import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * test
 */
public void printStorages(FSImage fs) {
  LOG.info("current storages and corresoponding sizes:");
  for (Iterator<StorageDirectory> it = fs.dirIterator(); it.hasNext();) {
    StorageDirectory sd = it.next();

    if (sd.getStorageDirType().isOfType(NameNodeDirType.IMAGE)) {
      File imf = FSImage.getImageFile(sd, NameNodeFile.IMAGE);
      LOG.info("  image file " + imf.getAbsolutePath() + "; len = "
          + imf.length());
    }
    if (sd.getStorageDirType().isOfType(NameNodeDirType.EDITS)) {
      File edf = FSImage.getImageFile(sd, NameNodeFile.EDITS);
      LOG.info("  edits file " + edf.getAbsolutePath() + "; len = "
          + edf.length());
    }
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * verify that edits log and fsimage are in different directories and of a correct size
 */
private void verifyDifferentDirs(FSImage img, long expectedImgSize, long expectedEditsSize) {
  StorageDirectory sd =null;
  for (Iterator<StorageDirectory> it = img.dirIterator(); it.hasNext();) {
    sd = it.next();

    if(sd.getStorageDirType().isOfType(NameNodeDirType.IMAGE)) {
      File imf = FSImage.getImageFile(sd, NameNodeFile.IMAGE);
      LOG.info("--image file " + imf.getAbsolutePath() + "; len = " + imf.length() + "; expected = " + expectedImgSize);
      assertEquals(expectedImgSize, imf.length());	
    } else if(sd.getStorageDirType().isOfType(NameNodeDirType.EDITS)) {
      File edf = FSImage.getImageFile(sd, NameNodeFile.EDITS);
      LOG.info("-- edits file " + edf.getAbsolutePath() + "; len = " + edf.length()  + "; expected = " + expectedEditsSize);
      assertEquals(expectedEditsSize, edf.length());	
    } else {
      fail("Image/Edits directories are not different");
    }
  }

}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * Merge image and edits, and verify consistency with the signature.
 */
private void doMerge(CheckpointSignature sig) throws IOException {
  getEditLog().open();
  StorageDirectory sdName = null;
  StorageDirectory sdEdits = null;
  Iterator<StorageDirectory> it = null;
  it = dirIterator(NameNodeDirType.IMAGE);
  if (it.hasNext())
    sdName = it.next();
  it = dirIterator(NameNodeDirType.EDITS);
  if (it.hasNext())
    sdEdits = it.next();
  if ((sdName == null) || (sdEdits == null))
    throw new IOException("Could not locate checkpoint directories");
  this.layoutVersion = -1; // to avoid assert in loadFSImage()
  loadFSImage(FSImage.getImageFile(sdName, NameNodeFile.IMAGE));
  loadFSEdits(sdEdits);
  sig.validateStorageInfo(this);
  saveNamespace(false);
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * Closes the current edit log and opens edits.new. 
 */
synchronized void rollEditLog() throws IOException {
  waitForSyncToFinish();
  Iterator<StorageDirectory> it = fsimage.dirIterator(NameNodeDirType.EDITS);
  if(!it.hasNext()) 
    return;
  //
  // If edits.new already exists in some directory, verify it
  // exists in all directories.
  //
  boolean alreadyExists = existsNew(it.next());
  while(it.hasNext()) {
    StorageDirectory sd = it.next();
    if(alreadyExists != existsNew(sd))
      throw new IOException(getEditNewFile(sd) 
            + "should " + (alreadyExists ? "" : "not ") + "exist.");
  }
  if(alreadyExists)
    return; // nothing to do, edits.new exists!

  // check if any of failed storage is now available and put it back
  fsimage.attemptRestoreRemovedStorage();

  divertFileStreams(
      Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.EDITS_NEW.getName());
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * test
 */
public void printStorages(FSImage fs) {
  LOG.info("current storages and corresoponding sizes:");
  for(Iterator<StorageDirectory> it = fs.dirIterator(); it.hasNext(); ) {
    StorageDirectory sd = it.next();
    
