[DCP] Fix duplicated logging messages when enable both c10d and dcp l… (#130423)

…ogger

Fixes #129951 . Would you take a moment to review it? @LucasLLC

Pull Request resolved: https://github.com/pytorch/pytorch/pull/130423
Approved by: https://github.com/Skylion007

test/distributed/checkpoint/test_utils.py

@@ -11,6 +11,8 @@ from torch.distributed._shard.sharded_tensor import (
     ShardMetadata,
 )
 from torch.distributed._shard.sharded_tensor.metadata import TensorProperties
+from torch.distributed.c10d_logger import _c10d_logger
+from torch.distributed.checkpoint.logger import _dcp_logger
 from torch.distributed.checkpoint.metadata import MetadataIndex
 from torch.distributed.checkpoint.utils import find_state_dict_object
 
@@ -122,6 +124,10 @@ class TestMedatadaIndex(TestCase):
         with self.assertRaisesRegex(ValueError, "Could not find shard"):
             find_state_dict_object(state_dict, MetadataIndex("st", [1]))
 
+    def test_dcp_logger(self):
+        self.assertTrue(_c10d_logger is not _dcp_logger)
+        self.assertEqual(1, len(_c10d_logger.handlers))
+
 
 if __name__ == "__main__":
     run_tests()

torch/distributed/c10d_logger.py

@@ -40,7 +40,7 @@ def _get_logging_handler(
     destination: str = _DEFAULT_DESTINATION,
 ) -> Tuple[logging.Handler, str]:
     log_handler = _log_handlers[destination]
-    log_handler_name = type(log_handler).__name__
+    log_handler_name = f"{type(log_handler).__name__}-{destination}"
     return (log_handler, log_handler_name)