[misc] Add retries with exponential backoff for HF file existence check

vllm/transformers_utils/config.py

@@ -5,7 +5,7 @@
 import os
 from pathlib import Path
 from typing import Any, Dict, Literal, Optional, Type, Union
-
+import time
 import huggingface_hub
 from huggingface_hub import (file_exists, hf_hub_download, list_repo_files,
                              try_to_load_from_cache)
@@ -100,15 +100,26 @@
 
     # NB: file_exists will only check for the existence of the config file on
     # hf_hub. This will fail in offline mode.
-    try:
-        return file_exists(model,
-                           config_name,
-                           revision=revision,
-                           token=HF_TOKEN)
-    except huggingface_hub.errors.OfflineModeIsEnabled:
-        # Don't raise in offline mode, all we know is that we don't have this
-        # file cached.
-        return False
+
+    # Call HF to check if the file exists, with 3 retries and exponential backoff
+    max_retries = 3
+    retry_delay = 2
+    for attempt in range(max_retries):
+        try:
+            return file_exists(model,
+                             config_name,
+                             revision=revision,
+                             token=HF_TOKEN)
+        except huggingface_hub.errors.OfflineModeIsEnabled:
+            # Don't raise in offline mode, all we know is that we don't have this
+            # file cached.
+            return False
+        except Exception as e:
+            logger.error(f"Error checking file existence: {e}")
+            if attempt == max_retries - 1:
+                raise
+            time.sleep(retry_delay)
+            retry_delay *= 2
 
 
 def patch_rope_scaling(config: PretrainedConfig) -> None:
@@ -193,10 +204,22 @@
             # raise an offline mode error to indicate to the user that they
             # don't have files cached and may need to go online.
             # This is conveniently triggered by calling file_exists().
-            file_exists(model,
-                        HF_CONFIG_NAME,
-                        revision=revision,
-                        token=HF_TOKEN)
+
+            # Call HF to check if the file exists, with 3 retries and exponential backoff
+            max_retries = 3
+            retry_delay = 2
+            for attempt in range(max_retries):
+                try:
+                    file_exists(model,
+                                HF_CONFIG_NAME,
+                                revision=revision,
+                                token=HF_TOKEN)
+                except Exception as e:
+                    logger.error(f"Error checking file existence: {e}")
+                    if attempt == max_retries - 1:
+                        raise e
+                    time.sleep(retry_delay)
+                    retry_delay *= 2
 
             raise ValueError(f"No supported config format found in {model}")