Java StorageDirectory.getPreviousTmp方法代码示例

import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory; //导入方法依赖的package包/类
/**
 * Perform any steps that must succeed across all storage dirs/JournalManagers
 * involved in an upgrade before proceeding onto the actual upgrade stage. If
 * a call to any JM's or local storage dir's doPreUpgrade method fails, then
 * doUpgrade will not be called for any JM. The existing current dir is
 * renamed to previous.tmp, and then a new, empty current dir is created.
 *
 * @param conf configuration for creating {@link EditLogFileOutputStream}
 * @param sd the storage directory to perform the pre-upgrade procedure.
 * @throws IOException in the event of error
 */
static void doPreUpgrade(Configuration conf, StorageDirectory sd)
    throws IOException {
  LOG.info("Starting upgrade of storage directory " + sd.getRoot());

  // rename current to tmp
  renameCurToTmp(sd);

  final File curDir = sd.getCurrentDir();
  final File tmpDir = sd.getPreviousTmp();
  List<String> fileNameList = IOUtils.listDirectory(tmpDir, new FilenameFilter() {
    @Override
    public boolean accept(File dir, String name) {
      return dir.equals(tmpDir)
          && name.startsWith(NNStorage.NameNodeFile.EDITS.getName());
    }
  });

  for (String s : fileNameList) {
    File prevFile = new File(tmpDir, s);
    File newFile = new File(curDir, prevFile.getName());
    Files.createLink(newFile.toPath(), prevFile.toPath());
  }
}
 

import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory; //导入方法依赖的package包/类
/**
 * Rename the existing current dir to previous.tmp, and create a new empty
 * current dir.
 */
public static void renameCurToTmp(StorageDirectory sd) throws IOException {
  File curDir = sd.getCurrentDir();
  File prevDir = sd.getPreviousDir();
  final File tmpDir = sd.getPreviousTmp();

  Preconditions.checkState(curDir.exists(),
      "Current directory must exist for preupgrade.");
  Preconditions.checkState(!prevDir.exists(),
      "Previous directory must not exist for preupgrade.");
  Preconditions.checkState(!tmpDir.exists(),
      "Previous.tmp directory must not exist for preupgrade."
          + "Consider restarting for recovery.");

  // rename current to tmp
  NNStorage.rename(curDir, tmpDir);

  if (!curDir.mkdir()) {
    throw new IOException("Cannot create directory " + curDir);
  }
}
 

import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory; //导入方法依赖的package包/类
/**
 * Perform the upgrade of the storage dir to the given storage info. The new
 * storage info is written into the current directory, and the previous.tmp
 * directory is renamed to previous.
 * 
 * @param sd the storage directory to upgrade
 * @param storage info about the new upgraded versions.
 * @throws IOException in the event of error
 */
public static void doUpgrade(StorageDirectory sd, Storage storage)
    throws IOException {
  LOG.info("Performing upgrade of storage directory " + sd.getRoot());
  try {
    // Write the version file, since saveFsImage only makes the
    // fsimage_<txid>, and the directory is otherwise empty.
    storage.writeProperties(sd);

    File prevDir = sd.getPreviousDir();
    File tmpDir = sd.getPreviousTmp();
    Preconditions.checkState(!prevDir.exists(),
        "previous directory must not exist for upgrade.");
    Preconditions.checkState(tmpDir.exists(),
        "previous.tmp directory must exist for upgrade.");

    // rename tmp to previous
    NNStorage.rename(tmpDir, prevDir);
  } catch (IOException ioe) {
    LOG.error("Unable to rename temp to previous for " + sd.getRoot(), ioe);
    throw ioe;
  }
}