    if(sd.getStorageDirType().isOfType(NameNodeDirType.IMAGE)) {
      File imf = FSImage.getImageFile(sd, NameNodeFile.IMAGE);
      LOG.info("  image file " + imf.getAbsolutePath() + "; len = " + imf.length());  
    }
    if(sd.getStorageDirType().isOfType(NameNodeDirType.EDITS)) {
      File edf = FSImage.getImageFile(sd, NameNodeFile.EDITS);
      LOG.info("  edits file " + edf.getAbsolutePath() + "; len = " + edf.length()); 
    }
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * Test that a corrupted fstime file in a single storage directory does not
 * prevent the NN from starting up.
 */
@Test
public void testFsTimeFileCorrupt() throws IOException, InterruptedException {
  assertEquals(cluster.getNameDirs().size(), 2);
  // Get the first fstime file and truncate it.
  truncateStorageDirFile(cluster, NameNodeFile.TIME, 0);
  // Make sure we can start up despite the fact the fstime file is corrupted.
  cluster.restartNameNode();
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
private static void truncateStorageDirFile(MiniDFSCluster cluster,
    NameNodeFile f, int storageDirIndex) throws IOException {
  File currentDir = cluster.getNameNode().getFSImage()
      .getStorageDir(storageDirIndex).getCurrentDir();
  File nameNodeFile = new File(currentDir, f.getName());
  assertTrue(nameNodeFile.isFile());
  assertTrue(nameNodeFile.delete());
  assertTrue(nameNodeFile.createNewFile());
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
void runTest(EditFileModifier modifier) throws IOException {
  //set toleration length
  final Configuration conf = new Configuration();
  conf.setInt(DFSConfigKeys.DFS_NAMENODE_EDITS_TOLERATION_LENGTH_KEY, TOLERATION_LENGTH);

  final MiniDFSCluster cluster = new MiniDFSCluster(conf, 0, true, null);
  try {
    cluster.waitActive();

    //add a few transactions and then shutdown namenode.
    final FileSystem fs = cluster.getFileSystem();
    fs.mkdirs(new Path("/user/foo"));
    fs.mkdirs(new Path("/user/bar"));
    cluster.shutdownNameNode();

    //modify edit files
    for(File dir : FSNamesystem.getNamespaceEditsDirs(conf)) {
      final File editFile  = new File(new File(dir, "current"),
          NameNodeFile.EDITS.getName());
      assertTrue("Should exist: " + editFile, editFile.exists());

      modifier.modify(editFile);
    }

    try {
      //restart namenode.
      cluster.restartNameNode();
      
      //No exception: the modification must be tolerable.
      Assert.assertTrue(modifier.isTolerable());
    } catch (IOException e) {
      //Got an exception: the modification must be intolerable.
      LOG.info("Got an exception", e);
      Assert.assertFalse(modifier.isTolerable());
    }
  } finally {
    cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
private void corruptNameNodeFiles() throws IOException {
  // now corrupt/delete the directrory
  List<File> nameDirs = (List<File>)FSNamesystem.getNamespaceDirs(config);
  List<File> nameEditsDirs = (List<File>)FSNamesystem.getNamespaceEditsDirs(config);

  // get name dir and its length, then delete and recreate the directory
  File dir = nameDirs.get(0); // has only one
  this.fsimageLength = new File(new File(dir, "current"), 
      NameNodeFile.IMAGE.getName()).length();

  if(dir.exists() && !(FileUtil.fullyDelete(dir)))
    throw new IOException("Cannot remove directory: " + dir);

  LOG.info("--removed dir "+dir + ";len was ="+ this.fsimageLength);

  if (!dir.mkdirs())
    throw new IOException("Cannot create directory " + dir);

  dir = nameEditsDirs.get(0); //has only one

  this.editsLength = new File(new File(dir, "current"), 
      NameNodeFile.EDITS.getName()).length();

  if(dir.exists() && !(FileUtil.fullyDelete(dir)))
    throw new IOException("Cannot remove directory: " + dir);
  if (!dir.mkdirs())
    throw new IOException("Cannot create directory " + dir);

  LOG.info("--removed dir and recreated "+dir + ";len was ="+ this.editsLength);


