM.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/contrib/bkjournal/src/test/java/org/apache/hadoop/contrib/bkjournal/TestBootstrapStandbyWithBKJM.java
@ -63,6 +63,7 @@ public class TestBootstrapStandbyWithBKJM {
  public void teardown() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestRefreshCallQueue.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/TestRefreshCallQueue.java
@ -86,6 +86,7 @@ public class TestRefreshCallQueue {
  public void tearDown() throws Exception {
    if(cluster!=null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestAclCLI.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestAclCLI.java
@ -49,9 +49,11 @@ public class TestAclCLI extends CLITestHelperDFS {
    super.tearDown();
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestCacheAdminCLI.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestCacheAdminCLI.java
@ -76,9 +76,11 @@ public class TestCacheAdminCLI extends CLITestHelper {
  public void tearDown() throws Exception {
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (dfsCluster != null) {
      dfsCluster.shutdown();
+      dfsCluster = null;
    }
    Thread.sleep(2000);
    super.tearDown();
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestCryptoAdminCLI.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestCryptoAdminCLI.java
@ -86,9 +86,11 @@ public class TestCryptoAdminCLI extends CLITestHelperDFS {
  public void tearDown() throws Exception {
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (dfsCluster != null) {
      dfsCluster.shutdown();
+      dfsCluster = null;
    }
    Thread.sleep(2000);
    super.tearDown();
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestDeleteCLI.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestDeleteCLI.java
@ -58,9 +58,11 @@ public class TestDeleteCLI extends CLITestHelperDFS {
  public void tearDown() throws Exception {
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (dfsCluster != null) {
      dfsCluster.shutdown();
+      dfsCluster = null;
    }
    Thread.sleep(2000);
    super.tearDown();
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestHDFSCLI.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestHDFSCLI.java
@ -77,9 +77,11 @@ public class TestHDFSCLI extends CLITestHelperDFS {
  public void tearDown() throws Exception {
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (dfsCluster != null) {
      dfsCluster.shutdown();
+      dfsCluster = null;
    }
    Thread.sleep(2000);
    super.tearDown();
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestXAttrCLI.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cli/TestXAttrCLI.java
@ -67,9 +67,11 @@ public class TestXAttrCLI  extends CLITestHelperDFS {
  public void tearDown() throws Exception {
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (dfsCluster != null) {
      dfsCluster.shutdown();
+      dfsCluster = null;
    }
    Thread.sleep(2000);
    super.tearDown();
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/TestFcHdfsCreateMkdir.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/TestFcHdfsCreateMkdir.java
@ -58,7 +58,9 @@ public class TestFcHdfsCreateMkdir extends
      
  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();   
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }
  
  @Override
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/TestFcHdfsPermission.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/TestFcHdfsPermission.java
@ -66,7 +66,9 @@ public class TestFcHdfsPermission extends FileContextPermissionBase {
      
  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();   
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }
  
  @Override
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/TestFcHdfsSetUMask.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/TestFcHdfsSetUMask.java
@ -96,7 +96,9 @@ public class TestFcHdfsSetUMask {

  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();   
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }
  
  {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/TestSymlinkHdfs.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/TestSymlinkHdfs.java
@ -98,7 +98,9 @@ abstract public class TestSymlinkHdfs extends SymlinkBaseTest {

  @AfterClass
  public static void afterClassTeardown() throws Exception {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  @Test(timeout=10000)
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/contract/hdfs/HDFSContract.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/contract/hdfs/HDFSContract.java
@ -62,6 +62,7 @@ public class HDFSContract extends AbstractFSContract {
  public static void destroyCluster() throws IOException {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/shell/TestHdfsTextCommand.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/shell/TestHdfsTextCommand.java
@ -60,9 +60,11 @@ public class TestHdfsTextCommand {
    public void tearDown() throws IOException{
    if(fs != null){
      fs.close();
+      fs = null;
    }
    if(cluster != null){
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFileSystemHdfs.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFileSystemHdfs.java
@ -88,7 +88,9 @@ public class TestViewFileSystemHdfs extends ViewFileSystemBaseTest {
      
