fix: enhance error handling for Google Drive file downloads with SSL retries

src/connectors/google_drive/connector.py

@@ -1,6 +1,7 @@
 import asyncio
 import io
 import os
+import ssl
 import time
 from collections import deque
 from collections.abc import Iterable
@@ -509,34 +510,62 @@ def _download_file_bytes(self, file_meta: dict[str, Any]) -> bytes:
                 # Binary download (get_media also doesn't accept the Drive flags)
                 request = self.service.files().get_media(fileId=file_id)
 
-            # Download the file with error handling for misclassified Google Docs
+        # Download the file with error handling for misclassified Google Docs and
+        # transient SSL/network errors. Each SSL retry recreates the downloader
+        # from scratch to avoid partial-buffer state.
+        _max_retries = 3
+        for _attempt in range(_max_retries):
             fh = io.BytesIO()
             downloader = MediaIoBaseDownload(fh, request, chunksize=1024 * 1024)
             done = False
-
+            _should_retry = False
+            _delay = 0.0
+            _err: Exception | None = None
             try:
-                while not done:
-                    status, done = downloader.next_chunk()
-                    # Optional: you can log progress via status.progress()
-            except HttpError as e:
-                # If download fails with "fileNotDownloadable", it's a Docs Editor file
-                # that wasn't properly detected. Retry with export_media.
-                if "fileNotDownloadable" in str(e) and mime_type not in exportable_types:
-                    logger.warning(
-                        f"Download failed for {file_id} ({mime_type}) with fileNotDownloadable error. "
-                        f"Retrying with export_media (file might be a Google Doc)"
-                    )
-                    export_mime = "application/pdf"
-                    request = self.service.files().export_media(
-                        fileId=file_id, mimeType=export_mime
-                    )
-                    fh = io.BytesIO()
-                    downloader = MediaIoBaseDownload(fh, request, chunksize=1024 * 1024)
-                    done = False
+                try:
                     while not done:
                         status, done = downloader.next_chunk()
-                else:
-                    raise
+                except HttpError as e:
+                    # If download fails with "fileNotDownloadable", it's a Docs Editor file
+                    # that wasn't properly detected. Retry with export_media.
+                    if "fileNotDownloadable" in str(e) and mime_type not in exportable_types:
+                        logger.warning(
+                            f"Download failed for {file_id} ({mime_type}) with fileNotDownloadable error. "
+                            f"Retrying with export_media (file might be a Google Doc)"
+                        )
+                        export_mime = "application/pdf"
+                        with self._lock:
+                            request = self.service.files().export_media(
+                                fileId=file_id, mimeType=export_mime
+                            )
+                        fh = io.BytesIO()
+                        downloader = MediaIoBaseDownload(fh, request, chunksize=1024 * 1024)
+                        done = False
+                        while not done:
+                            status, done = downloader.next_chunk()
+                    else:
+                        raise
+                break  # download succeeded
+            except (ssl.SSLError, ConnectionResetError, TimeoutError) as e:
+                _should_retry = _attempt < _max_retries - 1
+                _delay = 2.0**_attempt
+                _err = e
+
+            if _should_retry and _err is not None:
+                logger.warning(
+                    "[GoogleDrive] Transient network error for %s (attempt %d/%d), "
+                    "retrying in %.1fs: %s",
+                    file_id,
+                    _attempt + 1,
+                    _max_retries,
+                    _delay,
+                    _err,
+                )
+                time.sleep(_delay)
+                continue
+
+            if _err is not None:
+                raise _err
 
         data = fh.getvalue()
         logger.debug("[GoogleDrive] _download_file_bytes: done, %d bytes", len(data))