}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
private void verifyEditLogs(FSNamesystem namesystem, FSImage fsimage)
  throws IOException {
  // Verify that we can read in all the transactions that we have written.
  // If there were any corruptions, it is likely that the reading in
  // of these transactions will throw an exception.
  for (Iterator<StorageDirectory> it = 
         fsimage.dirIterator(NameNodeDirType.EDITS); it.hasNext();) {
    File editFile = FSImage.getImageFile(it.next(), NameNodeFile.EDITS);
    System.out.println("Verifying file: " + editFile);
    int numEdits = new FSEditLogLoader(namesystem).loadFSEdits(
      new EditLogFileInputStream(editFile));
    System.out.println("Number of edits: " + numEdits);
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * read currentCheckpointTime directly from the file
 * @param currDir
 * @return the checkpoint time
 * @throws IOException
 */
long readCheckpointTime(File currDir) throws IOException {
  File timeFile = new File(currDir, NameNodeFile.TIME.getName()); 
  long timeStamp = 0L;
  if (timeFile.exists() && timeFile.canRead()) {
    DataInputStream in = new DataInputStream(new FileInputStream(timeFile));
    try {
      timeStamp = in.readLong();
    } finally {
      in.close();
    }
  }
  return timeStamp;
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
private void corruptNameNodeFiles() throws IOException {
  // now corrupt/delete the directrory
  List<URI> nameDirs = (List<URI>)FSNamesystem.getNamespaceDirs(config);
  List<URI> nameEditsDirs = (List<URI>)FSNamesystem.getNamespaceEditsDirs(config);

  // get name dir and its length, then delete and recreate the directory
  File dir = new File(nameDirs.get(0).getPath()); // has only one
  this.fsimageLength = new File(new File(dir, "current"), 
      NameNodeFile.IMAGE.getName()).length();

  if(dir.exists() && !(FileUtil.fullyDelete(dir)))
    throw new IOException("Cannot remove directory: " + dir);

  LOG.info("--removed dir "+dir + ";len was ="+ this.fsimageLength);

  if (!dir.mkdirs())
    throw new IOException("Cannot create directory " + dir);

  dir = new File( nameEditsDirs.get(0).getPath()); //has only one

  this.editsLength = new File(new File(dir, "current"), 
      NameNodeFile.EDITS.getName()).length();

  if(dir.exists() && !(FileUtil.fullyDelete(dir)))
    throw new IOException("Cannot remove directory: " + dir);
  if (!dir.mkdirs())
    throw new IOException("Cannot create directory " + dir);

  LOG.info("--removed dir and recreated "+dir + ";len was ="+ this.editsLength);


}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 *  check if files exist/not exist
 */
public void checkFiles(boolean valid) {
  //look at the valid storage
  File fsImg1 = new File(path1, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.IMAGE.getName());
  File fsImg2 = new File(path2, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.IMAGE.getName());
  File fsImg3 = new File(path3, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.IMAGE.getName());

  File fsEdits1 = new File(path1, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.EDITS.getName());
  File fsEdits2 = new File(path2, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.EDITS.getName());
  File fsEdits3 = new File(path3, Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.EDITS.getName());

  this.printStorages(cluster.getNameNode().getFSImage());
  
  LOG.info("++++ image files = "+fsImg1.getAbsolutePath() + "," + fsImg2.getAbsolutePath() + ","+ fsImg3.getAbsolutePath());
  LOG.info("++++ edits files = "+fsEdits1.getAbsolutePath() + "," + fsEdits2.getAbsolutePath() + ","+ fsEdits3.getAbsolutePath());
  LOG.info("checkFiles compares lengths: img1=" + fsImg1.length()  + ",img2=" + fsImg2.length()  + ",img3=" + fsImg3.length());
  LOG.info("checkFiles compares lengths: edits1=" + fsEdits1.length()  + ",edits2=" + fsEdits2.length()  + ",edits3=" + fsEdits3.length());
  
  if(valid) {
    assertTrue(fsImg1.exists());
    assertTrue(fsImg2.exists());
    assertFalse(fsImg3.exists());
    assertTrue(fsEdits1.exists());
    assertTrue(fsEdits2.exists());
    assertTrue(fsEdits3.exists());
    
