org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory#getPreviousDir

Source File: NNUpgradeUtil.java From hadoop with Apache License 2.0

6 votes

/**
 * Return true if this storage dir can roll back to the previous storage
 * state, false otherwise. The NN will refuse to run the rollback operation
 * unless at least one JM or fsimage storage directory can roll back.
 * 
 * @param storage the storage info for the current state
 * @param prevStorage the storage info for the previous (unupgraded) state
 * @param targetLayoutVersion the layout version we intend to roll back to
 * @return true if this JM can roll back, false otherwise.
 * @throws IOException in the event of error
 */
static boolean canRollBack(StorageDirectory sd, StorageInfo storage,
    StorageInfo prevStorage, int targetLayoutVersion) throws IOException {
  File prevDir = sd.getPreviousDir();
  if (!prevDir.exists()) {  // use current directory then
    LOG.info("Storage directory " + sd.getRoot()
             + " does not contain previous fs state.");
    // read and verify consistency with other directories
    storage.readProperties(sd);
    return false;
  }

  // read and verify consistency of the prev dir
  prevStorage.readPreviousVersionProperties(sd);

  if (prevStorage.getLayoutVersion() != targetLayoutVersion) {
    throw new IOException(
      "Cannot rollback to storage version " +
      prevStorage.getLayoutVersion() +
      " using this version of the NameNode, which uses storage version " +
      targetLayoutVersion + ". " +
      "Please use the previous version of HDFS to perform the rollback.");
  }
  
  return true;
}

Source File: NNUpgradeUtil.java From hadoop with Apache License 2.0

6 votes

/**
 * Finalize the upgrade. The previous dir, if any, will be renamed and
 * removed. After this is completed, rollback is no longer allowed.
 * 
 * @param sd the storage directory to finalize
 * @throws IOException in the event of error
 */
static void doFinalize(StorageDirectory sd) throws IOException {
  File prevDir = sd.getPreviousDir();
  if (!prevDir.exists()) { // already discarded
    LOG.info("Directory " + prevDir + " does not exist.");
    LOG.info("Finalize upgrade for " + sd.getRoot()+ " is not required.");
    return;
  }
  LOG.info("Finalizing upgrade of storage directory " + sd.getRoot());
  Preconditions.checkState(sd.getCurrentDir().exists(),
      "Current directory must exist.");
  final File tmpDir = sd.getFinalizedTmp();
  // rename previous to tmp and remove
  NNStorage.rename(prevDir, tmpDir);
  NNStorage.deleteDir(tmpDir);
  LOG.info("Finalize upgrade for " + sd.getRoot()+ " is complete.");
}

Source File: NNUpgradeUtil.java From hadoop with Apache License 2.0

6 votes

/**
 * 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);
  }
}

Source File: NNUpgradeUtil.java From hadoop with Apache License 2.0

6 votes

/**
 * 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;
  }
}

Source File: NNUpgradeUtil.java From hadoop with Apache License 2.0

6 votes

/**
 * Perform rollback of the storage dir to the previous state. The existing
 * current dir is removed, and the previous dir is renamed to current.
 * 
 * @param sd the storage directory to roll back.
 * @throws IOException in the event of error
 */
static void doRollBack(StorageDirectory sd)
    throws IOException {
  File prevDir = sd.getPreviousDir();
  if (!prevDir.exists()) {
    return;
  }

  File tmpDir = sd.getRemovedTmp();
  Preconditions.checkState(!tmpDir.exists(),
      "removed.tmp directory must not exist for rollback."
          + "Consider restarting for recovery.");
  // rename current to tmp
  File curDir = sd.getCurrentDir();
  Preconditions.checkState(curDir.exists(),
      "Current directory must exist for rollback.");

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

  // delete tmp dir
  NNStorage.deleteDir(tmpDir);
  LOG.info("Rollback of " + sd.getRoot() + " is complete.");
}