Java StorageDirectory.analyzeStorage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
/**
 * Analyze backup storage directories for consistency.<br>
 * Recover from incomplete checkpoints if required.<br>
 * Read VERSION and fstime files if exist.<br>
 * Do not load image or edits.
 *
 * @throws IOException if the node should shutdown.
 */
void recoverCreateRead() throws IOException {
  for (Iterator<StorageDirectory> it = storage.dirIterator(); it.hasNext();) {
    StorageDirectory sd = it.next();
    StorageState curState;
    try {
      curState = sd.analyzeStorage(HdfsServerConstants.StartupOption.REGULAR, storage);
      // sd is locked but not opened
      switch(curState) {
      case NON_EXISTENT:
        // fail if any of the configured storage dirs are inaccessible
        throw new InconsistentFSStateException(sd.getRoot(),
              "checkpoint directory does not exist or is not accessible.");
      case NOT_FORMATTED:
        // for backup node all directories may be unformatted initially
        LOG.info("Storage directory " + sd.getRoot() + " is not formatted.");
        LOG.info("Formatting ...");
        sd.clearDirectory(); // create empty current
        break;
      case NORMAL:
        break;
      default:  // recovery is possible
        sd.doRecover(curState);
      }
      if(curState != StorageState.NOT_FORMATTED) {
        // read and verify consistency with other directories
        storage.readProperties(sd);
      }
    } catch(IOException ioe) {
      sd.unlock();
      throw ioe;
    }
  }
}
 

import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory; //导入方法依赖的package包/类
/**
 * For each storage directory, performs recovery of incomplete transitions
 * (eg. upgrade, rollback, checkpoint) and inserts the directory's storage
 * state into the dataDirStates map.
 * @param dataDirStates output of storage directory states
 * @return true if there is at least one valid formatted storage directory
 */
public static boolean recoverStorageDirs(StartupOption startOpt,
    NNStorage storage, Map<StorageDirectory, StorageState> dataDirStates)
    throws IOException {
  boolean isFormatted = false;
  // This loop needs to be over all storage dirs, even shared dirs, to make
  // sure that we properly examine their state, but we make sure we don't
  // mutate the shared dir below in the actual loop.
  for (Iterator<StorageDirectory> it = 
                    storage.dirIterator(); it.hasNext();) {
    StorageDirectory sd = it.next();
    StorageState curState;
    if (startOpt == StartupOption.METADATAVERSION) {
      /* All we need is the layout version. */
      storage.readProperties(sd);
      return true;
    }

    try {
      curState = sd.analyzeStorage(startOpt, storage);
      // sd is locked but not opened
      switch(curState) {
      case NON_EXISTENT:
        // name-node fails if any of the configured storage dirs are missing
        throw new InconsistentFSStateException(sd.getRoot(),
                    "storage directory does not exist or is not accessible.");
      case NOT_FORMATTED:
        break;
      case NORMAL:
        break;
      default:  // recovery is possible
        sd.doRecover(curState);
      }
      if (curState != StorageState.NOT_FORMATTED 
          && startOpt != StartupOption.ROLLBACK) {
        // read and verify consistency with other directories
        storage.readProperties(sd, startOpt);
        isFormatted = true;
      }
      if (startOpt == StartupOption.IMPORT && isFormatted)
        // import of a checkpoint is allowed only into empty image directories
        throw new IOException("Cannot import image from a checkpoint. " 
            + " NameNode already contains an image in " + sd.getRoot());
    } catch (IOException ioe) {
      sd.unlock();
      throw ioe;
    }
    dataDirStates.put(sd,curState);
  }
  return isFormatted;
}
 

import org.apache.hadoop.hdfs.server.common.Storage.StorageDirectory; //导入方法依赖的package包/类
/**
 * Analyze checkpoint directories.
 * Create directories if they do not exist.
 * Recover from an unsuccessful checkpoint if necessary.
 *
 * @throws IOException
 */
void recoverCreate(boolean format) throws IOException {
  storage.attemptRestoreRemovedStorage();
  storage.unlockAll();

  for (Iterator<StorageDirectory> it = 
               storage.dirIterator(); it.hasNext();) {
    StorageDirectory sd = it.next();
    boolean isAccessible = true;
    try { // create directories if don't exist yet
      if(!sd.getRoot().mkdirs()) {
        // do nothing, directory is already created
      }
    } catch(SecurityException se) {
      isAccessible = false;
    }
    if(!isAccessible)
      throw new InconsistentFSStateException(sd.getRoot(),
          "cannot access checkpoint directory.");
    
    if (format) {
      // Don't confirm, since this is just the secondary namenode.
      LOG.info("Formatting storage directory " + sd);
      sd.clearDirectory();
    }
    
    StorageState curState;
    try {
      curState = sd.analyzeStorage(HdfsServerConstants.StartupOption.REGULAR, storage);
      // sd is locked but not opened
      switch(curState) {
      case NON_EXISTENT:
        // fail if any of the configured checkpoint dirs are inaccessible 
        throw new InconsistentFSStateException(sd.getRoot(),
              "checkpoint directory does not exist or is not accessible.");
      case NOT_FORMATTED:
        break;  // it's ok since initially there is no current and VERSION
      case NORMAL:
        // Read the VERSION file. This verifies that:
        // (a) the VERSION file for each of the directories is the same,
        // and (b) when we connect to a NN, we can verify that the remote
        // node matches the same namespace that we ran on previously.
        storage.readProperties(sd);
        break;
      default:  // recovery is possible
        sd.doRecover(curState);
      }
    } catch (IOException ioe) {
      sd.unlock();
      throw ioe;
    }
  }
}