  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();   
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  @Override
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFileSystemWithAcls.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFileSystemWithAcls.java
@ -76,7 +76,9 @@ public class TestViewFileSystemWithAcls {

  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  @Before
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFileSystemWithXAttrs.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFileSystemWithXAttrs.java
@ -71,7 +71,9 @@ public class TestViewFileSystemWithXAttrs {

  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  @Before
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsAtHdfsRoot.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsAtHdfsRoot.java
@ -64,7 +64,9 @@ public class TestViewFsAtHdfsRoot extends ViewFsBaseTest {
      
  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();   
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  @Override
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsHdfs.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsHdfs.java
@ -64,7 +64,9 @@ public class TestViewFsHdfs extends ViewFsBaseTest {
      
  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();   
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  @Override
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsWithAcls.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsWithAcls.java
@ -76,7 +76,9 @@ public class TestViewFsWithAcls {

  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  @Before
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsWithXAttrs.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsWithXAttrs.java
@ -70,7 +70,9 @@ public class TestViewFsWithXAttrs {

  @AfterClass
  public static void ClusterShutdownAtEnd() throws Exception {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  @Before
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/FileAppendTest4.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/FileAppendTest4.java
@ -68,7 +68,9 @@ public class FileAppendTest4 {

  @AfterClass
  public static void tearDown() {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }
  
  /**
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestAbandonBlock.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestAbandonBlock.java
@ -56,8 +56,14 @@ public class TestAbandonBlock {

  @After
  public void tearDown() throws Exception {
-    fs.close();
-    cluster.shutdown();
+    if (fs != null) {
+      fs.close();
+      fs = null;
+    }
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  @Test
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestBlocksScheduledCounter.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestBlocksScheduledCounter.java
@ -43,9 +43,11 @@ public class TestBlocksScheduledCounter {
  public void tearDown() throws IOException {
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if(cluster!=null){
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestClientReportBadBlock.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestClientReportBadBlock.java
@ -82,8 +82,14 @@ public class TestClientReportBadBlock {

  @After
  public void shutDownCluster() throws IOException {
-    dfs.close();
-    cluster.shutdown();
+    if (dfs != null) {
+      dfs.close();
+      dfs = null;
+    }
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  /*
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientExcludedNodes.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientExcludedNodes.java
@ -54,6 +54,7 @@ public class TestDFSClientExcludedNodes {
  public void tearDown() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientFailover.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientFailover.java
@ -88,6 +88,7 @@ public class TestDFSClientFailover {
  public void tearDownCluster() throws IOException {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientSocketSize.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientSocketSize.java
@ -82,6 +82,7 @@ public class TestDFSClientSocketSize {
    if (cluster != null) {
      LOG.info("Shutting down MiniDFSCluster.");
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSFinalize.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSFinalize.java
@ -188,7 +188,10 @@ public class TestDFSFinalize {
  @After
  public void tearDown() throws Exception {
    LOG.info("Shutting down MiniDFSCluster");
-    if (cluster != null) cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }
  
  public static void main(String[] args) throws Exception {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSOutputStream.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSOutputStream.java
@ -150,6 +150,8 @@ public class TestDFSOutputStream {

  @AfterClass
  public static void tearDown() {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }
 }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSPermission.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSPermission.java
@ -123,6 +123,7 @@ public class TestDFSPermission {
  public void tearDown() throws IOException {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSRollback.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSRollback.java
@ -346,7 +346,10 @@ public class TestDFSRollback {
  @After
  public void tearDown() throws Exception {
    LOG.info("Shutting down MiniDFSCluster");
-    if (cluster != null) cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }
  
  public static void main(String[] args) throws Exception {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStartupVersions.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStartupVersions.java
@ -282,7 +282,10 @@ public class TestDFSStartupVersions {
  @After
  public void tearDown() throws Exception {
    LOG.info("Shutting down MiniDFSCluster");
-    if (cluster != null) cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }
  
  public static void main(String[] args) throws Exception {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStorageStateRecovery.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSStorageStateRecovery.java
@ -452,6 +452,9 @@ public class TestDFSStorageStateRecovery {
  @After
  public void tearDown() throws Exception {
    LOG.info("Shutting down MiniDFSCluster");
-    if (cluster != null) cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }
 }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDataTransferKeepalive.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDataTransferKeepalive.java
@ -69,7 +69,10 @@ public class TestDataTransferKeepalive {
  