   // should be the same
    assertTrue(fsImg1.length() == fsImg2.length());
    assertTrue(fsEdits1.length() == fsEdits2.length());
    assertTrue(fsEdits1.length() == fsEdits3.length());
  } else {
    // should be different
    assertTrue(fsEdits2.length() != fsEdits1.length());
    assertTrue(fsEdits2.length() != fsEdits3.length());
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
private void verifyEditLogs(FSImage fsimage)
  throws IOException {
  // Verify that we can read in all the transactions that we have written.
  // If there were any corruptions, it is likely that the reading in
  // of these transactions will throw an exception.
  for (Iterator<StorageDirectory> it = 
         fsimage.dirIterator(NameNodeDirType.EDITS); it.hasNext();) {
    File editFile = FSImage.getImageFile(it.next(), NameNodeFile.EDITS);
    System.out.println("Verifying file: " + editFile);
    int numEdits = FSEditLog.loadFSEdits(
      new FSEditLog.EditLogFileInputStream(editFile));
    System.out.println("Number of edits: " + numEdits);
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * Tests transaction logging in dfs.
 */
public void testEditLog() throws IOException {

  // start a cluster 
  Configuration conf = new Configuration();
  MiniDFSCluster cluster = null;
  FileSystem fileSys = null;

  try {
    cluster = new MiniDFSCluster(conf, NUM_DATA_NODES, true, null);
    cluster.waitActive();
    fileSys = cluster.getFileSystem();
    final FSNamesystem namesystem = cluster.getNameNode().getNamesystem();

    for (Iterator<File> it = cluster.getNameDirs().iterator(); it.hasNext(); ) {
      File dir = new File(it.next().getPath());
      System.out.println(dir);
    }
    
    FSImage fsimage = namesystem.getFSImage();
    FSEditLog editLog = fsimage.getEditLog();

    // set small size of flush buffer
    editLog.setBufferCapacity(2048);
    editLog.close();
    editLog.open();
    namesystem.getDelegationTokenSecretManager().startThreads();
  
    // Create threads and make them run transactions concurrently.
    Thread threadId[] = new Thread[NUM_THREADS];
    for (int i = 0; i < NUM_THREADS; i++) {
      Transactions trans = new Transactions(namesystem, NUM_TRANSACTIONS);
      threadId[i] = new Thread(trans, "TransactionThread-" + i);
      threadId[i].start();
    }

    // wait for all transactions to get over
    for (int i = 0; i < NUM_THREADS; i++) {
      try {
        threadId[i].join();
      } catch (InterruptedException e) {
        i--;      // retry 
      }
    } 
    
    editLog.close();

    // Verify that we can read in all the transactions that we have written.
    // If there were any corruptions, it is likely that the reading in
    // of these transactions will throw an exception.
    //
    namesystem.getDelegationTokenSecretManager().stopThreads();
    int numKeys = namesystem.getDelegationTokenSecretManager().getNumberOfKeys();
    for (Iterator<StorageDirectory> it = 
            fsimage.dirIterator(NameNodeDirType.EDITS); it.hasNext();) {
      File editFile = FSImage.getImageFile(it.next(), NameNodeFile.EDITS);
      System.out.println("Verifying file: " + editFile);
      int numEdits = FSEditLog.loadFSEdits(
          new EditLogFileInputStream(editFile), -1);
      assertTrue("Verification for " + editFile + " failed. " +
                 "Expected " + (NUM_THREADS * opsPerTrans * NUM_TRANSACTIONS + numKeys) + " transactions. "+
                 "Found " + numEdits + " transactions.",
                 numEdits == NUM_THREADS * opsPerTrans * NUM_TRANSACTIONS +numKeys);

    }
  } finally {
    if(fileSys != null) fileSys.close();
    if(cluster != null) cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * Simulate a secondary node failure to transfer image
 * back to the name-node.
 * Used to truncate primary fsimage file.
 */
void testSecondaryFailsToReturnImage(Configuration conf)
  throws IOException {
  System.out.println("Starting testSecondaryFailsToReturnImage");
  Path file1 = new Path("checkpointRI.dat");
  MiniDFSCluster cluster = new MiniDFSCluster(conf, numDatanodes, 
                                              false, null);
  cluster.waitActive();
  FileSystem fileSys = cluster.getFileSystem();
  FSImage image = cluster.getNameNode().getFSImage();
  try {
    assertTrue(!fileSys.exists(file1));
    StorageDirectory sd = null;
    for (Iterator<StorageDirectory> it = 
              image.dirIterator(NameNodeDirType.IMAGE); it.hasNext();)
       sd = it.next();
    assertTrue(sd != null);
    long fsimageLength = FSImage.getImageFile(sd, NameNodeFile.IMAGE).length();
    //
    // Make the checkpoint
    //
    SecondaryNameNode secondary = startSecondaryNameNode(conf);
    ErrorSimulator.setErrorSimulation(2);

    try {
      secondary.doCheckpoint();  // this should fail
      assertTrue(false);
    } catch (IOException e) {
      System.out.println("testSecondaryFailsToReturnImage: doCheckpoint() " +
          "failed predictably - " + e);
    }
    ErrorSimulator.clearErrorSimulation(2);

