@Override
 public boolean isBlockCacheEnabled(String cluster, String table) {
   LOG.debug("trace isBlockCacheEnabled");
   try {
     if (_zk.exists(
             ZookeeperPathConstants.getTableBlockCachingFileTypesPath(cluster, table), false)
         == null) {
       return false;
     }
   } catch (KeeperException e) {
     throw new RuntimeException(e);
   } catch (InterruptedException e) {
     throw new RuntimeException(e);
   }
   return true;
 }
 @Override
 public Set<String> getBlockCacheFileTypes(String cluster, String table) {
   LOG.debug("trace getBlockCacheFileTypes");
   try {
     byte[] data =
         getData(ZookeeperPathConstants.getTableBlockCachingFileTypesPath(cluster, table));
     if (data == null) {
       return null;
     }
     String str = new String(data);
     if (str.isEmpty()) {
       return null;
     }
     Set<String> types = new HashSet<String>(Arrays.asList(str.split(",")));
     if (types.isEmpty()) {
       return null;
     }
     return types;
   } catch (KeeperException e) {
     throw new RuntimeException(e);
   } catch (InterruptedException e) {
     throw new RuntimeException(e);
   }
 }