Question

我需要遵循哪些步骤才能将新 NameNode数据目录（dfs.name.dir，dfs.namenode.name.dir）正确添加到现有生产集群？我已将新路径添加到hdfs-site.xml文件中以逗号分隔的列表中，但是当我尝试启动namenode时，我收到以下错误：

目录/ data / nfs / dfs / nn处于不一致状态：存储目录不存在或无法访问。

在我的情况下，我已经有两个目录并且正常工作。（/ data / 1 / dfs / nn，/ data / 2 / dfs / nn）当我添加新目录时，我无法启动namenode。删除新路径后，它就会正常启动。我对新目录的fstab如下所示：

backup-server：/ hadoop_nn / data / nfs / dfs nfs tcp，soft，intr，timeo = 10，retrans = 10 1 2

在上面的挂载点中，我创建了一个名为nn的文件夹。该文件夹与nn文件夹中的其他两个现有位置具有相同的所有权和权限。

drwx ------ 2 hdfs hadoop 64 Jan 22 16:30 nn

我是否需要手动复制/复制现有namenode目录中的所有文件，或者namenode服务在启动时是否自动执行？

Answer 1

我相信我可能刚刚回答了我自己的问题。我最终将其中一个现有namenode目录的全部内容复制到新的NFS namenode目录，然后我就可以启动namenode了。（注意我在复制之前停止了namenode以避免出现问题）

cp -rp /data/1/dfs/nn /data/nfs/dfs/nn

我想我的假设是namenode会自动将现有元数据复制到新目录，这是不正确的。

Answer 2

在Cloudera CDH 4.5.0中，只有当以下函数（来自Storage.java，第418行）返回NON_EXISTENT时才会发生该错误。在每种情况下都会显示一条警告，其中包含更多详细信息，请查找来自org.apache.hadoop.hdfs.server.common.Storage的日志行。

简而言之，名称节点似乎认为它不存在，不是目录，不可写或以其他方式抛出SecurityException。

/**
 * Check consistency of the storage directory
 * 
 * @param startOpt a startup option.
 *  
 * @return state {@link StorageState} of the storage directory 
 * @throws InconsistentFSStateException if directory state is not 
 * consistent and cannot be recovered.
 * @throws IOException
 */
public StorageState analyzeStorage(StartupOption startOpt, Storage storage)
    throws IOException {
  assert root != null : "root is null";
  String rootPath = root.getCanonicalPath();
  try { // check that storage exists
    if (!root.exists()) {
      // storage directory does not exist
      if (startOpt != StartupOption.FORMAT) {
        LOG.warn("Storage directory " + rootPath + " does not exist");
        return StorageState.NON_EXISTENT;
      }
      LOG.info(rootPath + " does not exist. Creating ...");
      if (!root.mkdirs())
        throw new IOException("Cannot create directory " + rootPath);
    }
    // or is inaccessible
    if (!root.isDirectory()) {
      LOG.warn(rootPath + "is not a directory");
      return StorageState.NON_EXISTENT;
    }
    if (!root.canWrite()) {
      LOG.warn("Cannot access storage directory " + rootPath);
      return StorageState.NON_EXISTENT;
    }
  } catch(SecurityException ex) {
    LOG.warn("Cannot access storage directory " + rootPath, ex);
    return StorageState.NON_EXISTENT;
  }

  this.lock(); // lock storage if it exists

  if (startOpt == HdfsServerConstants.StartupOption.FORMAT)
    return StorageState.NOT_FORMATTED;

  if (startOpt != HdfsServerConstants.StartupOption.IMPORT) {
    storage.checkOldLayoutStorage(this);
  }

  // check whether current directory is valid
  File versionFile = getVersionFile();
  boolean hasCurrent = versionFile.exists();

  // check which directories exist
  boolean hasPrevious = getPreviousDir().exists();
  boolean hasPreviousTmp = getPreviousTmp().exists();
  boolean hasRemovedTmp = getRemovedTmp().exists();
  boolean hasFinalizedTmp = getFinalizedTmp().exists();
  boolean hasCheckpointTmp = getLastCheckpointTmp().exists();

  if (!(hasPreviousTmp || hasRemovedTmp
      || hasFinalizedTmp || hasCheckpointTmp)) {
    // no temp dirs - no recovery
    if (hasCurrent)
      return StorageState.NORMAL;
    if (hasPrevious)
      throw new InconsistentFSStateException(root,
                          "version file in current directory is missing.");
    return StorageState.NOT_FORMATTED;
  }

  if ((hasPreviousTmp?1:0) + (hasRemovedTmp?1:0)
      + (hasFinalizedTmp?1:0) + (hasCheckpointTmp?1:0) > 1)
    // more than one temp dirs
    throw new InconsistentFSStateException(root,
                                           "too many temporary directories.");

  // # of temp dirs == 1 should either recover or complete a transition
  if (hasCheckpointTmp) {
    return hasCurrent ? StorageState.COMPLETE_CHECKPOINT
                      : StorageState.RECOVER_CHECKPOINT;
  }

  if (hasFinalizedTmp) {
    if (hasPrevious)
      throw new InconsistentFSStateException(root,
                                             STORAGE_DIR_PREVIOUS + " and " + STORAGE_TMP_FINALIZED
                                             + "cannot exist together.");
    return StorageState.COMPLETE_FINALIZE;
  }

  if (hasPreviousTmp) {
    if (hasPrevious)
      throw new InconsistentFSStateException(root,
                                             STORAGE_DIR_PREVIOUS + " and " + STORAGE_TMP_PREVIOUS
                                             + " cannot exist together.");
    if (hasCurrent)
      return StorageState.COMPLETE_UPGRADE;
    return StorageState.RECOVER_UPGRADE;
  }

  assert hasRemovedTmp : "hasRemovedTmp must be true";
  if (!(hasCurrent ^ hasPrevious))
    throw new InconsistentFSStateException(root,
                                           "one and only one directory " + STORAGE_DIR_CURRENT 
                                           + " or " + STORAGE_DIR_PREVIOUS 
                                           + " must be present when " + STORAGE_TMP_REMOVED
                                           + " exists.");
  if (hasCurrent)
    return StorageState.COMPLETE_ROLLBACK;
  return StorageState.RECOVER_ROLLBACK;
}

将新的namenode数据目录添加到现有集群

2 个答案: