@Override
  protected boolean isRollbackSupported(final CreateNamespaceState state) {
    switch (state) {
      case CREATE_NAMESPACE_PREPARE:
        return true;
      default:
        return false;
    }
  }
The procedure to create a new namespace.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/procedure/CreateNamespaceProcedure.java