Add fall back to all exceptions encountered when presigned URL is not available for upload and download in FilesExt

NEXT_CHANGELOG.md

@@ -9,6 +9,8 @@
 
 ### Bug Fixes
 
+- Fixed an issue where download from Shared Volumes could fail by falling back to Files API whenever Presigned URLs are not available.
+
 ### Documentation
 
 ### Internal Changes

databricks/sdk/mixins/files.py

@@ -964,6 +964,8 @@ def _parallel_download_presigned_url(self, remote_path: str, destination: str, p
 
         cloud_session = self._create_cloud_provider_session()
         url_distributor = _PresignedUrlDistributor(lambda: self._create_download_url(remote_path))
+        # An event to indicate if any download chunk has succeeded. If any chunk succeeds, we do not fall back to Files API.
+        any_success = Event()
 
         def download_chunk(additional_headers: dict[str, str]) -> BinaryIO:
             retry_count = 0
@@ -982,10 +984,14 @@ def get_content() -> requests.Response:
                     url_distributor.invalidate_url(version)
                     retry_count += 1
                     continue
-                elif raw_resp.status_code == 403:
+                elif raw_resp.status_code == 403 and not any_success.is_set():
                     raise FallbackToDownloadUsingFilesApi("Received 403 Forbidden from presigned URL")
+                elif not any_success.is_set():
+                    # For other errors, we raise a retryable exception to trigger retry logic.
+                    raise FallbackToDownloadUsingFilesApi(f"Received {raw_resp.status_code} from presigned URL")
 
                 raw_resp.raise_for_status()
+                any_success.set()
                 return BytesIO(raw_resp.content)
             raise ValueError("Exceeded maximum retries for downloading with presigned URL: URL expired too many times")
 
@@ -1404,20 +1410,47 @@ def _parallel_multipart_upload_from_file(
         part_size = ctx.part_size
         num_parts = (file_size + part_size - 1) // part_size
         _LOG.debug(f"Uploading file of size {file_size} bytes in {num_parts} parts using {ctx.parallelism} threads")
+        cloud_provider_session = self._create_cloud_provider_session()
+
+        # Upload one part to verify the upload can proceed.
+        with open(ctx.source_file_path, "rb") as f:
+            f.seek(0)
+            first_part_size = min(part_size, file_size)
+            first_part_buffer = f.read(first_part_size)
+            try:
+                etag = self._do_upload_one_part(
+                    ctx,
+                    cloud_provider_session,
+                    1,
+                    0,
+                    first_part_size,
+                    session_token,
+                    BytesIO(first_part_buffer),
+                    is_first_part=True,
+                )
+            except FallbackToUploadUsingFilesApi as e:
+                raise FallbackToUploadUsingFilesApi(None, "Falling back to single-shot upload with Files API") from e
+        if num_parts == 1:
+            self._complete_multipart_upload(ctx, {1: etag}, session_token)
+            return
 
         # Create queues and worker threads.
         task_queue = Queue()
         etags_result_queue = Queue()
+        etags_result_queue.put_nowait((1, etag))
         exception_queue = Queue()
         aborted = Event()
         workers = [
-            Thread(target=self._upload_file_consumer, args=(task_queue, etags_result_queue, exception_queue, aborted))
+            Thread(
+                target=self._upload_file_consumer,
+                args=(cloud_provider_session, task_queue, etags_result_queue, exception_queue, aborted),
+            )
             for _ in range(ctx.parallelism)
         ]
         _LOG.debug(f"Starting {len(workers)} worker threads for parallel upload")
 
