I’m trying to subclass ModelCheckpoint and I’m curious about an implementation detail on distributed environments. When saving the checkpoint, the callback will call:
self._write_filepath = distributed_file_utils.write_filepath(file_path, self.model.distribute_strategy)

which tests if the model is being executed in a distributed environment, and, returns the original file_path for the “chief worker”, and a temporary file path for all other workers. The callback will then call:
distributed_file_utils.remove_temp_dir_with_filepath(self._write_filepath, self.model.distribute_strategy)

which deletes the temporary file_path for the non-chief workers, and leave the original file_path for the original worker.
My question is: why this roundabout way of doing things? Why not simply check whether the worker is the chief one, and save the checkpoint only if that is true?