    // Verify that image file sizes did not change.
    for (Iterator<StorageDirectory> it = 
            image.dirIterator(NameNodeDirType.IMAGE); it.hasNext();) {
      assertTrue(FSImage.getImageFile(it.next(), 
                              NameNodeFile.IMAGE).length() == fsimageLength);
    }

    secondary.shutdown();
  } finally {
    fileSys.close();
    cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * check if files exist/not exist
 */
public void checkFiles(boolean valid) {
  // look at the valid storage
  File fsImg1 = new File(path1, Storage.STORAGE_DIR_CURRENT + "/"
      + NameNodeFile.IMAGE.getName());
  File fsImg2 = new File(path2, Storage.STORAGE_DIR_CURRENT + "/"
      + NameNodeFile.IMAGE.getName());
  File fsImg3 = new File(path3, Storage.STORAGE_DIR_CURRENT + "/"
      + NameNodeFile.IMAGE.getName());

  File fsEdits1 = new File(path1, Storage.STORAGE_DIR_CURRENT + "/"
      + NameNodeFile.EDITS.getName());
  File fsEdits2 = new File(path2, Storage.STORAGE_DIR_CURRENT + "/"
      + NameNodeFile.EDITS.getName());
  File fsEdits3 = new File(path3, Storage.STORAGE_DIR_CURRENT + "/"
      + NameNodeFile.EDITS.getName());
  
  this.printStorages(cluster.getNameNode().getFSImage());
  
  String md5_1 = null,md5_2 = null,md5_3 = null;
  try {
    md5_1 = getFileMD5(fsEdits1);
    md5_2 = getFileMD5(fsEdits2);
    md5_3 = getFileMD5(fsEdits3);
  } catch (Exception e) {
    System.err.println("md 5 calculation failed:" + e.getLocalizedMessage());
  }
  
  LOG.info("++++ image files = " + fsImg1.getAbsolutePath() + ","
      + fsImg2.getAbsolutePath() + "," + fsImg3.getAbsolutePath());
  LOG.info("++++ edits files = " + fsEdits1.getAbsolutePath() + ","
      + fsEdits2.getAbsolutePath() + "," + fsEdits3.getAbsolutePath());
  LOG.info("checkFiles compares lengths: img1=" + fsImg1.length() + ",img2="
      + fsImg2.length() + ",img3=" + fsImg3.length());
  LOG.info("checkFiles compares lengths: edits1=" + fsEdits1.length()
      + ",edits2=" + fsEdits2.length() + ",edits3=" + fsEdits3.length());

  if (valid) {
    // should be the same
    assertTrue(fsImg1.length() == fsImg2.length());
    assertTrue(0 == fsImg3.length()); // shouldn't be created
    assertTrue(fsEdits1.length() == fsEdits2.length());
    assertTrue(md5_1.equals(md5_2));
    assertTrue(md5_1.equals(md5_3));
  } else {
    // should be different
    assertFalse(md5_1.equals(md5_2));
    assertFalse(md5_1.equals(md5_2));
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * Tests transaction logging in dfs.
 */
public void testEditLog() throws IOException {

  // start a cluster 

  Collection<File> namedirs = null;
  Collection<File> editsdirs = null;
  Configuration conf = new Configuration();
  MiniDFSCluster cluster = new MiniDFSCluster(0, conf, numDatanodes, 
                                              true, true, null, null);
  cluster.waitActive();
  FileSystem fileSys = cluster.getFileSystem();
  int numdirs = 0;

  try {
    namedirs = cluster.getNameDirs();
    editsdirs = cluster.getNameEditsDirs();
  } finally {
    fileSys.close();
    cluster.shutdown();
  }

  for (Iterator it = namedirs.iterator(); it.hasNext(); ) {
    File dir = (File)it.next();
    System.out.println(dir);
    numdirs++;
  }

  FSImage fsimage = new FSImage(namedirs, editsdirs);
  FSEditLog editLog = fsimage.getEditLog();