  @After
  public void teardown() {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }
  
  /**
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDecommission.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDecommission.java
@ -126,6 +126,7 @@ public class TestDecommission {
    cleanupFile(localFileSys, dir);
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestEncryptionZones.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestEncryptionZones.java
@ -170,6 +170,7 @@ public class TestEncryptionZones {
  public void teardown() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
    EncryptionFaultInjector.instance = new EncryptionFaultInjector();
  }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestEncryptionZonesWithHA.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestEncryptionZonesWithHA.java
@ -87,6 +87,7 @@ public class TestEncryptionZonesWithHA {
  public void shutdownCluster() throws IOException {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileConcurrentReader.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileConcurrentReader.java
@ -84,8 +84,10 @@ public class TestFileConcurrentReader {

  @After
  public void tearDown() throws Exception {
-    cluster.shutdown();
-    cluster = null;
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  private void init(Configuration conf) throws IOException {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileStatus.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestFileStatus.java
@ -82,8 +82,12 @@ public class TestFileStatus {
  
  @AfterClass
  public static void testTearDown() throws Exception {
-    fs.close();
-    cluster.shutdown();
+    if (fs != null) {
+      fs.close();
+    }
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  private static void writeFile(FileSystem fileSys, Path name, int repl,
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestGetFileChecksum.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestGetFileChecksum.java
@ -52,6 +52,7 @@ public class TestGetFileChecksum {
  public void tearDown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestHDFSFileSystemContract.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestHDFSFileSystemContract.java
@ -45,8 +45,10 @@ public class TestHDFSFileSystemContract extends FileSystemContractBaseTest {
  @Override
  protected void tearDown() throws Exception {
    super.tearDown();
-    cluster.shutdown();
-    cluster = null;
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  @Override
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestHdfsAdmin.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestHdfsAdmin.java
@ -47,6 +47,7 @@ public class TestHdfsAdmin {
  public void shutDownCluster() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery.java
@ -57,6 +57,7 @@ public class TestLeaseRecovery {
  public void shutdown() throws IOException {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery2.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestLeaseRecovery2.java
@ -101,8 +101,10 @@ public class TestLeaseRecovery2 {
   */
  @AfterClass
  public static void tearDown() throws IOException {
-    IOUtils.closeStream(dfs);
-    if (cluster != null) {cluster.shutdown();}
+    if (cluster != null) {
+      IOUtils.closeStream(dfs);
+      cluster.shutdown();
+    }
  }

  /**
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestListFilesInDFS.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestListFilesInDFS.java
@ -46,8 +46,10 @@ public class TestListFilesInDFS extends TestListFiles {
  
  @AfterClass
  public static void testShutdown() throws Exception {
-    fs.close();
-    cluster.shutdown();
+    if (cluster != null) {
+      fs.close();
+      cluster.shutdown();
+    }
  }
  
  protected static Path getTestDir() {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestListFilesInFileContext.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestListFilesInFileContext.java
@ -83,7 +83,9 @@ public class TestListFilesInFileContext {
  
  @AfterClass
  public static void testShutdown() throws Exception {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  /** Test when input path is a file */
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestPipelines.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestPipelines.java
@ -65,11 +65,14 @@ public class TestPipelines {

  @After
  public void shutDownCluster() throws IOException {
-    if (fs != null)
+    if (fs != null) {
      fs.close();
+      fs = null;
+    }
    if (cluster != null) {
      cluster.shutdownDataNodes();
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestReservedRawPaths.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestReservedRawPaths.java
@ -91,6 +91,7 @@ public class TestReservedRawPaths {
  public void teardown() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestSafeMode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestSafeMode.java
@ -90,9 +90,11 @@ public class TestSafeMode {
  public void tearDown() throws IOException {
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestWriteRead.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestWriteRead.java
@ -86,7 +86,10 @@ public class TestWriteRead {

