checkpointer._clean_up_old_checkpoints not working as intended/documented?

[rocanaan]

Hello,

The documentation of checkpoint.py states that the checkpointer will delete all but the last CHECKPOINT_DURATION checkpoint files. In the example, it says this would apply both to cpkt files and sentinel_checkpoint_complete files.

However, in my experiments this is not the case. It removes the old tf_ckpt* files, but not any of the others (including sentinel_checkpoint_complete and ckpt, but also actions_ckpt, add_count_ckpt, invalid_range_ckpt, legal_actions_ckpt etc).

Is this intended behavior? The comments at the start of the could seem to imply that it should remove all older files, but in practice only one of the many types of files is being removed, which doesn't that much space (which seems to be the reason for implementing the clean up in the first place).

If this is not intended, I can add the fix to a pull request.