  // set small size of flush buffer
  editLog.setBufferCapacity(2048);
  editLog.close();
  editLog.open();

  // Create threads and make them run transactions concurrently.
  Thread threadId[] = new Thread[numThreads];
  for (int i = 0; i < numThreads; i++) {
    Transactions trans = new Transactions(editLog, numberTransactions);
    threadId[i] = new Thread(trans, "TransactionThread-" + i);
    threadId[i].start();
  }

  // wait for all transactions to get over
  for (int i = 0; i < numThreads; i++) {
    try {
      threadId[i].join();
    } catch (InterruptedException e) {
      i--;      // retry 
    }
  } 
  
  editLog.close();

  // Verify that we can read in all the transactions that we have written.
  // If there were any corruptions, it is likely that the reading in
  // of these transactions will throw an exception.
  //
  for (Iterator<StorageDirectory> it = 
          fsimage.dirIterator(NameNodeDirType.EDITS); it.hasNext();) {
    File editFile = FSImage.getImageFile(it.next(), NameNodeFile.EDITS);
    System.out.println("Verifying file: " + editFile);
    int numEdits = FSEditLog.loadFSEdits(new EditLogFileInputStream(editFile), -1);
    int numLeases = FSNamesystem.getFSNamesystem().leaseManager.countLease();
    System.out.println("Number of outstanding leases " + numLeases);
    assertEquals(0, numLeases);
    assertTrue("Verification for " + editFile + " failed. " +
               "Expected " + (numThreads * 2 * numberTransactions) + " transactions. "+
               "Found " + numEdits + " transactions.",
               numEdits == numThreads * 2 * numberTransactions);

  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * secnn-7
 * secondary node copies fsimage and edits into correct separate directories.
 * @throws IOException
 */
public void testSNNStartup() throws IOException{
  //setUpConfig();
  LOG.info("--starting SecondNN startup test");
  // different name dirs
  config.set("dfs.name.dir", new File(hdfsDir, "name").getPath());
  config.set("dfs.name.edits.dir", new File(hdfsDir, "name").getPath());
  // same checkpoint dirs
  config.set("fs.checkpoint.edits.dir", new File(hdfsDir, "chkpt_edits").getPath());
  config.set("fs.checkpoint.dir", new File(hdfsDir, "chkpt").getPath());

  LOG.info("--starting NN ");
  MiniDFSCluster cluster = null;
  SecondaryNameNode sn = null;
  NameNode nn = null;
  try {
    cluster = new MiniDFSCluster(0, config, 1, true, false, false,  null, null, null, null);
    cluster.waitActive();
    nn = cluster.getNameNode();
    assertNotNull(nn);

    // start secondary node
    LOG.info("--starting SecondNN");
    sn = new SecondaryNameNode(config);
    assertNotNull(sn);

    LOG.info("--doing checkpoint");
    sn.doCheckpoint();  // this shouldn't fail
    LOG.info("--done checkpoint");



    // now verify that image and edits are created in the different directories
    FSImage image = nn.getFSImage();
    StorageDirectory sd = image.getStorageDir(0); //only one
    assertEquals(sd.getStorageDirType(), NameNodeDirType.IMAGE_AND_EDITS);
    File imf = FSImage.getImageFile(sd, NameNodeFile.IMAGE);
    File edf = FSImage.getImageFile(sd, NameNodeFile.EDITS);
    LOG.info("--image file " + imf.getAbsolutePath() + "; len = " + imf.length());
    LOG.info("--edits file " + edf.getAbsolutePath() + "; len = " + edf.length());

    FSImage chkpImage = sn.getFSImage();
    verifyDifferentDirs(chkpImage, imf.length(), edf.length());

  } catch (IOException e) {
    fail(StringUtils.stringifyException(e));
    System.err.println("checkpoint failed");
    throw e;
  } finally {
    if(sn!=null)
      sn.shutdown();
    if(cluster!=null)
      cluster.shutdown();
  }
}
 

import org.apache.hadoop.hdfs.server.namenode.FSImage.NameNodeFile; //导入依赖的package包/类
/**
 * Removes the old edit log and renames edits.new to edits.
 * Reopens the edits file.
 */
synchronized void purgeEditLog() throws IOException {
  waitForSyncToFinish();
  revertFileStreams(
      Storage.STORAGE_DIR_CURRENT + "/" + NameNodeFile.EDITS_NEW.getName());
}