  @After
  public void shutdown() {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  // Equivalence of @Before for cluster mode testing.
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/protocol/datatransfer/sasl/TestSaslDataTransfer.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/protocol/datatransfer/sasl/TestSaslDataTransfer.java
@ -67,6 +67,7 @@ public class TestSaslDataTransfer extends SaslDataTransferTestCase {
    IOUtils.cleanup(null, fs);
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/qjournal/TestSecureNNWithQJM.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/qjournal/TestSecureNNWithQJM.java
@ -154,9 +154,11 @@ public class TestSecureNNWithQJM {
    IOUtils.cleanup(null, fs);
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
    if (mjc != null) {
      mjc.shutdown();
+      mjc = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/qjournal/client/TestQuorumJournalManager.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/qjournal/client/TestQuorumJournalManager.java
@ -114,6 +114,7 @@ public class TestQuorumJournalManager {
    
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/qjournal/server/TestJournalNodeMXBean.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/qjournal/server/TestJournalNodeMXBean.java
@ -61,6 +61,7 @@ public class TestJournalNodeMXBean {
  public void cleanup() throws IOException {
    if (jCluster != null) {
      jCluster.shutdown();
+      jCluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/security/TestDelegationToken.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/security/TestDelegationToken.java
@ -86,6 +86,7 @@ public class TestDelegationToken {
  public void tearDown() throws Exception {
    if(cluster!=null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockStatsMXBean.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestBlockStatsMXBean.java
@ -67,6 +67,7 @@ public class TestBlockStatsMXBean {
  public void tearDown() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestComputeInvalidateWork.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestComputeInvalidateWork.java
@ -70,6 +70,7 @@ public class TestComputeInvalidateWork {
  public void teardown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestPendingInvalidateBlock.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/blockmanagement/TestPendingInvalidateBlock.java
@ -74,6 +74,7 @@ public class TestPendingInvalidateBlock {
  public void tearDown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/BlockReportTestBase.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/BlockReportTestBase.java
@ -115,10 +115,12 @@ public abstract class BlockReportTestBase {
  public void shutDownCluster() throws IOException {
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (cluster != null) {
      cluster.shutdownDataNodes();
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeExit.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeExit.java
@ -59,8 +59,10 @@ public class TestDataNodeExit {

  @After
  public void tearDown() throws Exception {
-    if (cluster != null)
+    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
+    }
  }
  
  private void stopBPServiceThreads(int numStopThreads, DataNode dn)
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeVolumeFailure.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeVolumeFailure.java
@ -116,12 +116,15 @@ public class TestDataNodeVolumeFailure {
  public void tearDown() throws Exception {
    if(data_fail != null) {
      FileUtil.setWritable(data_fail, true);
+      data_fail = null;
    }
    if(failedDir != null) {
      FileUtil.setWritable(failedDir, true);
+      failedDir = null;
    }
    if(cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeVolumeFailureReporting.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeVolumeFailureReporting.java
@ -89,6 +89,7 @@ public class TestDataNodeVolumeFailureReporting {
    IOUtils.cleanup(LOG, fs);
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeVolumeFailureToleration.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeVolumeFailureToleration.java
@ -78,6 +78,7 @@ public class TestDataNodeVolumeFailureToleration {
  public void tearDown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDiskError.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDiskError.java
@ -71,7 +71,10 @@ public class TestDiskError {

  @After
  public void tearDown() throws Exception {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  /**
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestFsDatasetCache.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestFsDatasetCache.java
@ -149,9 +149,11 @@ public class TestFsDatasetCache {
    DFSTestUtil.verifyExpectedCacheUsage(0, 0, fsd);
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
    // Restore the original CacheManipulator
    NativeIO.POSIX.setCacheManipulator(prevCacheManipulator);
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestIncrementalBrVariations.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestIncrementalBrVariations.java
@ -101,10 +101,13 @@ public class TestIncrementalBrVariations {

