[Fix] Failed to remove the previous best checkpoints

mmengine/hooks/checkpoint_hook.py

@@ -479,9 +479,9 @@ def _save_best_checkpoint(self, runner, metrics) -> None:
             runner.message_hub.update_info(best_score_key, best_score)
 
             if best_ckpt_path and \
-               self.file_client.isfile(best_ckpt_path) and \
+               self.file_backend.isfile(best_ckpt_path) and \
                is_main_process():
-                self.file_client.remove(best_ckpt_path)
+                self.file_backend.remove(best_ckpt_path)
                 runner.logger.info(
                     f'The previous best checkpoint {best_ckpt_path} '
                     'is removed')
@@ -490,13 +490,13 @@ def _save_best_checkpoint(self, runner, metrics) -> None:
             # Replace illegal characters for filename with `_`
             best_ckpt_name = best_ckpt_name.replace('/', '_')
             if len(self.key_indicators) == 1:
-                self.best_ckpt_path = self.file_client.join_path(  # type: ignore # noqa: E501
+                self.best_ckpt_path = self.file_backend.join_path(  # type: ignore # noqa: E501
                     self.out_dir, best_ckpt_name)
                 runner.message_hub.update_info(runtime_best_ckpt_key,
                                                self.best_ckpt_path)
             else:
                 self.best_ckpt_path_dict[
-                    key_indicator] = self.file_client.join_path(  # type: ignore # noqa: E501
+                    key_indicator] = self.file_backend.join_path(  # type: ignore # noqa: E501
                         self.out_dir, best_ckpt_name)
                 runner.message_hub.update_info(
                     runtime_best_ckpt_key,

mmengine/runner/runner.py

@@ -2191,7 +2191,11 @@ def save_checkpoint(
                     checkpoint['param_schedulers'].append(state_dict)
 
         self.call_hook('before_save_checkpoint', checkpoint=checkpoint)
-        save_checkpoint(checkpoint, filepath)
+        save_checkpoint(
+            checkpoint,
+            filepath,
+            file_client_args=file_client_args,
+            backend_args=backend_args)
 
     @master_only
     def dump_config(self) -> None:

mmengine/testing/runner_test_case.py

@@ -2,6 +2,7 @@
 import copy
 import logging
 import os
+import shutil
 import tempfile
 import time
 from unittest import TestCase
@@ -184,3 +185,12 @@ def setup_dist_env(self):
         os.environ['RANK'] = self.dist_cfg['RANK']
         os.environ['WORLD_SIZE'] = self.dist_cfg['WORLD_SIZE']
         os.environ['LOCAL_RANK'] = self.dist_cfg['LOCAL_RANK']
+
+    def clear_work_dir(self):
+        logging.shutdown()
+        for filename in os.listdir(self.temp_dir.name):
+            filepath = os.path.join(self.temp_dir.name, filename)
+            if os.path.isfile(filepath):
+                os.remove(filepath)
+            else:
+                shutil.rmtree(filepath)

tests/test_hooks/test_checkpoint_hook.py

@@ -3,6 +3,8 @@
 import os
 import os.path as osp
 import re
+import sys
+from unittest.mock import MagicMock, patch
 
 import torch
 from parameterized import parameterized
@@ -312,6 +314,54 @@ def test_after_val_epoch(self):
         self.assertFalse(
             osp.isfile(osp.join(runner.work_dir, 'last_checkpoint')))
 
+        # There should only one best checkpoint be reserved
+        # dist backend
+        for by_epoch, cfg in [(True, self.epoch_based_cfg),
+                              (False, self.iter_based_cfg)]:
+            self.clear_work_dir()
+            cfg = copy.deepcopy(cfg)
+            runner = self.build_runner(cfg)
+            checkpoint_hook = CheckpointHook(
+                interval=2, by_epoch=by_epoch, save_best='acc')
+            checkpoint_hook.before_train(runner)
+            checkpoint_hook.after_val_epoch(runner, metrics)
+            all_files = os.listdir(runner.work_dir)
+            best_ckpts = [
+                file for file in all_files if file.startswith('best')
+            ]
+            self.assertTrue(len(best_ckpts) == 1)
+
+        # petrel backend
+        # TODO use real petrel oss bucket to test
+        petrel_client = MagicMock()
+        for by_epoch, cfg in [(True, self.epoch_based_cfg),
+                              (False, self.iter_based_cfg)]:
+            isfile = MagicMock(return_value=True)
+            self.clear_work_dir()
+            with patch.dict(sys.modules, {'petrel_client': petrel_client}), \
+                 patch('mmengine.fileio.backends.PetrelBackend.put') as put_mock, \
+                 patch('mmengine.fileio.backends.PetrelBackend.remove') as remove_mock, \
+                 patch('mmengine.fileio.backends.PetrelBackend.isfile') as isfile:  # noqa: E501
+                cfg = copy.deepcopy(cfg)
+                runner = self.build_runner(cfg)
+                metrics = dict(acc=0.5)
+                petrel_client.client.Client = MagicMock(
+                    return_value=petrel_client)
+                checkpoint_hook = CheckpointHook(
+                    interval=2,
+                    by_epoch=by_epoch,
+                    save_best='acc',
+                    backend_args=dict(backend='petrel'))
+                checkpoint_hook.before_train(runner)
+                checkpoint_hook.after_val_epoch(runner, metrics)
+                put_mock.assert_called_once()
+                metrics['acc'] += 0.1
+                runner.train_loop._epoch += 1
+                runner.train_loop._iter += 1
+                checkpoint_hook.after_val_epoch(runner, metrics)
+                isfile.assert_called_once()
+                remove_mock.assert_called_once()
+
     def test_after_train_epoch(self):
         cfg = copy.deepcopy(self.epoch_based_cfg)
         runner = self.build_runner(cfg)

tests/test_runner/test_checkpoint.py

@@ -20,9 +20,6 @@
                                         load_from_local, load_from_pavi,
                                         save_checkpoint)
 
-sys.modules['petrel_client'] = MagicMock()
-sys.modules['petrel_client.client'] = MagicMock()
-
 
 @MODEL_WRAPPERS.register_module()
 class DDPWrapper:
@@ -150,9 +147,8 @@ def test_get_state_dict():
                         wrapped_model.module.conv.module.bias)
 
 
+@patch.dict(sys.modules, {'pavi': MagicMock()})
 def test_load_pavimodel_dist():
-    sys.modules['pavi'] = MagicMock()
-    sys.modules['pavi.modelcloud'] = MagicMock()
     pavimodel = Mockpavimodel()
     import pavi
     pavi.modelcloud.get = MagicMock(return_value=pavimodel)
@@ -296,6 +292,7 @@ def _load_from_state_dict(self, state_dict, prefix, local_metadata,
     assert torch.allclose(model_v2.conv1.weight, model_v2_conv1_weight)
 
 
+@patch.dict(sys.modules, {'petrel_client': MagicMock()})
 def test_checkpoint_loader():
     filenames = [
         'http://xx.xx/xx.pth', 'https://xx.xx/xx.pth',