         # Enqueue all parts. Since the task queue is populated before starting the workers, we don't need to signal completion.
-        for part_index in range(1, num_parts + 1):
+        for part_index in range(2, num_parts + 1):
             part_offset = (part_index - 1) * part_size
             part_size = min(part_size, file_size - part_offset)
             part = self._MultipartUploadPart(ctx, part_index, part_offset, part_size, session_token)
@@ -1466,7 +1499,14 @@ def _parallel_multipart_upload_from_stream(
             )
         try:
             etag = self._do_upload_one_part(
-                ctx, cloud_provider_session, 1, 0, len(pre_read_buffer), session_token, BytesIO(pre_read_buffer)
+                ctx,
+                cloud_provider_session,
+                1,
+                0,
+                len(pre_read_buffer),
+                session_token,
+                BytesIO(pre_read_buffer),
+                is_first_part=True,
             )
             etags_result_queue.put((1, etag))
         except FallbackToUploadUsingFilesApi as e:
@@ -1551,12 +1591,12 @@ def _complete_multipart_upload(self, ctx, etags, session_token):
 
     def _upload_file_consumer(
         self,
+        cloud_provider_session: requests.Session,
         task_queue: Queue[FilesExt._MultipartUploadPart],
         etags_queue: Queue[tuple[int, str]],
         exception_queue: Queue[Exception],
         aborted: Event,
     ) -> None:
-        cloud_provider_session = self._create_cloud_provider_session()
         while not aborted.is_set():
             try:
                 part = task_queue.get(block=False)
@@ -1627,6 +1667,7 @@ def _do_upload_one_part(
         part_size: int,
         session_token: str,
         part_content: BinaryIO,
+        is_first_part: bool = False,
     ) -> str:
         retry_count = 0
 
@@ -1648,18 +1689,14 @@ def _do_upload_one_part(
                 upload_part_urls_response = self._api.do(
                     "POST", "/api/2.0/fs/create-upload-part-urls", headers=headers, body=body
                 )
-            except PermissionDenied as e:
-                if self._is_presigned_urls_disabled_error(e):
-                    raise FallbackToUploadUsingFilesApi(None, "Presigned URLs are disabled")
-                else:
-                    raise e from None
-            except InternalError as e:
-                if self._is_presigned_urls_network_zone_error(e):
+            except Exception as e:
+                if is_first_part:
                     raise FallbackToUploadUsingFilesApi(
-                        None, "Presigned URLs are not supported in the current network zone"
+                        None,
+                        f"Failed to obtain upload URL for part {part_index}: {e}, falling back to single shot upload",
                     )
                 else:
-                    raise e from None
+                    raise e
 
             upload_part_urls = upload_part_urls_response.get("upload_part_urls", [])
             if len(upload_part_urls) == 0:
@@ -1699,8 +1736,11 @@ def perform_upload() -> requests.Response:
                     continue
                 else:
                     raise ValueError(f"Unsuccessful chunk upload: upload URL expired after {retry_count} retries")
-            elif upload_response.status_code == 403:
+            elif upload_response.status_code == 403 and is_first_part:
                 raise FallbackToUploadUsingFilesApi(None, f"Direct upload forbidden: {upload_response.content}")
+            elif is_first_part:
+                message = f"Unsuccessful chunk upload. Response status: {upload_response.status_code}, body: {upload_response.content}"
+                raise FallbackToUploadUsingFilesApi(None, message)
             else:
                 message = f"Unsuccessful chunk upload. Response status: {upload_response.status_code}, body: {upload_response.content}"
                 _LOG.warning(message)
@@ -1765,18 +1805,13 @@ def _perform_multipart_upload(
                 upload_part_urls_response = self._api.do(
                     "POST", "/api/2.0/fs/create-upload-part-urls", headers=headers, body=body
                 )
-            except PermissionDenied as e:
-                if chunk_offset == 0 and self._is_presigned_urls_disabled_error(e):
-                    raise FallbackToUploadUsingFilesApi(buffer, "Presigned URLs are disabled")
-                else:
-                    raise e from None
-            except InternalError as e:
-                if chunk_offset == 0 and self._is_presigned_urls_network_zone_error(e):
+            except Exception as e:
+                if chunk_offset == 0:
                     raise FallbackToUploadUsingFilesApi(
-                        buffer, "Presigned URLs are not supported in the current network zone"
-                    )
+                        buffer, f"Failed to obtain upload URLs: {e}, falling back to single shot upload"
+                    ) from e
                 else:
-                    raise e from None
+                    raise e
 
