private FileSystem getFileSystem(List<String> filePaths) throws IOException {
    if (filePaths.isEmpty()) {
      // local hdfs
      return server.getFileSystem();
    }
    // source hdfs
    return new Path(filePaths.get(0)).getFileSystem(server.getConfiguration());
  }
Atomically bulk load several HFiles into an open region
@return true if successful, false is failed but recoverably (no action)
@throws ServiceException if failed unrecoverably
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/RSRpcServices.java