  @After
  public void shutDownCluster() throws IOException {
-    client.close();
-    fs.close();
-    cluster.shutdownDataNodes();
-    cluster.shutdown();
+    if (cluster != null) {
+      client.close();
+      fs.close();
+      cluster.shutdownDataNodes();
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  /**
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestAclConfigFlag.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestAclConfigFlag.java
@ -58,6 +58,7 @@ public class TestAclConfigFlag {
    IOUtils.cleanup(null, fs);
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestAddBlock.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestAddBlock.java
@ -60,6 +60,7 @@ public class TestAddBlock {
  public void tearDown() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestAddBlockRetry.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestAddBlockRetry.java
@ -66,6 +66,7 @@ public class TestAddBlockRetry {
  public void tearDown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestAuditLogs.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestAuditLogs.java
@ -140,8 +140,14 @@ public class TestAuditLogs {
  @After
  public void teardownCluster() throws Exception {
    util.cleanup(fs, "/srcdat");
-    fs.close();
-    cluster.shutdown();
+    if (fs != null) {
+      fs.close();
+      fs = null;
+    }
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  /** test that allowed operation puts proper entry in audit log */
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestBackupNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestBackupNode.java
@ -477,7 +477,9 @@ public class TestBackupNode {
      assertTrue(e.getLocalizedMessage(), false);
    } finally {
      fileSys.close();
-      cluster.shutdown();
+      if (cluster != null) {
+        cluster.shutdown();
+      }
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestBlockPlacementPolicyRackFaultTolerant.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestBlockPlacementPolicyRackFaultTolerant.java
@ -83,6 +83,7 @@ public class TestBlockPlacementPolicyRackFaultTolerant {
  public void teardown() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestCacheDirectives.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestCacheDirectives.java
@ -159,6 +159,7 @@ public class TestCacheDirectives {
    waitForCachedBlocks(namenode, 0, 0, "teardown");
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
    // Restore the original CacheManipulator
    NativeIO.POSIX.setCacheManipulator(prevCacheManipulator);
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestCommitBlockWithInvalidGenStamp.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestCommitBlockWithInvalidGenStamp.java
@ -58,6 +58,7 @@ public class TestCommitBlockWithInvalidGenStamp {
  public void tearDown() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDeadDatanode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDeadDatanode.java
@ -62,7 +62,10 @@ public class TestDeadDatanode {

  @After
  public void cleanup() {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  /**
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDefaultBlockPlacementPolicy.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDefaultBlockPlacementPolicy.java
@ -71,6 +71,7 @@ public class TestDefaultBlockPlacementPolicy {
  public void teardown() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDiskspaceQuotaUpdate.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestDiskspaceQuotaUpdate.java
@ -71,6 +71,7 @@ public class TestDiskspaceQuotaUpdate {
  public void tearDown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEditLogAutoroll.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEditLogAutoroll.java
@ -97,9 +97,11 @@ public class TestEditLogAutoroll {
  public void tearDown() throws Exception {
    if (fs != null) {
      fs.close();
+      fs = null;
    }
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEditLogJournalFailures.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEditLogJournalFailures.java
@ -70,11 +70,14 @@ public class TestEditLogJournalFailures {
  
  @After
  public void shutDownMiniCluster() throws IOException {
-    if (fs != null)
+    if (fs != null) {
      fs.close();
+      fs = null;
+    }
    if (cluster != null) {
      try {
        cluster.shutdown();
+        cluster = null;
      } catch (ExitException ee) {
        // Ignore ExitExceptions as the tests may result in the
        // NameNode doing an immediate shutdown.
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSDirectory.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSDirectory.java
@ -109,6 +109,7 @@ public class TestFSDirectory {
  public void tearDown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSImageWithAcl.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSImageWithAcl.java
@ -55,7 +55,9 @@ public class TestFSImageWithAcl {

  @AfterClass
  public static void tearDown() {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  private void testAcl(boolean persistNamespace) throws IOException {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSImageWithSnapshot.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSImageWithSnapshot.java
@ -89,6 +89,7 @@ public class TestFSImageWithSnapshot {
  public void tearDown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSImageWithXAttr.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSImageWithXAttr.java
@ -62,7 +62,9 @@ public class TestFSImageWithXAttr {

  @AfterClass
  public static void tearDown() {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+    }
  }

  private void testXAttr(boolean persistNamespace) throws IOException {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFileTruncate.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFileTruncate.java
@ -109,8 +109,14 @@ public class TestFileTruncate {

  @After
  public void tearDown() throws IOException {
-    if(fs != null)      fs.close();
-    if(cluster != null) cluster.shutdown();
+    if(fs != null) {
+      fs.close();
+      fs = null;
+    }
+    if(cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }

  /**
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestHDFSConcat.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestHDFSConcat.java
@ -84,10 +84,12 @@ public class TestHDFSConcat {
  public void shutDownCluster() throws IOException {
    if(dfs != null) {
      dfs.close();
+      dfs = null;
    }
    if(cluster != null) {
      cluster.shutdownDataNodes();
      cluster.shutdown();
+      cluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestINodeAttributeProvider.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestINodeAttributeProvider.java
@ -186,6 +186,7 @@ public class TestINodeAttributeProvider {
    CALLED.clear();
    if (miniDFS != null) {
      miniDFS.shutdown();
+      miniDFS = null;
    }
    Assert.assertTrue(CALLED.contains("stop"));
  }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestMalformedURLs.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestMalformedURLs.java
@ -54,6 +54,7 @@ public class TestMalformedURLs {
  public void tearDown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }
 }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestMetadataVersionOutput.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestMetadataVersionOutput.java
@ -45,6 +45,7 @@ public class TestMetadataVersionOutput {
  public void tearDown() throws Exception {
    if (dfsCluster != null) {
      dfsCluster.shutdown();
+      dfsCluster = null;
    }
    Thread.sleep(2000);
  }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeMetadataConsistency.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeMetadataConsistency.java
@ -63,6 +63,7 @@ public class TestNameNodeMetadataConsistency {
  public void cleanup() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeRetryCacheMetrics.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeRetryCacheMetrics.java
@ -80,6 +80,7 @@ public class TestNameNodeRetryCacheMetrics {
  public void cleanup() throws IOException {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeRpcServerMethods.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNameNodeRpcServerMethods.java
@ -55,8 +55,10 @@ public class TestNameNodeRpcServerMethods {
   */
  @After
  public void cleanup() throws IOException {
-    if (cluster != null)
+    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
+    }
  }

  @Test
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNamenodeRetryCache.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestNamenodeRetryCache.java
@ -105,7 +105,10 @@ public class TestNamenodeRetryCache {
   * @throws AccessControlException */
  @After
  public void cleanup() throws IOException {
-    cluster.shutdown();
+    if (cluster != null) {
+      cluster.shutdown();
+      cluster = null;
+    }
  }
  
  /** Set the current Server RPC call */
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestQuotaByStorageType.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestQuotaByStorageType.java
@ -74,6 +74,7 @@ public class TestQuotaByStorageType {
  public void tearDown() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestXAttrConfigFlag.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestXAttrConfigFlag.java
@ -51,6 +51,7 @@ public class TestXAttrConfigFlag {
    IOUtils.cleanup(null, fs);
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestBootstrapStandby.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestBootstrapStandby.java
@ -80,6 +80,7 @@ public class TestBootstrapStandby {
  public void shutdownCluster() {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestBootstrapStandbyWithQJM.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestBootstrapStandbyWithQJM.java
@ -79,9 +79,11 @@ public class TestBootstrapStandbyWithQJM {
  public void cleanup() throws IOException {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
    if (jCluster != null) {
      jCluster.shutdown();
+      jCluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestDNFencing.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestDNFencing.java
@ -118,6 +118,7 @@ public class TestDNFencing {
      banner("Shutting down cluster. NN2 metadata:");
      doMetasave(nn2);
      cluster.shutdown();
+      cluster = null;
    }
  }
  
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestDelegationTokensWithHA.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestDelegationTokensWithHA.java
@ -107,6 +107,7 @@ public class TestDelegationTokensWithHA {
  public void shutdownCluster() throws IOException {
    if (cluster != null) {
      cluster.shutdown();
+      cluster = null;
    }
  }

--- a/Show More
+++ b/Show More