/** Removes the table from hbase:meta and archives the HDFS files. */
  protected void removeTableData(final List<HRegionInfo> regions)
      throws IOException, CoordinatedStateException {
    try {
      // 1. Remove regions from META
      LOG.debug("Deleting regions from META");
      MetaTableAccessor.deleteRegions(this.server.getConnection(), regions);

      // -----------------------------------------------------------------------
      // NOTE: At this point we still have data on disk, but nothing in hbase:meta
      //       if the rename below fails, hbck will report an inconsistency.
      // -----------------------------------------------------------------------

      // 2. Move the table in /hbase/.tmp
      MasterFileSystem mfs = this.masterServices.getMasterFileSystem();
      Path tempTableDir = mfs.moveTableToTemp(tableName);

      // 3. Archive regions from FS (temp directory)
      FileSystem fs = mfs.getFileSystem();
      for (HRegionInfo hri : regions) {
        LOG.debug("Archiving region " + hri.getRegionNameAsString() + " from FS");
        HFileArchiver.archiveRegion(
            fs,
            mfs.getRootDir(),
            tempTableDir,
            HRegion.getRegionDir(tempTableDir, hri.getEncodedName()));
      }

      // 4. Delete table directory from FS (temp directory)
      if (!fs.delete(tempTableDir, true)) {
        LOG.error("Couldn't delete " + tempTableDir);
      }

      LOG.debug("Table '" + tableName + "' archived!");
    } finally {
      cleanupTableState();
    }
  }
  /**
   * Called at startup, to verify if snapshot operation is supported, and to avoid starting the
   * master if there're snapshots present but the cleaners needed are missing. Otherwise we can end
   * up with snapshot data loss.
   *
   * @param conf The {@link Configuration} object to use
   * @param mfs The MasterFileSystem to use
   * @throws IOException in case of file-system operation failure
   * @throws UnsupportedOperationException in case cleaners are missing and there're snapshot in the
   *     system
   */
  private void checkSnapshotSupport(final Configuration conf, final MasterFileSystem mfs)
      throws IOException, UnsupportedOperationException {
    // Verify if snapshot is disabled by the user
    String enabled = conf.get(HBASE_SNAPSHOT_ENABLED);
    boolean snapshotEnabled = conf.getBoolean(HBASE_SNAPSHOT_ENABLED, false);
    boolean userDisabled = (enabled != null && enabled.trim().length() > 0 && !snapshotEnabled);

    // Extract cleaners from conf
    Set<String> hfileCleaners = new HashSet<String>();
    String[] cleaners = conf.getStrings(HFileCleaner.MASTER_HFILE_CLEANER_PLUGINS);
    if (cleaners != null) Collections.addAll(hfileCleaners, cleaners);

    Set<String> logCleaners = new HashSet<String>();
    cleaners = conf.getStrings(HConstants.HBASE_MASTER_LOGCLEANER_PLUGINS);
    if (cleaners != null) Collections.addAll(logCleaners, cleaners);

    // check if an older version of snapshot directory was present
    Path oldSnapshotDir = new Path(mfs.getRootDir(), HConstants.OLD_SNAPSHOT_DIR_NAME);
    FileSystem fs = mfs.getFileSystem();
    List<SnapshotDescription> ss = getCompletedSnapshots(new Path(rootDir, oldSnapshotDir));
    if (ss != null && !ss.isEmpty()) {
      LOG.error("Snapshots from an earlier release were found under: " + oldSnapshotDir);
      LOG.error("Please rename the directory as " + HConstants.SNAPSHOT_DIR_NAME);
    }

    // If the user has enabled the snapshot, we force the cleaners to be present
    // otherwise we still need to check if cleaners are enabled or not and verify
    // that there're no snapshot in the .snapshot folder.
    if (snapshotEnabled) {
      // Inject snapshot cleaners, if snapshot.enable is true
      hfileCleaners.add(SnapshotHFileCleaner.class.getName());
      hfileCleaners.add(HFileLinkCleaner.class.getName());

      // Set cleaners conf
      conf.setStrings(
          HFileCleaner.MASTER_HFILE_CLEANER_PLUGINS,
          hfileCleaners.toArray(new String[hfileCleaners.size()]));
      conf.setStrings(
          HConstants.HBASE_MASTER_LOGCLEANER_PLUGINS,
          logCleaners.toArray(new String[logCleaners.size()]));
    } else {
      // Verify if cleaners are present
      snapshotEnabled =
          hfileCleaners.contains(SnapshotHFileCleaner.class.getName())
              && hfileCleaners.contains(HFileLinkCleaner.class.getName());

      // Warn if the cleaners are enabled but the snapshot.enabled property is false/not set.
      if (snapshotEnabled) {
        LOG.warn(
            "Snapshot log and hfile cleaners are present in the configuration, "
                + "but the '"
                + HBASE_SNAPSHOT_ENABLED
                + "' property "
                + (userDisabled ? "is set to 'false'." : "is not set."));
      }
    }

    // Mark snapshot feature as enabled if cleaners are present and user has not disabled it.
    this.isSnapshotSupported = snapshotEnabled && !userDisabled;

    // If cleaners are not enabled, verify that there're no snapshot in the .snapshot folder
    // otherwise we end up with snapshot data loss.
    if (!snapshotEnabled) {
      LOG.info("Snapshot feature is not enabled, missing log and hfile cleaners.");
      Path snapshotDir = SnapshotDescriptionUtils.getSnapshotsDir(mfs.getRootDir());
      if (fs.exists(snapshotDir)) {
        FileStatus[] snapshots =
            FSUtils.listStatus(
                fs,
                snapshotDir,
                new SnapshotDescriptionUtils.CompletedSnaphotDirectoriesFilter(fs));
        if (snapshots != null) {
          LOG.error("Snapshots are present, but cleaners are not enabled.");
          checkSnapshotSupport();
        }
      }
    }
  }
 /**
  * Create the namespace directory
  *
  * @param env MasterProcedureEnv
  * @param nsDescriptor NamespaceDescriptor
  * @throws IOException
  */
 protected static void createDirectory(
     final MasterProcedureEnv env, final NamespaceDescriptor nsDescriptor) throws IOException {
   MasterFileSystem mfs = env.getMasterServices().getMasterFileSystem();
   mfs.getFileSystem().mkdirs(FSUtils.getNamespaceDir(mfs.getRootDir(), nsDescriptor.getName()));
 }