             upload_part_urls = upload_part_urls_response.get("upload_part_urls", [])
             if len(upload_part_urls) == 0:
@@ -1847,7 +1882,14 @@ def perform():
                     # Let's fallback to using Files API which might be allowlisted to upload, passing
                     # currently buffered (but not yet uploaded) part of the stream.
                     raise FallbackToUploadUsingFilesApi(buffer, f"Direct upload forbidden: {upload_response.content}")
-
+                elif chunk_offset == 0:
+                    # We got an upload failure when uploading the very first chunk.
+                    # Let's fallback to using Files API which might be more reliable in this case,
+                    # passing currently buffered (but not yet uploaded) part of the stream.
+                    raise FallbackToUploadUsingFilesApi(
+                        buffer,
+                        f"Unsuccessful chunk upload: {upload_response.status_code}, falling back to single shot upload",
+                    )
                 else:
                     message = f"Unsuccessful chunk upload. Response status: {upload_response.status_code}, body: {upload_response.content}"
                     _LOG.warning(message)
@@ -1985,18 +2027,10 @@ def _perform_resumable_upload(
             resumable_upload_url_response = self._api.do(
                 "POST", "/api/2.0/fs/create-resumable-upload-url", headers=headers, body=body
             )
-        except PermissionDenied as e:
-            if self._is_presigned_urls_disabled_error(e):
-                raise FallbackToUploadUsingFilesApi(pre_read_buffer, "Presigned URLs are disabled")
-            else:
-                raise e from None
-        except InternalError as e:
-            if self._is_presigned_urls_network_zone_error(e):
-                raise FallbackToUploadUsingFilesApi(
-                    pre_read_buffer, "Presigned URLs are not supported in the current network zone"
-                )
-            else:
-                raise e from None
+        except Exception as e:
+            raise FallbackToUploadUsingFilesApi(
+                pre_read_buffer, f"Failed to obtain resumable upload URL: {e}, falling back to single shot upload"
+            ) from e
 
         resumable_upload_url_node = resumable_upload_url_response.get("resumable_upload_url")
         if not resumable_upload_url_node:
@@ -2376,16 +2410,8 @@ def _create_download_url(self, file_path: str) -> CreateDownloadUrlResponse:
             )
 
             return CreateDownloadUrlResponse.from_dict(raw_response)
-        except PermissionDenied as e:
-            if self._is_presigned_urls_disabled_error(e):
-                raise FallbackToDownloadUsingFilesApi(f"Presigned URLs are disabled")
-            else:
-                raise e from None
-        except InternalError as e:
-            if self._is_presigned_urls_network_zone_error(e):
-                raise FallbackToDownloadUsingFilesApi("Presigned URLs are not supported in the current network zone")
-            else:
-                raise e from None
+        except Exception as e:
+            raise FallbackToDownloadUsingFilesApi(f"Failed to create download URL: {e}") from e
 
     def _init_download_response_presigned_api(self, file_path: str, added_headers: dict[str, str]) -> DownloadResponse:
         """
@@ -2428,17 +2454,11 @@ def perform() -> requests.Response:
                 contents=_StreamingResponse(csp_response, self._config.files_ext_client_download_streaming_chunk_size),
             )
             return resp
-        elif csp_response.status_code == 403:
-            # We got 403 failure when downloading the file. This might happen due to Azure firewall enabled for the customer bucket.
-            # Let's fallback to using Files API which might be allowlisted to download.
-            raise FallbackToDownloadUsingFilesApi(f"Direct download forbidden: {csp_response.content}")
         else:
             message = (
                 f"Unsuccessful download. Response status: {csp_response.status_code}, body: {csp_response.content}"
             )
-            _LOG.warning(message)
-            mapped_error = _error_mapper(csp_response, {})
-            raise mapped_error or ValueError(message)
+            raise FallbackToDownloadUsingFilesApi(message)
 
     def _init_download_response_mode_csp_with_fallback(
         self, file_path: str, headers: dict[str, str], response_headers: list[str]