Sort callbacks so that CheckpointSaver goes before HuggingFaceCheckpo…

…inter (#1515)

llmfoundry/command_utils/train.py

@@ -10,6 +10,7 @@
 import torch
 import torch.distributed
 from composer import ComposerModel, Trainer
+from composer.callbacks.checkpoint_saver import CheckpointSaver
 from composer.core.callback import Callback
 from composer.profiler import (
     JSONTraceHandler,
@@ -187,6 +188,24 @@ def _initialize_dist_with_barrier(dist_timeout: Union[int, float]):
     log.debug('Barrier test passed with device.')
 
 
+def _sort_callbacks(trainer: Trainer):
+    """Sort callback so that checkpoint saving callbacks go first.
+
+    Args:
+        trainer (Trainer): Trainer object
+    """
+
+    def _sort_key(c: Callback) -> int:
+        # CheckpointSaver goes before HuggingFaceCheckpointer because the blocking time is shortest while upload is async.
+        if isinstance(c, CheckpointSaver):
+            return 1
+        if isinstance(c, HuggingFaceCheckpointer):
+            return 2
+        return 0
+
+    trainer.state.callbacks = sorted(trainer.state.callbacks, key=_sort_key)
+
+
 def train(cfg: DictConfig) -> Trainer:
     code_paths = cfg.get('code_paths', [])
     # Import any user provided code
@@ -548,6 +567,8 @@ def train(cfg: DictConfig) -> Trainer:
         spin_dataloaders=train_cfg.spin_dataloaders,
     )
 
+    _sort_callbacks(trainer)
+
     # Optionally just save an HF checkpoint
     if train_cfg.only_hf_checkpoint:
         hf_checkpointer_callbacks = [

tests/a_scripts/train/test_train.py

@@ -5,14 +5,18 @@
 import os
 import pathlib
 from typing import Optional
+from unittest.mock import Mock
 
 import pytest
+from composer.callbacks import CheckpointSaver
 from composer.loggers import InMemoryLogger
 from omegaconf import DictConfig, ListConfig
 from omegaconf import OmegaConf as om
 
+from llmfoundry.callbacks import HuggingFaceCheckpointer, RunTimeoutCallback
 from llmfoundry.command_utils import TrainConfig  # noqa: E402
 from llmfoundry.command_utils import TRAIN_CONFIG_KEYS, train, validate_config
+from llmfoundry.command_utils.train import _sort_callbacks
 from llmfoundry.utils.config_utils import (
     make_dataclass_and_log_config,
     update_batch_size_info,
@@ -110,6 +114,20 @@ def test_train_gauntlet(averages: Optional[dict], tmp_path: pathlib.Path):
         -1][-1] == 0
 
 
+def test_sort_callbacks():
+    trainer_mock = Mock()
+    trainer_mock.state.callbacks = [
+        CheckpointSaver(),
+        HuggingFaceCheckpointer('save-folder', '1ba'),
+        RunTimeoutCallback(),
+    ]
+    _sort_callbacks(trainer_mock)
+
+    assert isinstance(trainer_mock.state.callbacks[0], RunTimeoutCallback)
+    assert isinstance(trainer_mock.state.callbacks[1], CheckpointSaver)
+    assert isinstance(trainer_mock.state.callbacks[2], HuggingFaceCheckpointer)
+
+
 def test_train_multi_eval(tmp_path: pathlib.Path):
     """Test training run with multiple eval datasets."""
     c4_dataset_name = create_c4_dataset_xxsmall(tmp_path)